specification heating & domestic services · pdf file · 2016-02-122.40...

DAVID MILES & PARTNERS Building Services Consulting Engineers 5 Holgate Court, Western Road, Romford, Essex, RM1 3JS Tel no: 01708 729070 Fax no. 01708 755024 www.davidmiles.co.uk

Version No: 001 Revision No: 000 Date: February 2016

Job No: 6658

SPECIFICATION HEATING & DOMESTIC SERVICES REFURBISHMENT

at:

MEAKINS ESTATE DECIMA STREET LONDON SE1 4QR For:

LEATHERMARKET JMB 26 LEATHERMARKET STREET

LONDON

SE1 3HN

SPECIFICATION REVISIONS RECORD Version No. Rev. No. Date Purpose / Revision Detail

001 001 February 2016 For Tender

002

003

Compiled by: Chris O’Meara Checked by: Tony Baker

THIS SPECIFICATION IS DIVIDED INTO THE FOLLOWING SECTIONS:

SECTION ONE PRELIMINARIES and BONA FIDE TENDER

SECTION TWO STANDARDS OF MATERIALS AND WORKMANSHIP - MECHANICAL SERVICES SECTION THREE PARTICULAR REQUIREMENTS – MECHANICAL SERVICES SECTION FOUR STANDARDS OF MATERIALS AND WORKMANSHIP ELECTRICAL SERVICES SECTION FIVE UNDERGROUND MAINS STANDARDS

PRICING DOCUMENT – MECHANICAL AND ELECTRICAL

SERVICES

MEAKIN ESTATE - HEATING & DOMESTIC SERVICES REFURBISHMENT

CERTIFICATE OF BONA FIDE TENDER

The essence of tendering is that Leathermarket JMB shall receive bona fide competitive Tenders from all firms tendering. In recognition of this principle, we certify that this is a bona fide Tender, intended to be competitive, and that we have not fixed or adjusted the amount of the Tender by or under or in accordance with any agreement or arrangement with any other person. We also certify that we have not done and we undertake that we will not do at any time before the returnable date for this tender any of the following acts: (a) Communicating to a person other than the person calling for these Tenders the amount or approximate amount of the proposed Tender; (b) Entering into any arrangement or agreement with any other person that he shall refrain from Tendering or as to the amount of any Tender to be submitted; (c) Offering or paying or giving or agreeing to pay or give any sum of money or valuable consideration directly or indirectly to any person for doing or having done or causing or having caused to be done in relation to any other Tender or proposed Tender for the said work any act or thing of the sort described above. In this Certificate, the word "person" includes any persons and any body or association, corporate or un-incorporate, and "any arrangement" includes any such transaction, formal or informal, and whether legally binding or not, and the plural includes the singular. SIGNED: ON BEHALF OF: DATE:

SECTION TWO

STANDARDS OF MATERIALS AND WORKMANSHIP – MECHANICAL

THE MATERIALS AND WORKMANSHIP DETAILED IN THIS SECTION APPLY EVEN IF NOT DETAILED IN THE RELEVANT PARTICULAR REQUIREMENTS SECTION

2. SECTION TWO ..................................................................................................................................... 1

STANDARDS OF MATERIALS AND WORKMANSHIP – MECHANICAL............................................ 1

2.1 STANDARDS ........................................................................................................................................ 1

2.2 MATERIALS AND WORKMANSHIP (STANDARDS) ........................................................................... 1

2.3 MANUFACTURERS FINISH ................................................................................................................. 2

2.4 ACCESSIBILITY .................................................................................................................................... 2

2.5 PIPEWORK AND FITTINGS ................................................................................................................. 2

2.6 RUN OF PIPEWORK ............................................................................................................................ 3

2.7 PIPEWORK ........................................................................................................................................... 3

2.8 SCREWED PIPE JOINTING ................................................................................................................. 7

2.9 FLANGED JOINTS ................................................................................................................................ 7

2.10 WELDED PIPEWORK ........................................................................................................................... 7

2.11 ERECTION OF PIPEWORK ................................................................................................................. 9

2.12 PIPE SUPPORTS ............................................................................................................................... 10

2.13 PIPE SLEEVES ................................................................................................................................... 11

2.14 WALL AND FLOOR PLATES .............................................................................................................. 12

2.15 TESTING PIPEWORK ........................................................................................................................ 12

2.16 STORAGE OF PIPEWORK ................................................................................................................ 12

2.17 PREVENTION OF DIRT ENTERING PIPE, VALVES, ETC ............................................................... 13

2.18 EXPANSION ........................................................................................................................................ 13

2.19 ANCHORS AND GUIDES ................................................................................................................... 13

2.20 VALVES AND COCKS ........................................................................................................................ 14

2.21 VALVE KEYS ...................................................................................................................................... 17

2.22 AUTOMATIC AIR VENTS ................................................................................................................... 17

2.23 AIR COCKS AND BOTTLES ............................................................................................................... 17

2.24 DRAIN COCKS.................................................................................................................................... 17

2.25 PRESSURE GAUGES ........................................................................................................................ 18

2.26 THERMOMETERS .............................................................................................................................. 18

2.27 BOILER SAFETY VALVE .................................................................................................................... 18

2.28 STRAINERS AND TEST POINTS....................................................................................................... 19

2.29 WATER REGULATIONS ..................................................................................................................... 19

2.30 LEGIONELLA CONTROL ................................................................................................................... 19

2.31 SUPPORTING STRUCTURES AND BRACKETS .............................................................................. 20

2.32 SPARES AND TOOLS ........................................................................................................................ 20

2.33 GUARDS TO PROTECT PLANT ........................................................................................................ 20

2.34 LUBRICATION .................................................................................................................................... 20

2.35 PREVENTION OF NOISE AND VIBRATION ...................................................................................... 20

2.36 INCOMING WATER MAINS ................................................................................................................ 20

2.37 CISTERNS AND TANKS ..................................................................................................................... 20

2.38 OVERFLOW AND OTHER WARNING PIPES ................................................................................... 21

2.39 PAINTING GALVANISED TANKS ...................................................................................................... 21

2.40 PREPARATION FOR PAINTING, PAINTING, CLEANING THE WORKS ON COMPLETION .......... 21

2.41 THERMAL INSULATION ..................................................................................................................... 22

2.42 LABELS AND IDENTIFICATION ......................................................................................................... 23

2.43 CONTROLS ......................................................................................................................................... 24

2.44 DRY RISER ......................................................................................................................................... 30

2.45 DRAINAGE .......................................................................................................................................... 31

2.46 CHLORINATION AND WATER SAMPLING ....................................................................................... 36

2.47 BOILER DOSING EQUIPMENT.......................................................................................................... 37

2.48 FLUSHING OUT .................................................................................................................................. 37

2.49 COMMISSIONING .............................................................................................................................. 37

2.50 COMBUSTION EFFICIENCY TESTS ................................................................................................. 37

2.51 SYSTEM PERFORMANCE TESTS – HEATING SYSTEMS ............................................................. 38

2.52 SYSTEM PERFORMANCE TESTS – HOT AND COLD WATER SERVICES ................................... 39

2.53 SYSTEM PERFORMANCE TESTS – GAS SYSTEMS ...................................................................... 39

2.54 SYSTEM PERFORMANCE TESTS – VENTILATION SYSTEMS ...................................................... 40

2.55 SYSTEM PERFORMANCE TESTS – CONTROL SYSTEMS ............................................................ 40

2.56 SYSTEM PERFORMANCE TESTS – REFRIGERATION SYSTEMS ................................................ 40

2.57 THERMAL MODELLING ..................................................................................................................... 41

2.58 GENERAL DUCTWORK ..................................................................................................................... 41

2.59 DISTRIBUTION DUCTWORK ............................................................................................................. 41

2.60 DUCTWORK ....................................................................................................................................... 42

2.61 CLEANING/ACCESS DOORS ............................................................................................................ 43

2.62 DAMPERS (AIR HANDLING PLANT) ................................................................................................. 43

2.63 DUCT MOUNTED DAMPERS ............................................................................................................ 44

2.64 TERMINAL DAMPERS ....................................................................................................................... 45

2.65 FIRE/SMOKE DAMPERS ................................................................................................................... 45

2.66 ATTENUATORS .................................................................................................................................. 46

2.67 GRILLES AND DIFFUSERS ............................................................................................................... 46

2.68 WEATHER LOUVRES ........................................................................................................................ 46

2.69 AIR HANDLING UNITS AND FAN COIL UNITS ................................................................................. 47

2.70 FANS ................................................................................................................................................... 47

2.71 FLEXIBLE CONNECTIONS ................................................................................................................ 48

2.72 NOISE AND VIBRATION .................................................................................................................... 48

2.73 REFRIGERANT PIPEWORK AND FITTINGS .................................................................................... 49

2.74 EQUIPOTENTIAL BONDING .............................................................................................................. 51

2.75 MILLENNIUM COMPLIANCE ............................................................................................................. 52

2.76 OPERATING AND MAINTENANCE MANUAL ................................................................................... 52

2.77 RECORD DRAWINGS ........................................................................................................................ 53

Z:\WP\DMP\JOB\DMP\6658\Spec\F Section 2 Standard Mechanical.docx 1

2. SECTION TWO

STANDARDS OF MATERIALS AND WORKMANSHIP – MECHANICAL

2.1 STANDARDS

This standard specification is to be read in conjunction with the relevant particular

specification and preliminaries.

All installation work executed shall be carried out in accordance with the various

manufacturers’ recommendations and requirements, and shall comply with the following

statutory instruments, regulations, recommendations and bodies, as applicable:

a. British Standards Institute Specifications and/or Codes of Practice and/or British Board of Agreement Certification.

b. The requirements of Statutory Bodies.

c. The British Gas Safety Regulations.

d. The recommendations of the Chartered Institution of Building Services Engineers and Institute of Plumbing.

e. The recommendations of the local Fire and Emergency Planning Authority.

f. The Health and Safety Executive.

g. The Environmental Health Officer and all the COSHH requirements.

h. Requirements of the local Water Authority and the water regulations.

i. Requirements of British Gas.

j. Department of communities and local Government (Building Regulations).

k. Department of Energy.

l. N.H.B.R.C and NHBC requirements.

m. Acts of Parliament.

n. The Control of Asbestos Regulations 2012 and Approved Codes of Practice and Guidance L127 and L143.

o. Approved code of practice and guidance L8 2000 the control of legionella bacteria in water systems.

2.2 MATERIALS AND WORKMANSHIP (STANDARDS)

All materials supplied and work carried out shall be the best of their respective kinds and to

the approval of the Contract Administrator, who shall be at liberty to order the removal and

replacement of any faulty materials or inferior workmanship at no extra costs.

The Contractor shall employ fully skilled specialist craftsmen on the works.

All materials shall be new, and care shall be exercised to ensure that materials shall be kept

in that condition, proper storage facilities being used to fulfil this condition.

All materials or parts supplied, or work carried out, shall comply with the British Standards

where available. All gas burning appliances shall be approved by the British Gas

Corporation.

All domestic services pipework shall be installed to the Standards required by the Local

Water Authority.


2.3 MANUFACTURERS FINISH

All equipment supplied and installed shall, on completion, retain, undamaged, the

manufacturers finish. All damage shall be made good to the Contract Administrator's

complete satisfaction.

2.4 ACCESSIBILITY

For the purposes of this Specification, the word "accessible" shall apply to a space, duct,

chase or any other location in which pipework, valves, fittings or plant are to be located. It

shall also apply to pipework, valves, fittings or plant, if they will be concealed from view but

can be exposed fully by removing purpose made coverings or doors.

It shall also apply to ducts or crawlways into which it is possible to gain access through

manholes or trap doors and having gained access there is sufficient space in which to work

and dismantle and, if necessary, remove the equipment.

It shall also apply to plantroom equipment, i.e. tank rooms, boiler rooms, machine rooms,

pump rooms, etc., or any equipment where access is required to carry out routine

maintenance and/or equipment removal in a safe manner.

Any duct, chase or any other location which lacks these facilities shall for the purpose of this

Specification be regarded as inaccessible.

2.5 PIPEWORK AND FITTINGS

No joints shall be made in the thickness of walls and floors.

All pipework shall be installed in a neat workmanlike manner, arranged parallel to or at right

angles to structural members of the building and shall fit with the work of other services. All

pipe drops shall be plumb or parallel with adjacent surfaces.

Piping shall be installed so that there is a minimum clearance of 75 mm between the pipe

and the floor and shall be at clip distance from the wall surfaces.

Care shall be taken to prevent dirt entering pipes during installation, open ends of pipes shall

be crimped or provided with plastic caps and all valves shall be plugged.

The ends of all pipes are to be reamed to the full bore of the pipe. The removal of any

random piece of pipework may be required by the Contract Administrator to ensure that

reaming has been carried out. If such examination proves that reaming has not been carried

out the Contract Administrator may have such pipework as he considers necessary

dismantled and reassembled in a proper and workmanlike manner.

No extra cost will be allowed in respect of any bad workmanship, but if the examination

proves to be satisfactory, the Employer will pay for the work.

Branch connections from mains are to be so arranged that expansion and contraction may

take place without distortion either to the mains or branches.

Where pipes reduce in diameter, reducing sockets are to be used, due allowance being

made for air venting and draining of the installation.

All fittings on the cold water main above and below ground, internal or external, are to have

"lead free" solder.

All flux used for jointing is to be applied in a correct and proper manner. Flux shall be water

soluble and Water Research Centre approved.


Self cleaning fluxes are not to be used. Evidence of the use of excessive flux will result in

the Contract Administrator insisting on the removal of such pipework and its replacement.

Any resulting damage from flux corrosion will be deemed the Contractor's responsibility and

he will be held liable for any subsequent failures and all resulting damage.

All made and set bends are to have as large a radius as practicable and are to be free of

buckling or any form of restriction to the bore. All such bends are to be made with the aid of

a bending machine with all appropriate formers and guides.

Screwed pipe fittings are to be of malleable iron to B.S. 143 and 1256:2000 as applicable.

2.6 RUN OF PIPEWORK

The run of pipework is to be arranged in a neat and workmanlike manner. All sets or special

fittings are to be included for in:

a. Flow and return branches to radiators and heat emitters (note flow’s into radiators and emitter’s to be on same side through the project).

b. Vertical pipework where walls reduced in thickness.

c. Pipes that pass over joists, mouldings, casings, etc., beyond the face of the outer or inner walls and partitions.

d. All necessary setting and bending of pipework including any extra length of pipe and fittings, due to realignment of pipework necessitated by the position of any other services.

Pipework is to be laid to proper graded falls adequately supported with provision for expansion and suitably spaced to accommodate thermal insulation if required.

All pipework installed within floor ducts, screeds of the building structure is to be without

joints, except where agreed with the Contract Administrator and installed in such a way as to

permit subsequent access for maintenance or removal without disturbing adjacent pipework.

Vertical pipes are to drop parallel to walls, partitions and/or building structure, and flows and

returns are to run parallel to each other. Horizontal pipes are to be graded to clear air at

vent points or radiators and to drain at low points. Where uninsulated pipes run parallel to

one another, a distance of 25 mm is to be allowed between their respective surfaces. All

pipework must be fixed and hydraulically tested before the application of paint or thermal

insulation.

Pipework is not to be installed closer than 150 mm from any electrical cable, except where

cables are encased within P.V.C. mini trunking or at crossover points. In these instances,

purpose made fittings shall be installed.

Wherever possible, crossover points are to be avoided, but it is the responsibility of the

Contractor to ensure that any crossover points with electrical conduit/cable are adequately

insulated one from the other, by the Contractor, to the satisfaction of the Contract

Administrator. An air gap of at least 6 mm is to be left between the two surfaces.

In pitched roof spaces no pipes shall be installed within 1500 mm of the eaves.

The Contractor shall ensure that noise and vibration is eliminated from the installation.

Where pipework is in contact with floor or ceiling joists, a felt pad shall be provided. Animal

based felt shall not be used.

2.7 PIPEWORK

All open ends of pipe work left during construction shall be temporarily sealed with plugs to

prevent foreign matter entering the system.


a. Steel Pipework for Low Pressure Hot Water Heating Systems:

Steel pipework for use in low pressure hot water heating systems shall be of heavy gauge quality manufactured in accordance with the provisions of BSEN 10255:2004 and amendments.

Pipework shall be screwed, flanged or welded as detailed in the Sections of the Specification dealing with low pressure hot water.

All bends and tees shall be easy sweep pattern. Elbows, square tees and bushed fittings will not be permitted.

Fittings shall be best quality malleable iron, beaded or banded and easy sweep pattern. Flat seated unions shall not be used, unions shall have bronze conical seats ground in.

Fittings shall be manufactured in accordance with the provisions of B.S. 143:2000 and amendments.

White heart fittings manufactured in accordance with B.S. 1256:2000 and amendments may also be used.

All steel pipework over 50 mm diameter shall be welded unless stated otherwise.

b. Copper Pipe work for Low Pressure Hot Water Heating:

Copper pipe work for use in low pressure hot water heating systems shall be manufactured in accordance with E.N. 1057:1996 Part 1, it shall be half hard tempered to R250 and installed by kite mark licensee operating under BSI registered firm scheme in accordance with ISO 9001, fittings shall be to BSEN 1254 and bear the Kite mark.

Fittings shall be manufactured in accordance with E.N. 1254:1998 Parts 1 and 2 and amendments. Copper capillary fittings shall have integral solder ring and be Kite marked.

The use of self cleaning fluxes will not be allowed.

c. Copper Pipe work for Hot and Cold Water Services:

Copper pipework for use in hot and cold services shall be manufactured in accordance with E.N. 1057:1996 Part 1, it shall be half hard tempered to R250 and installed by kite mark licensee operating under BSI registered firm scheme in accordance with ISO 9001, fittings shall be to BSEN 1254 and bear the Kite mark.

Fittings shall be manufactured in accordance with E.N. 1254:1998, Parts 1 and 2 and amendments. Copper capillary fittings shall have integral solder ring and be Kite marked.


Copper capillary fittings on potable water services (i.e. mains cold water) shall have a lead free integral solder ring and be manufactured by "Yorkshire Imperial Fittings".

d. Galvanised pipe work for hot and cold water services:

Galvanised tube shall be heavy grade quality manufactured in accordance with the provisions of BSEN 10255:2004 and amendments. It shall be galvanised after manufacture.

Pipe work shall be screwed or flanged as detailed in the Sections of the Specification dealing with hot and cold water services. All fittings shall be best quality malleable iron galvanised after manufacture, fittings shall be manufactured in accordance with the provisions of BS EN10242: 1995 (ISO49) and amendments.

All bends and tees shall be easy sweep pattern. Elbows, square tees and bushed fittings will not be permitted.

Flat seated unions shall not be used; unions shall have bronze conical seats ground in.

Fittings shall be manufactured in accordance with the provisions of B.S. 143:2000 and amendments.


e. Steel Pipe work for Gas Services:

Steel pipework for internal gas services shall be medium grade quality manufactured in accordance with the provisions of BSEN 10255:2004 and amendments.

Pipework shall be screwed. All fittings shall be best quality malleable iron.

Flat seated unions shall not be used. Unions shall have bronze conical seats ground in. Fittings shall be manufactured in accordance with the provisions of B.S. 143:2000 and amendments. White heart fittings, manufactured in accordance with B.S. 1256:2000 and amendments, may also be used. All bends and tees shall be square pattern. Bushed fittings will not be permitted.

Screwed joints shall be made with Hawk White jointing paste.

External gas services shall be run in heavy quality steel to BSEN10255:2004 and amendments with screwed fittings as above. All external gas piping laid in the earth shall be carried out in yellow polythene tube with electrofusion welded fittings and laid to a minimum depth of 600 mm.

f. Copper Pipe work for Gas Services:

Copper pipe work for use in gas services shall be manufactured in accordance with E.N. 1057:1996 Part 1, it shall be half hard tempered to R250 and installed by kite mark licensee operating under BSI registered firm scheme in accordance with ISO 9001, fittings shall be to BSEN 1254 and bear the Kite mark.

Fittings shall be manufactured in accordance with E.N. 1254:1998 Parts 1 and 2 and amendments. Copper capillary fittings shall have integral solder ring and be Kite marked.


g. MDPE pipe work for Gas services Underground :

External underground gas mains distribution shall be carried out in polyethylene pipe in accordance with British gas specification GBE/PL2 parts 1 to 6 MDPE yellow, unless shown otherwise on the drawings. Joints shall be made with Electro fusion or butt fusion fittings as Wavin electro fusion (Wavin Plastics Limited Meadowfield Industrial Estate Meadowfield Brandon Co Durham DH7 8RJ) fittings, or equal and approved.

All installation and jointing shall be in accordance with the manufacturers requirements and recommendations.

The pipework shall be laid with a minimum depth to crown of pipe of 750mm (for carriageways and 600mm for footpath and verges) and no deeper than 1350mm. If minimum depth can not be achieved then protection is required in the form of a concrete raft placed above a cushion of gravel fill or similar method.

Trench width should be as narrow as practical and is usually not less than pipe diameter plus 250mm to enable full compaction of the side-fill. In most situations an imported bed and backfill material should be used. Acceptable bedding material includes pea gravel, washed sharp sand or crushed stone smaller than 20mm or sand/gravel mix.

Back fill in carriageway should follow local reinstatement specifications. Heavy mechanical compaction equipment should not be used until the fill over the pipe is at least 300mm.

h. Plastic pipe work for heating, hot and cold water services:

Plastic polybutylene pipework for use on heating, hot and cold services shall be manufactured in accordance with BS 7291 Parts 1 and 2 class S, with standard pipe for use on hot and cold water systems, and barrier pipe used for heating systems.

Fittings shall be integral push-fit mechanisium type Hep20 as manufactured by "Hepworth plumbing products".

For mains water above ground distribution can also be carried out co-extruded polyethylene barrier pipe in accordance with BS 6370 MDPE Black.

Joints shall be made with mechanical screwed compression fittings as Protecta-line Acetal (GPS pe pipe systems, St Peter’s Road, Huntingdon, Cambs, PE29 7DA),


screw compression fittings, or equal and approved. Underground polythene pipework shall be carefully laid in accordance with Local Water Authority Regulations.

i. Copper Pipe work for Buried Water Mains:

Copper pipework for external underground installations up to and including 54 mm shall be manufactured in accordance with the provisions of BSEN 12449:1999 Table Y kite marked, and double wrapped in acid resisting "Denso" tape.

All fittings shall be non-dezincifiable manipulative compression type to BSEN 1254:1998 as "Kuterlite" manufactured by Yorkshire Imperial Metals Ltd or equal and approved.

The pipe work shall be laid on a bed of, and surrounded with free draining coarse sand to give at least 100 mm cover all round. Backfilling shall then commence with a 350 mm depth of selected fine material free from all builders rubble, flints, stones, tree roots, etc., carefully hand packed.

Material shall not be dropped into the trench from a great height. Backfilling shall continue in layers not exceeding 350 mm in depth, well rammed and consolidated. Mechanical ramming shall not be used within 915 mm of the top of the pipe.

j. Polyethylene Pipe work for Buried Water Mains:

Up to and including 63 mm Nominal Bore:

External underground cold water mains distribution shall be carried out in co-extruded polyethylene barrier pipe in accordance with B.S. 6572:1985 MDPE blue with Protecta-line fittings, unless shown otherwise on the drawings. Joints shall be made with mechanical screwed compression fittings as Protecta-line Acetal (GPS pe pipe systems, St Peter’s Road, Huntingdon, Cambs, PE29 7DA), screw compression fittings, or equal and approved. Underground polythene pipework shall be carefully laid in accordance with Local Water Authority Regulations.

Above 63 mm Nominal Bore:

External underground cold water mains distribution shall be carried out in co-extruded polyethylene barrier pipe in accordance with BS 6730:1986, MDPE blue, unless shown otherwise on the drawings. Joints shall be made with Electro fusion or butt fusion fittings as Protecta-line (GPS pe pipe systems, St Peter’s Road, Huntingdon, Cambs, PE29 7DA), fluid compression fittings, or equal and approved. All installation and jointing shall be in accordance with the manufacturers requirements and recommendations, and those of the Local Water Authority.

The pipework shall be laid on a bed of, and surrounded with, free draining coarse sand to give at least 100 mm cover all round. Backfilling shall then commence with 350 mm depth of selected fine material free from all builders rubble, flints, stones, tree roots, etc., carefully hand packed. Material shall not be dropped into the trench from a great height.

Backfilling shall continue in layers not exceeding 350 mm in depth, well rammed and consolidated.

Mechanical ramming shall not be used within 915 mm of the top of the pipe.

k. Polyethylene Pipe work for Above ground Mains:

Up to and including 63 mm Nominal Bore:

External underground cold water mains distribution shall be carried out in co-extruded polyethylene barrier pipe in accordance with B.S. 6572:1985 MDPE black with protecta-line fittings, unless shown otherwise on the drawings. Joints shall be made with mechanical screwed compression fittings as Protecta-line Acetal (GPS pe pipe systems, St Peter’s Road, Huntingdon, Cambs, PE29 7DA), screw compression fittings, or equal and approved. Underground polythene pipework shall be carefully laid in accordance with Local Water Authority Regulations.

Above 63 mm Nominal Bore:

External underground cold water mains distribution shall be carried out in co-extruded polyethylene barrier pipe in accordance with BS 6730:1986, MDPE black, unless shown otherwise on the drawings. Joints shall be made with Electro fusion or butt fusion fittings as Protecta-line (GPS pe pipe systems, St Peter’s Road, Huntingdon,


Cambs, PE29 7DA), fluid compression fittings, or equal and approved. All installation and jointing shall be in accordance with the manufacturers requirements and recommendations, and those of the Local Water Authority.

The pipework shall be laid on a bed of, and surrounded with, free draining coarse sand to give at least 100 mm cover all round. Backfilling shall then commence with 350 mm depth of selected fine material free from all builders rubble, flints, stones, tree roots, etc., carefully hand packed. Material shall not be dropped into the trench from a great height.

Backfilling shall continue in layers not exceeding 350 mm in depth, well rammed and consolidated.

Mechanical ramming shall not be used within 915 mm of the top of the pipe.

2.8 SCREWED PIPE JOINTING

Where it is specified that the pipework shall be joined together by screwing, the Contractor

shall comply with the following instructions:-

Screwed Joints on Steel Piping:

Screwed joints shall be made in accordance with the provisions of B.S. 21:1985 and shall be

close threaded, pulled up tightly and made with approved jointing compound and long strand

hemp.

After joints have been formed all surplus hemp shall be cut away and joint wiped clean.

All reducing sockets shall be eccentric and arranged for drainage and/or venting.

All cuts from standard lengths shall be all burrs and swarf removed and the ends of the pipes

shall be trimmed square.

Where pipes are held in vices, as when screwing, care shall be taken to ensure that the pipe

surface is not damaged. Any pipework so damaged shall not be fitted.

Where tube is galvanised care shall be taken to ensure that threads are carefully cut so that

the number of exposed threads is minimised.

Hemp shall not be used on steam, condensate, gas or oil piping.

2.9 FLANGED JOINTS

All flanges shall be manufactured from mild steel to B.S. 10:1962 and B.S. 4504 of that

Specification appropriate to the pressure involved.

Flanges shall be machine faced, trimmed at the edges and spot faced for nuts. Bolt holes

shall be drilled and not punched. Flanges on screwed work shall be screwed and

subsequently expanded.

Flanges for welding shall be slip-on type. The tube shall finish 3 mm inside the bore and a

sealing run shall be applied.

All flanged joints shall be flush and truly aligned and shall employ brass full faced Taylor's

corrugated rings coated on both sides with an approved jointing compound. Nuts, bolts and

washers shall be black mild steel or galvanised, as appropriate, and all bolts shall be of the

correct length. Taylor's rings must be properly aligned; damaged rings shall not be fitted.

2.10 WELDED PIPEWORK

Where it is specified that piping shall be jointed together by welding the Contractor shall

comply with the following instructions:-


Welded Steel Piping:

Pipework for welding shall be supplied with plain ends, bevelled for butt welding. All welding

joints shall be made by Oxyacetylene process and in accordance with B.S. 2640:1982 and

amendments, and the "Recommended Practice of Oxy-Acetylene Welds in Mild Steel Pipe

Lines" published by the Heating and Ventilating Contractors Association. Welding shall be

executed by welders holding a current Certificate of Competency, as required by the welding

institute.

All welded tees, branches, reducers, etc., shall have bevelled mitred joints and be finished

with a fillet weld of ample dimensions.

Seamless steel butt welding pipe fittings may be used. They shall be manufactured in

accordance with B.S. 1965 Parts 1 and 2:1964 and amendments, heavy grade.

Care shall be taken to ensure that welding metal or flux does not project into the bore of the

pipe.

All welds shall be of good clean metal free from slag and porosity, of even thickness and

contour, well fused with the parent metal, annealed and hammered on completion and

finished smooth.

The Contract Administrator reserves the right to have cut for examination up to 2% of all

welds made. The Contractor shall remake the joints at no extra charge.

All sets, double sets and springs shall be formed on long lengths of tube with as large a

radius as possible and shall be free from distortion.

Arc Welding:

The Contractor may wish to employ arc welding for the works or parts thereof.

If the Contractor desires to use arc welding he shall:

a. Notify the Contract Administrator at the time of tender and the Contract Administrator will ascertain whether it is possible for an electricity supply to be made available. In certain circumstances, eg. where the supply to a premises is subject to a maximum demand tariff it may be grossly inconvenient for the Employer to make a supply available and the Contractor may, rather than bear the cost, prefer to use portable generating equipment.

b. Obtain the Contract Administrator's permission at the time of tender.

c. Include for all charges for electric current and provide all cable and separate meters in his Tender.

d. Include for the provision of any generating equipment and its operation that may be needed.

Operatives employed on arc welding shall hold a current Certificate of Competency as

required by the welding institute.


2.11 ERECTION OF PIPEWORK

All pipework shall be erected with continuous gradients. The gradient shall be appropriate to

the service, and shall be as follows unless otherwise specified on the Drawings.

Service Gradient

Low pressure heating (mains) 25 mm in 12 m

Low pressure heating (branches) 25 mm in 6 m

Hot water service (mains) 25 mm in 12 m

Cold water 25 mm in 18 m

Hot water service (branches) 25 mm in 6 m

All piping shall be erected to present a neat and orderly appearance arranged parallel to or

at right angles to structural members of the building, and shall give maximum headroom, not

obstructing windows and doorways, and fitting in with the work of other Contractors. All pipe

drops shall be plumb. No joints shall be formed in the thickness of walls, floors or ceilings.

It shall be the responsibility of the Contractor to ascertain the thickness of plaster and other

wall finishes, skirting heights, cill heights and floor finishes. Pipework shall generally be set

around all piers and columns and shall follow the counter of the building whether so

indicated on the drawings or not.

Where visible, changes of direction shall be made with fittings in preference to pulled or

made bends, except where these are to accommodate expansion.

Piping shall be erected so that there is 75 mm clear below it to the finished floor level and at

least 25 mm to the finished wall face or clip distance as appropriate.

All pipework, valves, fittings and equipment forming the piping installation shall be erected so

that it can be dismantled and is accessible for repair and replacement.

Unions or flanges shall be provided at valves and equipment so that they can be dismantled,

and elsewhere as necessary to facilitate erection and disconnection. Flanges or unions shall

be provided on straight horizontal unobstructed runs at not greater than 12 m intervals.

Unions may be used for lines up to 50 mm diameter.

The Contractor shall make due allowance during erection for thermal insulation.

Bends, springs and off-sets shall be formed by use of an efficient bending machine or fire

sets. Fire sets shall not be employed on galvanised tube. Copper tube may have its bends,

springs and off-sets formed with springs.

All changes of direction so formed shall be made with a minimum loss of local wall thickness

and the diameter shall be maintained. Crinkled and scored work will be rejected. Cutting

and shutting will not be permitted.


2.12 PIPE SUPPORTS

All pipe work shall be supported by means of clips, hangers, etc., at the following centres:

Nominal Bore of Interval

Steel Pipe (mm) (metres)

Vertical Horizontal

15 2.4 2.0

20 2.4 2.4

25 3.0 2.7

32 3.0 2.7

40 4.5 3.0

50 4.5 3.4

65 4.5 3.7

80 6.0 3.7

100 6.0 4.1

125 6.0 4.4

150 6.0 4.8

200 6.0 5.1


PVC Pipe (mm) (metres)

Vertical Horizontal

15 1.3 0.7

20 1.4 0.7

25 1.6 0.8

32 1.7 0.9

40 1.9 1.0

50 2.2 1.1

65 2.8 1.4

100 3.1 1.6

150 3.7 1.9


MDPE BLK Pipe (mm) (metres)

Vertical Horizontal

20 0.9 0.5

25 1.2 0.6

32 1.2 0.6

50 1.5 0.8

65 1.6 0.8

Nominal Bore Of Interval (metres)

Copper Pipe (mm) Vertical Horizontal

15 1.8 1.4

22 1.8 1.4

28 2.0 1.7

35 2.0 1.7

42 3.0 2.0

54 3.0 2.0

67 3.6 2.0

76 3.6 2.4

108 3.6 2.7


133 3.6 3.0

159 3.9 3.4

In the event of two or more pipes being carried out by a single support the spacing shall be

for the shorter intervals.

Where copper or steel piping is at low level (floor) 15 mm and 22/20 mm diameter shall be

supported at 600 mm intervals and all other sizes up to 76/80 mm at 1800 mm centres.

All supports for mild steel pipes and fittings shall be ferrous. Within rooms, all brackets

supporting pipework shall be of school board pattern.

Soft pads shall be provided in all cases where there is a possibility of piping running against

woodwork or other materials to avoid the possibility of noise after the plant has been set to

work. Animal based felts shall not be used.

It shall be the responsibility of the Contractor to ensure that all supports are adequate, firmly

and truly fixed, and that they do not promote vibration. The Contractor shall report

inadequacies in this respect to the Contract Administrator. Services in the ground shall be

erected with care and in such a manner that pipework and fittings shall not be damaged due

to movement of the ground. Where pipes pass under roadways carrying vehicles they shall

be fitted inside sleeves or conduits.

Where piping is to be supported under concrete, construction inserts for this purpose shall

be provided and shall be placed in the formwork before concrete is poured. Inserts shall be

of cast iron or mild steel of the type to receive bolts, heads or nuts after installation and shall

permit adjustment of the bolt in a horizontal direction.

All light gauge copper pipework is to be supported at a maximum distance of 600 mm

between supports with SCH nylon saddles, as manufactured by Arthur Fischer (U.K) Ltd,

Type 1216 SCH and 1623 SCH, or equal and approved manufacture. These are to be

screwed to the walls, partitions, etc., with brass screws.

Where multiple pipe clips are necessary sufficient screws must be inserted to provide

adequate support.

The final fixing shall be to the approval of the Contract Administrator. SCH nylon saddles

are not to be used where pipework is insulated. Brass single ring clips/skirting clips shall be

used to provide a suitable space to allow the installation of the specified pipe insulation.

Brackets or supports shall be set out so that they do not obstruct the access to valves, flange

or other fittings requiring maintenance.

Supports to chilled water pipework shall include for spacer blocks to provide vapour seal

continuity with the thermal insulation material.

These blocks shall be either two piece wooden blocks or crocodile segmented wooden or

plastic blocks. Pipe fixings/saddles to be fitted to the outside of the blocks.

2.13 PIPE SLEEVES

Where pipes pass through walls, floors, footings and waterproofed membranes, the

Contractor shall provide sleeves. Sleeves shall be correctly positioned and built in.

The inside diameter of sleeves shall not be less than 15 mm larger than the outside diameter

of the pipe, except where pipes pass through bearing walls or footings where sleeves shall

be 100 mm larger than the outside diameter of the pipe and sealed after installation.

Sleeves in bearing walls or footings shall be cast iron pipe.


Sleeves in walls, floors, ceilings and partitions shall be of the same metal as the pipe.

Sleeves of other materials will be permitted provided that they are inert and approved by the

Architect.

Sleeves shall terminate flush with the finished surface.

Flashing sleeves shall be provided by the Contractor where pipes pass through

waterproofing membranes. Flashing sleeves shall be provided with an integral flange to

which a flashing shield can be clamped or welded. The shields shall be in zinc and shall

extend not less than 200 mm from the sleeves in all directions. The Contractor shall make

the shield into the membrane and shall fill the space between the sleeve and pipe with

waterproof material and mastic.

2.14 WALL AND FLOOR PLATES

Where pipes pass through floors, ceilings and pre-finished partitions, etc., they shall be fitted

with chromium plated wall or floor plates. The Contractor shall space his pipes to allow the

fitting of full plates where possible, but if cases of overlapping plates occur then both plates

shall be cut to give a uniform appearance.

2.15 TESTING PIPEWORK

All pipework, fittings, plant and equipment shall be tested hydraulically to a pressure

equivalent to one and a half times the working pressure or 3.5 bars whichever is the greater.

After the pressure is obtained the test rig shall be disconnected and the pressure shall

remain constant for two hours. During this period all welds on steel pipe shall be well

hammered.

Water services pipes must withstand the working pressure with all draw off taps closed,

without showing any leakage, sweating or other defects.

All gas pipework shall be air tested on completion or in sections as may be required during

progress of the works, by installer with relevant gas safety certification.

The Contractor is to provide the necessary instruments, materials and attendance for

preparing prior to, during and after tests.

The Contractor shall make good any leaks or other defects, re-test and leave the system

completely satisfactory.

All tests shall be witnessed by the Contract Administrator or such other persons who shall be

nominated to witness the tests. No pipework shall be insulated or concealed until the test

has been witnessed and passed.

Test certificates are obligatory and shall be provided for the Contract Administrator

signature.

The Contractor shall allow in his tender for testing the installations in whole or in part as

necessary to facilitate the progress of works by other trades or to enable the works to be

commissioned in sections. No extras shall be allowed.

All test certificates shall be incorporated into the relevant section of the finalised operation

and maintenance manual.

2.16 STORAGE OF PIPEWORK

All tubes stored on site shall be kept clear of the ground and where possible they shall be

stored under cover.


Screwed ends of tubes shall be protected with a socket, half socket or plastic thimble.

Tubes must be examined internally before and after cutting and any foreign matter must be

removed.

Stocks of tube remaining on site for long periods must be periodically inspected and tube

corroded beyond normal "stock rust" condition shall not be used. The Contract Administrator

will instruct the Contractor to remove tube in poor condition from the site whether fixed or not

and no extra will be allowed in any circumstances whatsoever.

2.17 PREVENTION OF DIRT ENTERING PIPE, VALVES, ETC

The Contractor shall guarantee that all tubes, valves, fittings, etc., are free from corrosion

and internal obstruction. Pipework showing signs of corrosion shall not be fitted.

Special care shall be taken to prevent dirt and rubbish entering the open ends of pipes prior

to, during and after erection. Wrought iron screwed caps or plugs, or plastic covers only

shall be used. Wood, rag or paper plugs shall not be used.

Failure to comply with this instruction shall mean that the Contract Administrator shall have

the right to order the pipework to be dismantled for as far as considered necessary and the

pipework to be cleaned internally. Such work shall be carried out at no cost to the Employer.

The Contractor is reminded that a valve fitted to the open end of a disconnected pipe is not

considered satisfactory to prevent the entry of rubbish. The open end shall be capped,

plugged or crimped.

2.18 EXPANSION

Wherever possible, provision for expansion and contraction of piping is made by changes in

direction and the Contractor is to take full advantage of this during installation, applying

"Cold draw" if necessary. In other cases, adequate expansion loops or expansion fittings

shall be provided.

Expansion loops when required shall be formed with welded bends. The loops shall be shop

manufactured and annealed after welding. Connections to the mains shall be with flanges.

Each leg of the loop shall be pulled cold to approximately 50% of the estimated expansion

on each leg. This cold draw shall be pulled by means of long bolts through the flanges.

Bolts shall be pulled up diagonally to prevent uneven stressing and after the flanges are tight

the bolts shall be replaced one by one with bolts of the correct length.

During the cold draw process the Contract Administrator shall be present to witness the

operation. It is the Contractor's responsibility to give the Contract Administrator adequate

notice.

2.19 ANCHORS AND GUIDES

Pipe anchors shall consist of heavy steel collars with lugs and bolts for clamping and for

attaching to anchor braces or as detailed on the Drawings. Anchor braces shall be installed

in the most effective manner to obtain the required bracing. No anchor braces shall be

attached in locations where their installation will result in damage to the building

construction. Details of anchors shall be submitted to the Contract Administrator for

approval before installation.

Guides shall be provided independent of anchors and expansion joints to prevent buckling.

They shall be located at 600 mm either side of expansion loops or fittings and at the mid

point between fittings and loops.

Where specifically required anchors and guides are noted on the drawings.


2.20 VALVES AND COCKS

All valves and cocks for heating, hot water and cold water shall comply with the requirements

of the appropriate Water Authority and the Contractor shall include for any testing and

stamping which the Authority shall require.

Gas valves and cocks shall comply with the appropriate Gas Authority requirements.

All valves and cocks shall be located in such a position that they can be readily operated for

maintenance. No valve or cock shall be installed in such a position that it cannot be

removed for repairs.

The Contractor shall at the time of the Tender point out to the Contract Administrator any

discrepancy between a manufacturers type or figure number and that scheduled by the

Contract Administrator, and which in the Contractor's opinion is incorrect.

Valves and cocks shall be supplied to the following detail unless specified to the contrary in

the following sections:

Heating Circuits and Chilled Water Circuits:

SERVICE OVENTROP HATTERSLEY CRANE T.A HERZ

Isolation:

50mm and below 107 90 100 D171A TA85 K-KV

65mm and over 104 80 970 F624 TA36 BF-FLL

Regulation/Commissioning Commissioning Valves:

50mm and below 106 08 CV2432 D931 MD41 4217CS

65mm and over 106 28 CVM 2733 PN16 DM940 MDF4 4218CS

Low flow:

50mm and below 106 11 64 1473 D933/D934 (D922)

MD22 -

Medium flow:

50mm and below 106 06 34 100M - MD03 -

Regulation Values:

50m and below 106 01 1432 D920 MD20 4217

65mm and over 106 26 M733DR DM920 MDF4 4218

Orifice Values:

50mm and below 106 06 1000 D901 MD01 4000

65mm and over 106 07 M2000 PN16 DM900 MDF0 HV2740


Hot and Cold Water Circuits and Distribution:

SERVICE OVENTROP HATTERSLEY CRANE T.A HERZ

Isolation:

50mm and below 104 30 33X 151 TA64

65mm and over 104 80 370 F624 TA36

Or

50mm and below 107 95 100C D171C TA85C

65mm and over 107 90 100 D171A TA85

Regulation/Commissioning Commissioning Valves:

50mm and below 106 08 CV2432 D931 MD41 4217DZR + 4000

65mm and over 106 28 CVM2733 PN16 DM940 MDF4 4218 + 2740

Regulation Values:

50m and below 106 01 1432 D920 MD20 4217DZR

65mm and over 106 26 M733DR DM920 MDF2 4218

Orifice Sets:

50mm and below 106 06 1000 D901 MD01 4000

65mm and over 106 07 M2000 DM900 MDF0 HV2740

Hot and Cold Water branches:

Gunmetal screwdown stopcocks to B.S. 1010 with crutch handles. (Easy clean pattern).

Additionally, a service valve shall be fitted to every float valve or W.W.P's as above.

Failsafe Blending Valves:-

Herz Oventrop Horne

Fig

15mm: Hertzshield 130 03 TMV15

22mm: Hertzshield 130 03 TMV120


Radiator Valves:

Valves on connections to radiators and convectors shall be of the wheelhead or thermostatic

type on the flow and lockshield pattern on the return, as detailed later in the Specification.

Type Crane Oventrop Herz

Angle:

W/H D880 119 00 DR-T- 90 or GP

L/S D881 109 06 RL-I or RL-5

Straight:

W/H D890 119 01 DR-T -90 or GP

L/S D891 109 07 RL-I or RL-5

Thermostatic Radiator Valves:

Where thermostatic radiator valves are specified they shall have standard bodies, chromium

plated and shall be installed in accordance with the manufacturers recommendations, but

after heating circulation tests and balancing, during which thermostatic heads shall be

removed

Type Crane Oventrop Danfoss Herz

Angle D882CP 118 37 RA - N TS-90

Straight - 118 38 TS-98V

Heads 1018561 RA2000 Range 9230/9430 range

Convector and Fan Coil Valves:

Valves on connections to convectors or fan coil units shall be straight pattern wheelhead on

flow connection and straight pattern lockshield on return connection.

Crane Oventrop Herz

D171 Ball Valve 107 90 K-KV

107 95

D171 L/S Ball Valve 107 92 DR-T-90

107 99

Gas Cocks:

Newman-Milliken Lubricated Plug Cocks, Fig. No. 200M and 201M.

Oventrop: Up to 50mm 301 64

65mm and above 104 81


Underground Stopcock:

These to be fitted to polythene tube to be Yorkshire Fig. 771 GM.

For pipe work with flanges 65mm and above Crane F52 Cast iron gate valve

2.21 VALVE KEYS

The Contractor shall mount on a polished boards fixed in the plant rooms any specialised

valve keys necessary for the maintenance and adjustment of the equipment installed.

2.22 AUTOMATIC AIR VENTS

Where automatic air vents are shown on the Drawings and elsewhere as necessary they

shall be of Charles Winn manufacture or Oventrop Fig. 108 32. In all cases the air vent shall

be preceded by a lockshield pattern stop valve and the discharge from the air vent shall be

12 mm copper pipe which shall discharge over a gully, sump or other convenient position

which shall be agreed with the contracts administrator.

The float and valve mechanisms shall be suitable for use with hot water.

Oventrop 108 82 03

2.23 AIR COCKS AND BOTTLES

Air vents shall be fitted to all high points of the heating and hot water services.

All radiators, convectors and all pipework which requires venting shall be fitted with 6 mm air

cocks unless otherwise specified.

Air bottles where shown on the drawings and elsewhere as necessary, are to be formed

from:-

a. 150 mm length of tube of equal bore to the pipe being vented, on pipework up to and including 50 mm diameter.

b. 50 mm diameter tube of a length equal to 150 mm plus one diameter of the pipe being vented on pipework exceeding 50 mm diameter.

All air bottles shall have a 6 mm pipe welded into the top and taken to low level and fitted

with a 6 mm lockshield needle valve as Hattersley Fig. 5N and plugged.

The Contractor shall fit these items so that they are readily accessible.

Open vents shall be vertical or where it is necessary for them to travel horizontally they shall

rise continuously.

2.24 DRAIN COCKS

Drain cocks shall be fitted on boilers, hot water cylinders and on all low points of the heating,

hot and cold water services, and on the 'dead' side of all isolating valves and cocks whether

shown on the Drawings or not.

Drain cocks shall be of gunmetal with screwed ends to B.S. 2879:1980.

Hattersley Fig 371 lock shield pattern or

Oventrop: Plantrooms - 103 33

General use - 103 35


They shall be positioned as unobtrusively as possible. If a drain cock must inevitably be

positioned where it may prove a danger or nuisance, one elbow shall be fitted so that the

drain cock lies parallel to the pipe being drained and hence is protected by it.

For boilers, calorifiers, cylinders and cisterns the following sizes shall be used:-

20 mm diameter for boilers of up to 8 sq. m heating surface and for calorifiers, cylinders, and

cisterns up to 900 litres capacity.

25 mm diameter for boilers over 8 sq. m and calorifiers, cylinders and cisterns above 900

litre capacity.

2.25 PRESSURE GAUGES

Pressure gauges shall be provided on boilers, pump sets and elsewhere where specified, or

shown on Drawings. Gauges shall be N.A.B.I.C. Fig. No. 62, brass cased, 100 mm

diameter. Gauges shall be graduated metres head and in bars and N/m² from zero to twice

normal working pressure of the system. The normal cold fill pressure shall be indicated by a

red pointer. Each gauge shall be provided with a brass siphon tube and lever handled

isolating cock.

Where gauges are remotely located they shall be complete with the necessary tubing neatly

fixed. Remote gauges shall be grouped and mounted on a black enamelled steel panel with

identification labels.

2.26 THERMOMETERS

Thermometers shall be dial pattern, 100 mm dia. and of N.A.B.I.C. manufacture. Each

thermometer shall be provided with a pocket and oil filled well. Thermometers shall be fitted

in easily readable position inserted into pipe work to a sufficient depth to ensure accurate

readings are given

Thermometers shall be provided on boilers and elsewhere where specified, or shown on the

Drawings.

All thermometers shall be fixed so that the bulb is properly immersed.

Thermometers shall be graduated in °C from 0°C to 150°C.

2.27 BOILER SAFETY VALVE

Water safety valves of the totally enclosed type shall be fitted on each boiler and calorifier to

the sizes as specified by the equipment manufacturer.

The safety valves shall comply with BS EN ISO 4126-1 and shall be of Gunmetal

construction and spring loaded with a metal to metal seat. A padlock and key shall be

provided to each safety valve.

A full bore drip pipe shall be fitted from the outlet of each safety valve to carry any water

discharge clear of the appliance being protected and its insulation. This drip pipe shall

terminate with a square cut end 450mm from the floor in a safe, but in an easily visible

position preferable over a drain. Discharge pipes shall be copper on copper systems,

galvanised on all others.

Each valve shall be stamped to show the actual bore of the valve and shall be arranged so

that the valve can be rotated and lifted from its seat during the testing without unlocking and

set to blow at a minimum of plus 10% of plus 0.7 bar (whichever is greater) of working


pressure. However the set pressure of a safety valve must not exceed the design pressure

of the equipment or system being protected.

The safety valves shall be as manufactured by the NABIC Fig 542 for vented systems or Fig

500 for unvented systems.

Each valve shall be tested by the manufacturers and adjusted to the correct load before

despatch.

2.28 STRAINERS AND TEST POINTS

Strainers:

Pipeline strainers are to be installed in the return pipe work prior to any plant item or control

valve etc., on heating and chilled water and secondary hot water services.

Strainers are to be type Y strainers as:

Crane D297 up to 2” Brass or FM276 over 2” cast iron

Strainers located in Glycol filled system shall be suitable for operation with Glycol solution

and operating at sub-zero temperatures.

Test Points:

Test points shall be fitted on the suction and delivery side of each pump and where indicated

on the drawings. These shall be self-sealing ethylene propylene rubber test points as

manufacturer by Test Plugs Ltd.

The contractor shall allow for supplying upon completion to one site, one temperature and

one pressure test gauge to be handed over to the client on completion of works, also

available from Test Plugs Ltd.

2.29 WATER REGULATIONS

The complete installation is to comply in all respects with the Water Supply (Water Fittings)

Regulations 1999.

It is the Contractor’s responsibility to ensure that all work is carried out on water pipe work

etc., is in compliance with the “approved Plumber Scheme” and contractor must provide a

“Certificate of Compliance” to the water supply authority upon completion of each

appropriate section of work.

Should the Contractor have the work carried out by an “unapproved plumber”, and then the

Contractor must submit full details (i.e. drawings, material specification, method statement

etc.) to the water company at least 10 days prior to commencement of work. The Contractor

must submit the details to, the local Water Authority for the area.

2.30 LEGIONELLA CONTROL

The complete installation is to comply in all respects with the Health and safety

commissions, “Approved code of practice and guidance on the control of legionella bacteria

in water systems L8 2000”.

It is the Contractor’s responsibility to ensure that all persons carrying out work on water

system etc., are fully aware of these requirement and that all necessary works, testing,

commissioning, identification and assessment of risks are carried out.


2.31 SUPPORTING STRUCTURES AND BRACKETS

The Contractor shall supply, fabricate and fix all steel structures and brackets required for

the support of plant, equipment and services. All such structures are to be constructed of

rolled steel sections or similar, of adequate cross section and strength, bolted or welded

together and painted two coats of red oxide primer. The Contractor shall provide for

approval details of the design of all such structures.

Structures shall, wherever possible, be entirely self-supporting and suitable for bolting to the

floor of the building.

Welding or bolting of supports to structural steelwork will not be permitted unless authorised

by the Contract Administrator in writing.

2.32 SPARES AND TOOLS

The Contractor shall mount on a polished hardwood board fixed in the plant room any

specialised tools necessary for the maintenance and adjustment of the equipment installed.

Provide all necessary spares for motors (belts etc.), ductwork system (Filters etc.) and all

major items of plant etc.

2.33 GUARDS TO PROTECT PLANT

All wire guards, handrails and other approved types of guards or gates necessary to protect

any of the plant or equipment in accordance with the requirements of the Health and Safety

Executive shall be provided by the Contractor.

2.34 LUBRICATION

All bearings, glands and other items of plant and equipment shall be charged with the correct

grade of oil/grease as recommended by the manufacturers.

2.35 PREVENTION OF NOISE AND VIBRATION

The Contractor shall take every precaution needed to ensure that noise and vibration are

eliminated from the installations. He shall erect piping, ductwork, fans, plant and machinery

so that the assembled plants will be suitable for silent operation under the conditions in

which they operate.

He shall at the time of tendering draw to the Contract Administrator attention anything which,

in his opinion, will cause the system to operate other than silently.

It is the Contractor's responsibility to ensure that the sound level from installed plant is within

the design sound levels produced by the manufacturer which shall be submitted to the

Contract Administrator prior to ordering.

All running plant shall be provided with efficient anti-vibration mountings.

2.36 INCOMING WATER MAINS

Unless specified to the contrary, the Contractor will commence from the consumers side of

the main valves supplied by the Local Water Authority.

2.37 CISTERNS AND TANKS

All tanks are to be either:

One piece or sectional GRP plastic complete with purpose made thermal insulation, or


Galvanised where installed into existing system that has existing galvanised services pipe

work, with separate insulation added after installation

Water tanks supports are to be installed to requirements of the water regulation schedule 2,

section 7, and paragraph 16.

Above all supports are to be as required by the manufacturer.

All tanks are to be fitted with overflow and/or warning pipe work, as required by the Water

Regulations and are to terminate outside the building, all as detailed in Water Regulations

Schedule 2 Section 7 paragraph 16.

All tanks are to be fitted with potable water kits as Water Regulations Schedule 2, Section 7

paragraph 16 consisting of:

a. Effective adjustable valve capable of shutting off the inflow of water.

b. Service valve on water inlet pipe.

c. Service valve on all outlet pipes.

d. Overflow pipe (warning) which excludes insects.

e. Cover to exclude light and insects, with manhole and ladder as appropriate.

f. Thermal insulation to minimise freezing and undue warming of water.

g. Installed as to minimise risk of contamination of stored water, appropriately sized and connections positioned so as to allow free circulation and prevent areas of stagnant water.

All pipe work, within the tank room and where subject to frost damage shall be insulated.

The insulation, in general, on pipe work shall comply with Water Regulations/Bylaws,

Schedule 2 Section 3 paragraph 4, the relevant British Standards, Part L of the Building

Regulations and section 2.42 of this specification, however the minimum thickness used

within dwellings shall be 13 mm.

The provision for safe access to the tanks is given within the following publications that

should be referred to for their information.

a. Design And Maintenance Guide 08, Space Requirements For Plant Access, Operation And Maintenance, Defence Works Functional Standard, Ministry Of Defence.

b. Building Regulations Approved Document F, section 2.15 to 2.17.

2.38 OVERFLOW AND OTHER WARNING PIPES

Overflow and warning pipes shall be fitted so that they discharge in obvious positions.

Materials shall be mild steel galvanised or copper depending on the plant to which they are

fixed. Fittings shall be as appropriate.

Overflows shall be fitted with a continuous fall.

All compliant with the relevant sections of the Water Regulations.

2.39 PAINTING GALVANISED TANKS

The Contractor shall paint in its entirety galvanised cold water storage cisterns including all

ties and stays with three coats of a suitable bitumen based paint. The manufacturers

instructions covering the application of the paint and preparation of surfaces shall be closely

followed.


2.40 PREPARATION FOR PAINTING, PAINTING, CLEANING THE WORKS ON COMPLETION

At the completion of the works all parts of the installation shall be thoroughly cleaned. All

equipment, pipe, valves, fittings, etc., shall be cleaned of all grease, dirt, metal cuttings,

sludge, etc., which may have accumulated. Any discolouration or other damage to parts of

the building or its finish or furnishing due to the failure of the Contractor to properly clean the

equipment or piping system shall be repaired by the Contractor without additional cost to the

Employer.

The Contractor shall wire brush all black steel pipe work and exposed pipe threads and

apply two coats of red oxide paint as the pipe work is installed.

All gas pipe work to be final painted with two coats gloss (yellow ochre) to B.S. colour

08ES1.

2.41 THERMAL INSULATION

Pipework:

All water services pipe work shall be insulated where installed in unheated spaces or

underground ducts, voids, ducts or ceilings, etc., or where not forming useful heating

surfaces, or where condensation is likely to occur or where subject to frost damage as

follows:

All heating, hot or cold water pipe work, cold feeds and vents, etc., within voids, ceilings,

casings shall be insulated with fibreglass rigid sections with canvas and bands (at not more

than 600 mm intervals) and where exposed to water penetration be painted with two coats

P.V.A. emulsion.

Pipe work shall be erected with proper clearance between pipes to allow for the application

of insulation. No two pipes shall be lagged together unless prior approval.

Particular attention shall be paid to the appearance of the insulation with respect of joints,

bends, uniformity of thickness, finish, irregularities in appearance etc., and any work, which

is sub-standard, shall be removed and reinstated at the contractor’s expense.

Identification bands/colour coding and direction arrows, shall be provided on all services,

heating, hot and cold water pipe work in ducts, voids or ceilings to B.S. 1710:1984.

All heating, hot and cold pipe work within plant rooms/boiler rooms shall be insulated with

fibreglass rigid section, scrim covered, pasted and secured. The finish to all services shall

be minimum 0.35 mm thick Isofix P.V.C. covering complete with aluminium end caps at

brackets and valves, with preformed bends. All joints to be taped with matching grey self

adhesive tape with joints concealed from view as far as possible.

All valves, non return valves, strainers, etc., within plant rooms and where exposed outside

shall be insulated with removable "muff" covers.

All heating and hot water pipe work buried in floor screeds shall be coated with two layers

Denso P.P.S. tape.

All mains cold water pipe work exposed in rooms shall be insulated complete with all

necessary protection against condensation.

Where pipe work runs external to the building fabric it shall be insulated with class O

Armaflex by Armstrong Industries in accordance with the manufacturers instructions and

wrapped in polyisobutylene (PIB) weatherproof external finish sheeting. The PIB sheeting

shall be glued/welded as necessary and where the pipework enters the building, the


sheeting shall be splayed and adhered to the building surface to form a protected shroud

around the pipework entrance.

Pipe work insulation thickness physical characteristics and definitions shall be in accordance

with B.S. 5422:2001.

For domestic heating systems Armaflex class O preformed sectional insulation can be used,

with all joints sealed with adhesive, installed in accordance with manufacturers

recommendations and to the thickness detailed in BS5422:2001 and part L of the Building

Regulations.

All hot water cylinders, cold water and feed tanks where not pre-insulated shall be insulated

with fibreglass rigid slabs/foil faced wired on as appropriate minimum 75 mm thick.

Ductwork:

The Contractor shall supply and install thermal insulation to all ducts as described herein.

All distribution ductwork carrying air at a temperature higher or lower than the design room

temperatures (± 2°C) to prevent duct heat loss, duct heat gain, condensation, etc., shall be

thermally insulated. All ductwork (supply and extract) exposed externally shall be insulated.

Kitchen systems shall be insulated to the requirements of HVCA standard DW 172

Ducts in plantrooms and all recirculation systems - Fibreglass slab foiled backed min 25mm

thick

Ductwork in ceilings, voids, etc. - Fibreglass quilt foiled backed min 25mm thick

Ductwork exposed externally - Foil faced phenolic foam glued to duct with reinforced poly-

isobutylene outer finish, glued to phenolic foam min 25mm thick

Refrigeration Pipework:

Thermal insulation shall be applied to all condensate pipe work and all internal hot gas pipe

work as follows:

The internal Hot gas, condensate and external condensate pipe work shall be insulated with

"ARMAFLEX" Type '0' preformed sectional insulation with all joints sealed with adhesive,

installed in accordance with manufacturers recommendations, making sure that end joints

are puckered on application to allow for the contraction characteristics of the material. All

bends, tees, etc., to have oversize sections filled to ensure a continual vapour barrier.

External valves shall be fitted with site made fitting covers in accordance with manufacturers

template.

The suction line from the evaporator to the compressor shall be insulated with a material

having a thermal conductivity of not less than 0.04 W/m ºC and at least 19 mm thick. A

vapour barrier shall protect this insulation, which shall not be broken between joints of

sectional material or at discontinuities at valves or brackets.

External insulation shall be painted with reflective paint.

2.42 LABELS AND IDENTIFICATION

Pipework:

All valves shall be labelled in accordance with a Schedule, which shall correspond to the "as-

fitted" drawings. The labels shall be of traffolyte sandwich, black letters and figures, on white

ground. The labels shall consist of discs attached by chains or wire loops. Each label shall

indicate the type of service (e.g. Heating) and a number, which shall agree with a Schedule.


All plant, motor starters and isolators shall be labelled with labels of sandwich "traffolyte" with

white lettering on black background. The labels are to be screwed to the fronts of starters

and isolators and permanently attached to plant or nearest adjacent wall, etc., and shall

indicate the service, number, item, etc.

Each fan, boiler, pump, etc., shall bear a metal label giving the makers name, date of

manufacture and serial number, test and working pressures, duty, power, phasing, number

of cycles per second, speeds, B.S. number, etc., as appropriate to the item of plant so that it

may be identified at a later date with ease.

At times it is difficult to have permanent labels available for plant handover and at such times

the Contractor shall provide free of charge temporary "tie on" labels so that all valves and

equipment are identifiable.

All uninsulated pipe work, except that visible in offices, habitable rooms, offices, public

spaces, corridors, etc., shall bear identification bands and direction arrows similar to those

used on insulated pipe work, to BS1710:1984.

Ductwork:

This item is based on the Heating and Ventilating Contractors Association Specification

DW/144 Identification of Ductwork.

This Specification applies to the identification with colours and description of ducts for

ventilation, air conditioning and simple exhaust systems.

This Specification provides for the identification of the air conveyed, the direction of flow, the

destination of the air and/or the plant where the air was treated.

2.43 CONTROLS

The H.V.A.C. system installation and controls wiring is to comply with all relevant statutory

authorities and in accordance with the requirements of CIBSE Guide H: Building Control

System.

Generally the operation of the plant shall be automatic but due to the nature of buildings

usage periods an override and extension will be required.

Prior to manufacture and installation of any controls system, schematic wiring and panel

drawings are to be provided for approval of the Contract Administrator.

Controls Panels – General Standards

This section of the Specification covers the manufacture, supply, installation, test and

complete commissioning of the control panels.

The panel main isolator and power distribution system to sub fused circuits shall be suitable

for connection to either a 240V 1-phase 50 Hz supply or a 415V 3-phase 50Hz, 4 wire for

earth neutral supply, with suitable fault rating, dependant on size and loading of the panel.

Sub-fused components within the panel shall be fault rated in accordance with the circuit.

Plant items shall be interlocked for safe and logical operation (e.g.: pumps run before boilers

enabled) delays between loads on start up shall be incorporated where necessary.

Standards – The control panel shall comply with the following standards:

a. 1) Part P of the building regulations:

b. 2) Current IEE Regulations with current amendments.


c. 3) BS 5488 specification for factory built assemblies of Switchgear and Control Gear for voltages up to and including 1000V AC and 1200V DC.

Other standards are referred to for particular items in their relevant sections.

Construction – The panels to be constructed in two sections mains and controls. Cubicle

sizes shall be such as to allow adequate space for access to all components within the

cubicle, for maintenance purposes.

All starters shall have manual/off/auto switches, Run and Fault lamps, control circuit fuse

and power supply fuses. All duplicate items shall be duty/standby via a selector switch with

auto change over on trip unless specified elsewhere.

Note: All lamps and switches on the doors to be of low voltage.

Controls sections shall be fitted with an internal isolator with suitable warning labels on the

section door. Where control circuits are powered from individual cubicles or sections at low

voltage, isolating terminals shall be provided together with suitable warning labels.

Doors shall be a minimum of 2mm thick and shall be folded in the form of a rigid tray,

stiffened internally if required, purpose made to the dimensions of the doors where they are

installed. Doors shall be braced for the fitting of controllers and indicators.

Recessed sealing gaskets shall be fitted to all doors and cover plates to give dust protective

joints at all edges.

Hinges shall be provided to enable the removal of all doors if required. Doors are to be

capable of opening through a radius greater than 90º and a restraining mechanism shall be

provided to prevent any door opening beyond 120º.

All doors shall be provided with locking type door handles using one common key for all

locks on any given project.

All panels shall conform to BSEN 60947:1992, degree of protection IP 54.

Unless otherwise specified, control panels are constructed for front access; allowing all

equipment to be removable from the front of the panel, and all maintenance to be carried out

form the front of the panel. Fixing screws through the outer shell must be kept to a

minimum. Where unavoidable, mushroom or counter sunk head screws shall be used with a

chromium plate finish; except for labels, where plastic rivets the same colour as the label

background may be used.

All live parts accessible to inadvertent contact when a cubicle door is open shall be shrouded

to comply with the Health and Safety at Work Act. Where live equipment cannot be isolated

then it should be covered with a Perspex shield carrying a suitable warning label.

The panel shall have a minimum 1.2M clearance in front for maintenance access.

All components shall be mounted on the equipment mounting/back plates; mounting from the

sides, bottom or top of the panel shell shall not be allowed. Components shall preferably be

DIN rail mounted. Space shall be allowed on the back plates for a minimum of 10% of all

items for future use, and a minimum of 10% spare cubicles, preferably located at low level.

Panel construction shall be such that adequate ventilation shall be provided for the internal

heat dissipation and in no circumstances shall the internal temperature rise above 40ºC.

Should louvred sections and/or mechanical ventilation be required they shall be provided.

A rigid document pocket for wiring diagrams shall be fixed inside the control panel or on the

back of the new panel door.


Panel Finish – A high standard of finish is required for the control panel doors and covers,

the paint is to be applied to a dry rush and grease free metal. The steel may be electro zinc

plated or standard mild steel but either must have a minimum of an etch coat, 2 priming

coats, an undercoat and 2 finishing coats. The undercoat and finishing coats shall be stove

enamelled and the panel shall be rubbed down between coats of paint as required.

A small tin of finishing coat paint shall be supplied for each control panel, colour to be as

advised by the original manufacturer according to his records.

Paint finishes to the new doors/covers shall be full gloss stove enamel to BS 4800 colours.

Final colour to be approved by Contracts Administrator.

The interiors of the panels shall be wiped clean only. The internal backplates shall be

painted gloss white.

Earthing – At one end of the panel the bar shall be fixed to a threaded brass stud which is to

be fixed through the panel with nuts and washers to receive the main earth connection.

The earth bar shall have a low impedance and have a current rating which matches the main

isolator and shall be jointed at panel sections in an approved manner.

Each item of equipment within the control panel shall be separately earthed to its associated

cable.

Earth conductivity by means of door hinges shall not be permitted.

Wiring and Termination – When screened cable is required the screen shall only be earthed

at the controller end, not at the sensor. If the controller is mounted in a panel the screen

must continue through the panel direct to the controller.

Where M.I.C.C. is used the outer metal sheath can be earth at the panel gland. The wiring

inside the panel must be continued in screened cable with the screen earthed at the

controller end only. The junction between the M.I.C.C. cable and the screened cable inside

the panel should be made as close to the M.I.C.C. gland as possible, the screen of the cable

inside the panel must not be earthed at that junction, but should shroud the conductors as

close to the junction as possible.

Control and power wiring shall be kept separate as far as practically possible. All internal

wiring shall be securely fixed to the enclosures and shall not impede the opening and closing

of doors or removal of components. Where possible ‘crimp’ type connections shall be used.

Control wiring shall be run in plastic trunking where possible. The cable shall not occupy

more than 50% of the trunking volume.

Control wiring shall be neatly arranged and cleated. Cleats are to be fixed to the

switchboard structure at sufficient intervals to avoid cable sag. Adequate cable loops must

be allowed to accessories on doors to avoid cable stretch.

Bunching of cables into large looms shall not be accepted. The maximum number of control

cables in any one group shall not exceed 25 conductors. Conductors for heavy loads shall

be routed to ensure adequate cooling and shall be separated from control wiring. All

unfused cables between bus bars, isolators or fuses shall be routed separately as individual

looms.

Extra low voltage cables shall be ribbon cable rated at 300V AC.

Mains cables shall have 600V grade copper conductors, PVC insulated, colour coded as

follows:


Function Alphanumeric Colour

Protective conductors Green and yellow

Functional earthing conductor Cream

a.c. power circuit (1)

Phase of single-phase circuit L Brown

Neutral of single or three-phase circuit N Blue

Phase 1 of three-phase a.c. circuit L1 Brown

Phase 2 of three-phase a.c. circuit L2 Black

Phase 3 of three-phase a.c. circuit L3 Grey

Two-wire unearthed d.c. power circuit

Positive of two-wire circuit L+ Brown

Negative of two-wire circuit L- Grey

Two-wire earthed d.c. power circuit

Positive (of negative earthed) circuit L+ Brown

Negative (of negative earthed) circuit (2)

M Blue

Positive (of positive earthed) circuit (2)

M Blue

Negative (of positive earthed) circuit L- Grey

Three-wired d.c. power circuit

Outer positive of two-wire circuit derived from three-wire circuit

L+ Brown

Outer negative of two-wire circuit derived from three-wire circuit

L- Grey

Positive of three-wire circuit L+ Brown

Mid-wire of three-wire circuit (2) (3)

M Blue

Negative of three-wire circuit L- Grey

Control circuits, ELV and other applications

Phase conductor L Brown, Black, Red, Orange, Yellow, Violet, Grey, White, Pink or Turquoise

Neutral or mid-wire (4)

N or M Blue

(1) Power circuits include lighting circuits.

(2) M identified either the mid-wire of a three-wire d.c. circuit, or the earthed conductor of a two-wire earthed d.c. circuit.

(3) Only the middle wire of three-wire circuits may be earthed.

(4) An earthed PELV conductor is blue.

1mm2 flexible will be the minimum permissible cable size for mains control circuits.

0.5mm2 flexible shall be the minimum permissible cable size for low current control circuits

of 24V only or ribbon cable can be used rated as above.

All internal wiring shall be permanently identified by means of numbered ferrules. These

numbers shall be shown on the schematic wiring diagrams where these are used for point to

point wiring.

Co-axial or twisted pair cable shall be specified on schematic wiring diagrams. Screens shall

be earthed as detailed elsewhere.

Terminals for external control wiring shall be of the isolating type to allow for disconnection of

control circuits for commissioning and maintenance.


Terminals shall be of the cadmium plated stud type of a minimum of M5, for accommodating

claw or clamp type washers with suitable cable lugs. Terminals shall be permanently

labelled with circuit references using cable and core numbering procedures approved by the

engineer, and an insulating barrier shall be provided between connections. A maximum of

two connections only shall be made per terminal.

Main cable terminations shall be of the ‘two stud’ type for accommodating crimped cable

lugs. All terminations shall have clearance holes. Cable lugs, fully threaded bolts, plain and

shake proof washers and nuts shall be provided to sit the cable. Cable tails shall be

supported within the equipment at internals not exceeding 450mm. Supports shall be non-

metallic and be attached by mechanical means.

Isolators – Isolators and switch fuses shall conform to BSEN 60947:1992.

Panels shall be provided with main incoming unfused isolators (except where notified

otherwise) with sufficient auxiliary contacts to enable all live connections entering the panel

to be isolated. Where necessary shrouded isolating relays shall be used together with

isolating link type terminals. Control and interlock circuits shall preferably be powered at the

control panel with local plant isolation via auxiliary contacts of the plant isolators.

All isolators shall be door interlocked on opening sections of cubicles and shall have the

facility for locking in the ‘OFF’ positions, except where internal isolators are specified for

control sections.

For 3-phase 34-wire supplies a neutral link of the same rating as the main conductor shall be

located adjacent to the incoming cable connections. For single phase supplies the neutral

link shall have a rating equal to that of the line conductor. An efficient earth terminal suitably

labelled shall also be located adjacent to the incoming cable terminations.

All isolators shall be rated for fault current make. Main panel and known resistive load

isolators shall be rated for installed full load current break. Starter isolators shall be rated for

motor start current break.

All connection’s that are live, with the isolator, in the open position, shall be fully shrouded by

an insulated cover and identified by a 415V or 240V danger label as appropriate.

Fuses – Power fuses shall be provided for each starter and contactor and these shall comply

with BS 88:2007.

A detailed fuse chart shall be provided and fitted within each panel.

A spare set of fuses containing 10% of the total number of each size of fuse used with a

minimum of 2 for each size, shall be fixed inside the panel with suitable clips adjacent to the

fuse chart.

Starters – Starters for fan and centrifugal pump motors of up to and including 7.5kW shall be

direct on line, above 7.5kW and up to and including 55kW they shall be open transition

automatic star-delta, above 55kW they shall be auto-transformer.

Overloads shall be hand reset, and shall have at least single pole changeover contacts.

Direct on line starters shall comply with BSEN 60947:1992 and shall be rated for intermittent

duty class 0.3.

Automatic star-delta starters shall comply with BSEN 60947:1992 and be rated for

intermittent duty class 0.3. They shall have changeover timers adjustable from one to 30

seconds (subject to fan or pump characteristics). If the overload relays are connected for

phase current, their scales shall be marked to show whether they are indicating phase

current or line current.


Electrical and mechanical interlocks shall prevent both star and delta contacts being closed

at the same time.

All starters and contactors shall have auxiliary contacts suitable for remote monitoring of run

indication. All starters/pair of starters and contactors shall be suitable for remote starting and

stopping of plant via a Building Management System (BMS).

Contactors – All contactors shall comply with BS 5424. Unless otherwise specified

contactors shall be of the same manufacture as the starters and be fully enclosed.

Relays – Relays shall be of the plug in changeover type.

Labels – Labels shall be supplied for all instruments and components mounted on the front

of the control panel. Where a group of indication lights and control switches are associated

with one item of plant, a common label shall be used which should describe the components

of the group.

Within the panel adequate labelling shall be provided for all fuses, relays, starters and

control equipment. Such labelling shall correspond in detail with the panel wiring diagram.

Warning labels shall be provided giving notice of any live low voltage circuits existing when

doors are open or when cover plates are removed. Suitable labels shall be fitted identifying

circuits requiring isolation by link type terminals.

Labels shall be engraved on traffolyte or similar laminate; but as an alternative for internal

labels. Plastic trunking lids may be engraved, in which case the trunking lids must be

identified with respect to location.

Labels shall normally have black lettering on a white background, but safety labels shall be

to BS 5378.

All labels shall be fixed either with mushroom head screws with a chromium plate finish, or

plastic rivets the same colour as the label background. Adhesives shall not be used on

panel fascia other than of maintenance references

Ammeters – All ammeters shall be to BS 89 and shall be provided to replace existing only.

The current passed through an ammeter should to exceed 20 amps inductive or resistive.

Above this rating current transformers must be used. Blade terminals are preferred to

accept insulated plug-on connectors or recessed screwed connections to prevent inadvertent

contact. Ammeters for inductive loads such as motors shall have an extended compressed

scale greater than the value of the starting current.

Ammeters must be selected so that the measured value falls within 20-80% of full scale. No

circuit wiring from the L2 or L3 phases will be permitted on the panel door.

Indicator lamps – Unless otherwise specified indicator lamps shall be of the low voltage LED

cluster type.

RED: Essential equipment stopped by action of a protection device.

YELLOW: Temperature, pressure, humidity etc. Outside normal working limits.

GREEN: Machine started/running in normal condition.

WHITE: Panel live/other non defined uses.

Switches – All switches shall be rotary type and unless otherwise specified shall be break

before make.


In general, switches shall not be capable of continuous rotation; but this may be overridden

for functions such as sequence selection or, in the case of ammeters, phase selection.

Where ‘MANUAL/OFF/AUTO’ switches are provided, the ‘MANUAL’ position shall override

all interlocks except those relating to plant or life safety.

Where interlocks from fireman’s switches or fire relays are provided, these interlocks shall

override the ‘MANUAL’ and ‘AUTO’ positions of ‘MANUAL/OFF/AUTO’ switches.

Instrumentation and Controls – A separate panel section shall be provided for mentation

instrumentation and controls.

All panel fascia items, and adjustable and/or indicating controllers whether fascia or

internally mounted, shall wherever possible, be mounted at a height between 1000mm and

1750mm from finished floor level.

Drawings – Two copies of the panel layout and schematic wiring diagrams shall be

submitted for approval by the Contract Administrator.

The panel layout drawings shall be adequately dimensioned, and shall show the

arrangement of all components mounted on the face of the panel.

The wiring diagrams shall show the electrical ratings and full load currents of all motors and

other equipment supplied from the panel, the ranges of all starter overloads, and all fuse

ratings. All wiring and terminals shall be numbered. References and terminal numbers of all

external equipment connected to the panel shall be shown although it is accepted that this

information may not be available at the time of approval.

When the drawings have been approved, the manufacturer shall issue two copies of all

approval drawings.

When the panel doors/interiors have been built and delivered to site, two copies of the as

manufactured wiring diagrams shall be supplied in a rigid document pocket permanently

fixed behind a non interlocked panel door, e.g.: control section.

Works inspection and testing of all panels shall be carried out testing on site in the presence

of the Contract Administrator.

The paintwork shall be examined for any scratches or blemishes.

The wiring shall be checked for loose connections, and compliance with the wiring diagrams.

The insulation resistance in each case shall not be less than 20 megohms.

1) Phase to phase 2) Phase to neutral

3) Phase to earth 4) Neutral to earth

A test certificate for each panel shall be issued by the manufacturer.

Fireman’s Switch – the override functions are as follows:

Normal/On/Off/Extract only and shall be tested for correct operation.

2.44 DRY RISER

The dry riser installation shall be as indicated on the drawings.

This shall be to the complete satisfaction of the contracts administrator, the Local Fire and

Civil Defence Authority (L.F.C.D.A) and the building control team, who will witness test

consisting as a minimum, water flow through system discharge at top outlet to flush out


debris, then fill with water and test to 10 bar (measured at inlet), held for 15 minutes, with no

leaks allowed.

Inlet and landing valves are to be provided, inlet to consist of a twin inlet breeching piece

with outlets comprising of a landing valve, both complete with glass wired door cabinet to

suit.

A landing valve outlet is to be provided at each floor level including the roof.

The dry riser and associated landing valves are usually located in the main lift lobby area,

and lowest point of the system is usually the breeching inlet point and this shall be complete

with a drain off cock. However, if the inlet is not the lowest point of the system, then a

second drain cock is required at the actual lowest point with label indicating its function.

The entire system shall conform to BS 5306 (part 1) and BS 5041 (part 1 – 5 inclusive).

Dry riser system is to be exponentially bonded.

No elbows are to be used, must be full radius bends only.

Pipe work shall be installed using galvanised mild steel tubing heavy weight quality to BSEN

10255:2004. All joints shall be screwed except at inlet breeching positions and landing valve

positions in which case flanges shall be installed to BS 4504 galvanised and screwed joints.

All pipe fittings shall be constructed from malleable cast iron galvanised to BS1434: 1986

and BS 1256:2000 and having screwed threads complying with BS 21:1985.

Flanges shall be galvanised to BS4504 and complete with sheridised nuts, bolts and

washers. Joint rings are to be full faced and manufactured by 3MM “Klingerite” sheeting or

equal. Nuts, bolts shall be of a type resistant to tampering or unauthorised removal.

Joints are to be made with long hair silken hemp and jointing paste to BS 21:1985.

Inlet breeching and outlet cabinets shall be built in type finished stove enamel red with

Georgian wired glass door and signed in accordance with BS 5041:part5 (1974). Cabinets

to be complete with keyed slam locks.

Breeching pieces are to be twin inlet type sized at 63mm diameter complete with quick

release cap and chain flanged to BS 4504 in accordance with BS 5041:part 3(1975).

Landing valves are to be gate valves, brass with quick release cap and chain, flanged to BS

4504 in accordance with BS 5041:part 2(1975).

Air release valve shall be installed on top of riser and shall be 25mm BSP screwed male end

type.

2.45 DRAINAGE

Above Ground Drainage:

All works shall be in accordance with BSEN 12056:2000 ‘Code of Practice for Sanitary

Plumbing’ the Building Regulations Part H and shall comply with the Local Authority Byelaw

requirements.

All statutory notices legally required for the works shall be given by sub-contractor to the

required statutory bodies.

The sub contractor is to co-ordinate the installation of the above ground drainage.


The work shall be carried out to the complete satisfaction of the Contract Administrator and

the Local Authority.

The soil and waste pipe systems have been designed on the modified single stack system of

drainage whereby some anti-siphon pipe work is required generally as indicated on the

drawings.

Internal main stack pipes to BS EN 877:1999, branch soil pipes, floats and stubs shall be

installed in uPVC to BS 4514 jointed by means of solvent welding and supported with

galvanised standard brackets, where stacks are installed in high riser (over eight stories)

buildings they shall be in cast iron.

Intumescent fire sleeve shall be fitted to all stack pipes where passing through compartment

floors and walls.

Branch waste and anti-siphon pipe work shall be installed in PVC to BS 5255 jointed by

means of solvent

Where standard brackets cannot be used purpose made brackets in galvanised mild steel

shall be used to ensure adequate support for the pipe work and keep alignment correct.

All stacks pipes shall be installed plumb and straight, adequately supported and jointed in

correct manner as recommended by the manufacturer of the pipe work.

All open ends of pipe work left during construction shall be temporarily sealed with plugs to

prevent foreign matter entering the system.

Correct adapters shall be used for jointing different materials together.

Expansion joints shall be installed in the PVC pipe work to facilitate thermal movement in

accordance with the manufacturer’s printed instructions; anchor or fixed points shall be

provided to control thermal movements.

Access doors, pipes and rodding eyes are to be installed in the pipe work to enable the

whole system to be cleaned, rodded and tested.

All fittings, other than WC’s shall be fitted with a white polypropylene deep seal trap to BSEN

274:2002 with union inlet and compression outlet to sizes indicated on the drawings.

The maximum distance between supports shall be as follows:

Vertical Horizontal UPVC pipes 20mm – 40mm 1.2m 0.5m 50mm 1.2m 0.5m 75mm – 100mm 1.8m 0.9m Cast iron pipes 75mm – 100mm 3.0m 1.0m

All pipe work shall be tested in stages and upon completion of the work by means of air

pressure, the system shall be capable of sustaining 75mm WG for 5 minutes or as approved

by the Local Authority.

The Local Authority must be in attendance to approve the final testing.

Fix only new sanitary ware as indicted on the Architects drawings and to detail specified by

the Architect.

Overflows shall be installed in PVC shall comply with relevant Water Regulations.

Below Ground Drainage:


The contractor shall produce working drawings and issue them to the Contracts

Administrator for comment before any installation works take place. Connections to the

existing local authority services shall be agreed and arranged with the local authority.

The contractor shall be responsible for all new connections required to statutory utilities

existing services.

Before work commences, the contractor shall check all invert levels and positions of existing

drains, sewers, inspection chambers and manholes against information shown on the tender

drawings and report any discrepancies to Engineer/Architect.

The contractor shall adequately protect existing live drains and maintain normal flows during

alterations. All existing drains no longer required will either be adequately sealed at both

ends and filled with pulverised fuel ash or completely removed.

The contractor shall flush out the whole of the installation both new and existing to remove

all silt and debris before final testing, before CCTV inspection and immediately before

handover. Safely dispose of washings and any detritus without discharging them into the

sewers or watercourses.

The underground drainage installation shall be in accordance with the requirements of

BS8031 “Building Drainage”, and the requirements of the Local Authority.

Under slab drainage shall be installed in plain ended vitrified clay pipes and fittings to BS EN

295 Part 1 jointed with polypropylene push fit couplings as manufactured by Hepworth

Building Products.

The sides of pits and trenches shall be adequately supported at all times but must be

removed sufficiently to permit compacted filling of all spaces.

Trenches shall be excavated to the required depth and line and should be as narrow as

possible but not less than the pipe diameter plus 300 mm. The sides of the trenches must

be vertical from the bottom up to 300mm above the crown of the pipe. All hard lumps,

boulders and projections on the trench bottom shall be removed; soft spots shall be

hardened by tamping in bedding material.

All trenches shall be kept free from water whilst installing pipelines; trench bottoms shall also

be protected against disturbance by foot traffic.

Trenches in areas of fill or in disturbed ground shall be made up with ballast rejects and/or

small hardcore less than 75mm and topped with 50mm concrete blinding to form trench

bottoms.

External drains with a cover depth of 600mm or more shall be laid a minimum of 100mm

thick granular bed with the remaining trench filled to a level at least 100mm above the pipe

crown.

External drains less than 600mm cover and those below the building slab shall be encased

in a minimum of 150mm of concrete, flexibility being maintained by means of the insertion of

a 25mm thick polystyrene board at each joint pre-cut to the pipe diameter and equal to the

cross sectional area of concrete.

The trench bottom shall be filled with a layer of granular material to BS 822 (10mm single

sized) and be thoroughly compacted to a depth of 100mm across the whole width of the

trench, hand holes being scooped out at each joint to enable pipes to rest informally on their

barrels. After testing, lay and compact further granular material in 100mm layers to 100mm

above the crown of the pipe. Ensure that the pipes are not displaced or floated as

compaction takes place.


Backfilling the trenches shall be with selected back fill from site or imported and shall be

readily compacted spoil, free from large than 40mm stones, building rubbish, roots vegetable

matter, frozen soil and lumps large than 75mm and shall be laid and compacted in layers of

150mm minimum over the whole trench area to a depth of at least 300mm over the crown of

the pipe, backfill above this level shall be laid and compacted in layers not exceeding

300mm loose depth.

There must be at least 600mm of compacted backfill before any mechanical compaction

takes place.

All “Y” branches on the main drain run shall be at 135 degrees.

Bends, gullies and other terminal fittings shall be bedded and set in concrete.

Where branch drains run at steep slopes and connect into main runs, adequate concrete

thrust blocks shall be provided to prevent undue stresses on the main drain and forcing it out

of alignment.

All open ends of pipes and manholes shall be temporary sealed to prevent ingress of debris.

All cement used in connection with drainage works shall be sulphate resisting.

Bends at the foot of the stack pipes shall long radius with duct foot set plumb on concrete

bed and haunch.

Flexible joints shall be installed to all inlets and outlets of manholes as close as practicable

to the external face of the manhole wall but not more than 150mm away.

Where drains exit the building 2 No. Flexible joints shall be installed to form a rocker pipe

and be located as close as practicable to the building wall, concrete lintels or pipe sleeves

shall also be provided and installed with a clear 50mm void around the drain filled with foam

to prevent ingress of concrete and debris.

All drains shall be laid in straight lines and to one gradient between manholes of access

points.

Correct adapters shall be used when connecting new drainage to existing or to different

materials.

Yard gullies shall be Hepworth RGP5 225mm diameter x 585mm deep complete with RGP6

grating and IBP3 basket.

Gullies for drainage of RWPs shall be Hepworth figure SG1/2 trap and SH3/2 square top

hopper with back inlet where required and fitted with grating and frame.

Manholes 1.2m or less shall be constructed in 225mm thick semi engineering brickwork

jointed in English bond flush pointed, ensure all joints are solidly filled with mortar. Bricks

are to be solid type similar to ‘south waters’ and frogs laid upwards.

Manholes over 1.2 metre deep shall be constructed in pre-cast concrete sections to BS 5911

surrounded with 150mm graded concrete and tied into the structural concrete foundation raft

by means of reinforcing rods, ensuring all joints are well buttered up in 1:1 cement/sand

mortar and finished smooth and flush on completion.

Shallow manholes were indicated on the drawings and less than 900mm deep can be one

piece polypropylene and surround in 1500mm of concrete, tied into the raft with reinforcing

rods.

The mortar mix shall be 1.3 cement/sand Sulphate resisting.


All manholes shall be built up form 200mm thick concrete bases.

Open channels in the bottom of manholes shall be formed with half round channels, tapers

or beds as may be required. Branch channel bends shall be standard half section with

uniform 250mm projections.

Step irons in galvanised malleable iron to BS 1246 shall be built into the manhole walls

where the depth from the surface to the invert exceeds 900mm. The first step iron shall be

450mm form finished level at 300mm centres on plan and 300mm vertically in a staggered

fashion.

Backdrops, vertical drops shall be installed in vitrified clay pipe work and fittings external to

the manhole and surrounded in 150mm minimum of concrete. The manhole base slab shall

be oversized when poured with an overhand to accommodate the load of the backdrop.

Internal cast iron drain backdrops can be used where space allows, and shall have a square

door access bend on top.

Benching in manholes shall rise vertically from the top edge of the channel to a height, not

less than that of the soffit of the outgo, and be sloped upwards at 1:12 to the edge of the

manhole wall. Rough concrete benching using 10-14mm aggregate shall be gloated over to

a smooth hard finish with a cost of 1:2 cement/sand mortar laid monolithic with the benching.

The top of the vertical section of the benching shall be rounded off to a 25mm radius.

Branch drain benching shall be shaped around the channel branches as to guide the flow of

effluent in the direction of flow.

Gullies in paved areas are to be trade Nickel Bronze finished as detailed on drawings.

Branch connections at manholes are to be formed using half round slipper bends in direction

of flow.

Alterations of existing manholes shall be reconstructed as described for new manholes.

Manhole covers and frames positioned externally and in the car port shall generally be cast

iron in accordance with BSEN 124:1994 medium duty generally and heavy duty where

subject to lorry and heavy good vehicles.

All covers are to be fully accessible and visible.

Manholes covers and frames shall be set square and level, well bedded and haunched in

concrete and are to be drainage system types as noted on drawings.

All covers shall be set in grease after final testing and completion of the works.

Where manhole covers are located in the paved landscape or as in accordance with the

Architects requirements the manhole covers shall be a brick pave recessed manhole cover

with galvanised steel frame and shall be typical of the following:

Heavy duty manholes covers manufactured by Drainage Systems type no. 6333 in locations

where vehicular access is required.

Medium duty manhole covers manufactured by Drainage Systems type no. 6332 in locations

restricted to Pedestrian Access.

The above manhole covers to be suitable to receive the landscape paving blocks specified

by Architect.

The Contractor is to provide clean water, assistance and apparatus for testing and

inspections as required.


Testing, all drain runs shall be tested before backfilling is commenced, and again upon

completion of backfilling and reinstatement to ensure the soundness of the system, any

defects are to be corrected at the Contractor’s expense.

All testing shall be in accordance with the code of practice for drainage BS 8301 and as

required by the Local Authority.

Due notice shall be given to the Local Authority and the Contract Administrator to be present

when a particular line is being tested, and only when approved shall backfill be commenced.

On final tests a certificate shall be presented by the Contractor for signature by the Local

Authority and/or Contract Administrator.

The Contractor is to allow for a CCTV video survey of the complete system to be carried out,

drainage, this is to be undertaken when all tests and reinstatement works have been

completed, a copy of the video and report shall be issued to Contract Administrator before

handover.

Existing drainage runs not required for the new works shall be grubbed up, in filled with

concrete or sealed by means of a drain plug and concrete packing. Unwanted slipper bends

in manholes shall be removed the drain plugged and benched over to the lines of the

existing benching.

Redundant manholes shall be cut down at least 300mm below finished levels, filled with

hard-core and topped over with 150mm thick concrete.

The Contractor is to provide his own drawings locating all underground drainage points,

manhole positions and gullies etc. and shall liaise with the mechanical sub-contractor to

ensure that drainage points are correctly positioned to suit the above ground drainage.

At completion of the underground drainage works record drawings shall be prepared by the

Contractor, a copy of which shall be issued to the supervisory officer for comment, two

weeks before handover.

2.46 CHLORINATION AND WATER SAMPLING

After all work has been completed on the hot and cold systems, these shall be

sterilised/chlorinated in accordance with BS 6700:2006 Section 13.9 generally, as follows:

Before chlorination, service pipes, tanks and cisterns shall be flushed out to remove dirty

water, debris etc., refilled with clean water and flushed again.

No water shall be used for domestic purposes during this flushing operation, nor until

chlorination has been completed.

The whole of the water services apparatus is to be filled with a solution of 50 p.p.m. (50 mg

per litre) chlorine in water. The solution shall be distributed throughout the system and

remain in the system for 24 hours and longer if conditions demand and at the end of this

period the chlorine residual in all parts of the system should be at least 30 p.p.m. Tests of

the strength of the solution shall be carried out periodically and in the presence of the

Contract Administrator.

Warning notices must be placed at all entrances to the building whilst chlorine is in the

system.

Chlorine concentrated solution is to be mixed with the water in the break tank (if any) and the

cold water storage cistern, then the pump (if any) operated and all taps opened and flushing

cisterns operated until the resultant diluted solution is drawn through the whole of the pipe

work system at a concentration of 50 p.p.m.


When satisfactory, sterilisation has been effected the system is to be thoroughly drained,

refilled and drained again before finally filling for use, ensuring that the free chlorine

concentration is no greater than 0.5 p.p.m. Or that present in the water supply mains,

whichever is the greater. Mains cold-water services shall be carried out in a similar manner

except chlorine solution shall be injected into the mains distribution pipe work.

At the end of the Contract, but prior to handover, the Contractor shall take samples of water

from the following points in the system:

a. Rising main to cold water tanks;

b. From the boiler drain cocks or other lower points in the system.

These samples shall be analysed and the Contractor shall report to the Contract

Administrator.

At the same time the Contractor shall report to the Contract Administrator any discolouration

of the water in the systems.

2.47 BOILER DOSING EQUIPMENT

The following equipment shall be installed:

a. 15 litre dosing pot in the boiler house manufactured by Aldous and Stamp Ltd, suitable for the system pressure.

b. Filling funnel connected to dosing pot with cover, lockshield valve and drain valve.

The pot shall be connected to the system pipe work with lockshield valves.

A line constructed from light gauge copper tube shall be run from the drain valve to the

nearest gully.

2.48 FLUSHING OUT

Prior to commissioning the system, and in the presence of the Contract Administrator, the

whole of the pipe work shall be flushed out by the Contractor by connecting a high pressure

pump to the pipe work and running the waste water to drain.

The Contractor shall ensure that all pipe work is free of scale and other sediments and the

process shall continue until the Contract Administrator is satisfied that the pipes are free

from all foreign matter.

It is the responsibility of the Contractor to allow adequate connection points on the pipe work

for the pump connection and to supply suitable pumps and hoses. A Practical Completion

Certificate will not be issued unless the above process has first been completed.

This process shall be in accordance with Application Guide 1/89 "Flushing and cleaning of

water systems" (June 1989) as published by B.S.R.I.A.

2.49 COMMISSIONING

The commissioning of the building services systems shall be overseen by commissioning

agent, see particular specification, and the following clauses. The commissioning should be

carried out to the CIBSE code M “Commissioning Management (2003)” and BSRIA Guides

A/G 5/2002 “Commissioning Management” and A/G 16/2002 “Variable Flow Water Systems,

Design, Installation and Commissioning Guidance”.

2.50 COMBUSTION EFFICIENCY TESTS


A combustion efficiency test shall be carried out on the completed boiler installation in

accordance with CIBSE Code B-Boilers (2002). The Contractor may carry out the tests

providing he has the necessary experienced staff and instruments available. Alternatively,

the Contractor shall arrange for the tests to be carried out by a competent independent

authority.

All necessary access shall be allowed for by the contractor.

The Contract Administrator or his representative shall be given due notice when testing is to

be carried out and shall be present at each test.

The tests shall demonstrate to the Contract Administrator that the combustion efficiency of

each boiler is not less than that guaranteed by the Contractor in his tender. The combustion

efficiency shall be based on flue gas temperatures taken at the flue gas exit from each boiler.

A period shall be allowed to permit steady state conditions to be reached before testing

takes place, and to assist in maintaining a steady rate of firing, the automatic control

arrangements may be rendered inoperative for the period of the test.

It is the responsibility of the Contractor to provide copies in duplicate of the test figures

obtained, and costs incurred shall be included in his Tender Sum.

The boiler(s) shall be commissioned strictly in accordance with 'Commissioning code B:

Boiler plant' published by the Chartered Institution of Building Services Engineers.

2.51 SYSTEM PERFORMANCE TESTS – HEATING SYSTEMS

The Contractor shall allow in his tender for carrying out heating system performance tests.

The tests may be witnessed by the Contract Administrator or his representative but in any

event the Contractor shall provide the Contract Administrator with records of the

performance tests prior to the plant being handed over to the Employer. Prior to the tests

the system shall be hydraulically balanced and all controls shall be operational.

Balancing shall be carried out strictly in accordance with "Commissioning Code W: Water

Distribution Systems" published by the Chartered Institution of Building Services Engineers

and the commissioning water systems application principles AG 2/89.3:2002, AG 2/89.2

Commissioning of water systems in buildings, and AG 20/95 Commissioning of pipe work

systems – design considerations AG 16/2002 Variable flow water systems design,

installations and commissioning guidance, AG 1/2001 Pre-commissioning cleaning of

pipework systems published by the Building Services Research and Information Association

(BSRIA).

a. Demonstration that the installation is capable of providing the internal design temperatures. Tests will not be deferred until the outside temperature is coincident with the design outside temperature.

b. Demonstration that all controls, time switches are operational and that all safety devices work. Thermograph readings will be required as evidence that control systems are operational.

c. Check of all thermometers.

d. Check of all motors, pumps, etc.

e. Check of all pumps.

f. Check of pressurisation fill unit, expansion vessels and pressure controls.

Test No. (a) shall be recorded in the following manner:

a. Outside temperature: - Initial, final and weather.

b. Boiler flow and return temperatures, zone and where needed flow and return temperatures to risers or sub-zones.


c. Individual room temperatures.

d. Individual radiator flow and return temperatures.

The Contractor shall provide in his tender:

a. For all tests points so that the tests may be made.

b. For the attendance of specialists to assist in the tests and for all plant and instruments required to carry out the tests.

2.52 SYSTEM PERFORMANCE TESTS – HOT AND COLD WATER SERVICES

The Contractor shall allow in his tender for carrying out hot and cold water system

performance tests. The tests may be witnessed by the Contract Administrator or his

representative but in any event the Contractor shall provide the Contract Administrator with a

record of the tests prior to the plant being handed over to the Employer. Prior to the tests

being carried out the systems shall be hydraulically balanced and controls shall be

operational.

The hot and cold water services shall be commissioned directly in accordance with

'Commissioning code W: Water Distribution Systems' published by the Chartered Institution

of Building Services Engineers and the Application Guide 2/89 AG 2/89.3:2002

"Commissioning water systems application principles” AG 2/89.2 Commissioning of water

systems in buildings, A/G 1/2001 Pre-commissioning cleaning of pipework systems and AG

16/2002 Variable flow water systems design, installation and commissioning as published by

BSRIA.

Notwithstanding the provision of the above code, the following tests shall be performed:

a. Outflow tests which shall be carried out and recorded as recommended in B.S. 6700:2006 or BS CP 342:Part 2:1974, as appropriate.

b. Record of pressure at appropriate points throughout the systems. Initial and final pressures should be given.

c. Demonstration that the heating surface in cylinder or calorifiers is as specified. Record initial and final temperatures and times.

d. Demonstrate that all controls, thermostatic valves and hand operated valves are operational.

e. Record surface temperatures over lagging on cylinders for the recorded storage temperature.

f. Confirm that there is no evidence of noise or water hammer under the various test conditions.

The Contractor shall provide in his Tender:

g. For all test points so that the tests can be made.

h. For the attendance of specialists to assist in the tests and for all plant and instruments required to carry out the tests.

2.53 SYSTEM PERFORMANCE TESTS – GAS SYSTEMS

The Contract Administrator requires the Contractor to test the entire gas piping system.

These tests may be witnessed by the Contract Administrator or his representative but in any

event the Contractor shall provide Test Certificates as proof that the tests have taken place.

Where piping and fittings are to be buried, test shall be made before the piping is buried, i.e.

the installation shall be tested in sections if the programme of work so indicates.

A final test shall be made on completion. The test(s) is to be made with air under pressure

to 900 mm water gauge or twice the working pressure whichever is the greater. The

pressure shall be held for 20 minutes and the test shall be satisfactory if there is no fall in


pressure during that time. If the test shall be unsatisfactory the work shall be made good

and the test re-applied. The cost of the test(s) and the necessary plant and instruments shall

be the Contractor's responsibility.

When appliances have been connected to the supply the Contractor shall demonstrate to the

Contract Administrator or his representative that the system and appliances are satisfactory.

The Contractor shall allow in his tender for the attendances of British Gas and any appliance

manufacturers as necessary to assist in the test and demonstration of the system.

2.54 SYSTEM PERFORMANCE TESTS – VENTILATION SYSTEMS

The Contractor shall allow in his tender for the carrying out of ventilation system

performance tests. The tests may be witnessed by the Contract Administrator or his

representative but in any event the Contractor shall provide the Contract Administrator with

records of the performance tests prior to the plant being handed over to the Employer.

The ventilation system shall be commissioned strictly in accordance with "Commissioning

code A: Air distribution systems”, published by the Chartered Institution of Building Services

Engineers and Commissioning air systems application procedure for buildings AG

3/89.3:2001 and AG 1/91 Commissioning of VAV systems in buildings as published by the

BSRIA.

The Contractor shall provide in his tender:

a. For all test points so that the tests may be made, these are to be sealed for reuse after initial use.

b. For the attendance of specialists to assist in the tests and for all plant and instruments required to carry out the tests.

Notwithstanding the requirements of the above commissioning code, the following

information shall be passed to the Contract Administrator prior to acceptance of the plant:

a. Velocity of air entering or leaving ventilation terminal unit.

b. Volume of air entering or leaving ventilation terminal unit.

c. Velocity of air in main and branch duct.

d. Volume of air in main and branch ducts.

e. Static and velocity pressures in main and branch ducts.

f. Velocity of air entering and leaving fans.

g. Volume of air entering and leaving fans.

h. Pressure drop across fan.

2.55 SYSTEM PERFORMANCE TESTS – CONTROL SYSTEMS

The Contractor shall allow in his tender for carrying out control systems performance tests by

the controls specialist.

The tests may be witnessed by the Contract Administrator or his representative but in any

event the Contractor shall provide the Contract Administrator with a record of the test prior to

the plant being handed over to the Employer.

The control system shall be commissioned strictly in accordance with 'Commissioning code

C:’ published by the Chartered Institution of Building Services Engineers.

2.56 SYSTEM PERFORMANCE TESTS – REFRIGERATION SYSTEMS


The Contractor shall allow in his tender for the carrying out of performance tests on the

refrigeration system installed (VRV, Split or Multi-split, etc.).

The tests may be witnessed by the Contract Administrator or his representative, but in any

event the Contractor shall provide the Contract Administrator with records of the

performance tests prior to the plant being handed over to the Employer.

The refrigeration systems shall be commissioned by the Specialist Contractor and in

accordance with "Commissioning Code R: Refrigerating systems" TM 1/88.1 and TM 44

inspection of air conditioning systems as published by the C.l.B.S.E.

Notwithstanding the provision of the above codes the following tests shall be carried out.

a. Demonstration that the installation(s) is capable of providing the internal design temperatures either heating or cooling mode as necessary to meet the room heating or cooling load requirements.

Tests will not be deferred until the outside temperatures or room load conditions are coincident with the design parameters. In this respect forced heating or cooling loads are to be made available by the Contractor (i.e. temporary heaters/coolers) for these testing purposes.

b. Demonstrations that all controls, time switches and safety devices are operational.

c. Thermograph readings will be required as evidence that the system(s) are functioning correctly. Such testing instruments shall be provided for by the Contractor and allowed for in his tender.

d. All remote room units, fan coil units, ceiling cassettes, etc., are to be tested as an integral part of the refrigeration system.

e. All refrigerant gas operating pressures (suction/liquid) temperatures, etc., at each piece of equipment is to be checked and recorded in accordance with the relevant C.l.B.S.E. Code.

2.57 THERMAL MODELLING

In accordance with the requirements of the latest Building regulation L and all it’s relevant

sub parts, the contractor shall allow within the Tender costs to provide a thermal modelling

report on the project, that will give all information on the project regarding the thermal

performance, target and final CO2 emissions and confirmation of compliance with the

Building regulations against a notional building.

2.58 GENERAL DUCTWORK

The ductwork services installation shall follow the details set out in the accompanying

documentation, the Chartered Institute of Building services engineers and shall be installed

in accordance with the recommended publications by the heating and ventilating contractors

association entitled:

DW/143 A practical guide to ductwork leakage testing

DW/144 specification for sheet metal ductwork

DW\154 Specification for plastic ductwork

DW/172 standard for kitchen ventilation systems

DW/191 Guide to good practice glass fibre ductwork

TR19 Internal cleanliness of ventilation systems.

2.59 DISTRIBUTION DUCTWORK


Ductwork, Fittings and Supports:

Low Velocity:

This section is based on the Heating and Ventilating Contractors Association Specification

DW/144 for rectangular and circular and oval ductwork.

This Specification applied to systems having average velocities not in excess of 10 m/s, and

positive and negative static pressure not greater than 5 millibars for plant connections.

Unless indicated to the contrary on the Tender Drawings, bends, branches, tees,

expansions, contractions and changes of shape shall be in accordance with the Standard

Specification. Where the Standard Specification is in conflict with the drawings, the drawings

take precedent.

2.60 DUCTWORK

The Contractor shall supply, deliver and install the complete range of ductwork, as indicated

on the drawings and in accordance with this Specification.

The Contractor shall check the building dimensions and the dimensions of plant on Site

before the fabrication of ductwork is started. Working drawings shall be submitted to the

Contract Administrator prior to manufacture.

The ductwork shall be constructed from best quality galvanised mild steel sheets, braced

and stiffened, in accordance with DW/144, published by the Heating and Ventilating

Contractors Association.

Square or mitred bends shall only be installed in the positions shown on the Drawings.

Transformation or taper pieces shall be fabricated so that the angle on any side does not

exceed 22.5%. Ductwork and supports shall be fabricated without sharp corners and edges.

All flanged joints shall be provided with a full faced rubber gasket and, where slip joints

occur, they shall be sealed by non-hardening sealing compound and adhesive tape.

The Contractor shall ensure that all bends have a throat radius of a least half the width of the

duct and bends fitted with air turns shall be used where indicated on the drawings and shall

be of the double skin aerofoil pattern.

All supports and brackets shall be painted with one coat of red oxide to and after erection.

All nuts and bolts shall be sheradised.

Where ductwork passes through the building fabric, galvanised steel sleeves shall be

provided. A glass fibre packing shall be inserted between the ductwork and sleeve to

prevent transmission of air and noise from one space to another and the effects of vibration

on the structure.

The Contractor shall make provision for cleaning the ductwork system with an efficient

vacuum cleaning plant immediately prior to initial operation of the system.

Plastic Ductwork:

Plastic ductwork and fittings are to be of high impact, rigid, un-plasticised P.V.C. having a

tensile strength of not less than 5 lb bars per 25 mm notch (charpy) at 20 deg. C.

They should be of light grey colour with factory welded joints and provided with socket and

spigot joints for site erection.

All site joints must be airtight and made with a suitable solvent cement conforming with a

specification to be approved by the manufacturers of the plastic ductwork.


Sheet Metal Ductwork:

The thickness of ductwork and the stiffening to be used must be in accordance with the

recommendations contained in the D.W. 144.

External ductwork, including that exposed on roof, to be at least 16 gauge, galvanised after

manufacture, and must conform with the current Building Regulations. All ductwork used in

bathroom or toilet extract systems shall be constructed from a minimum of 16 gauge sheet

steel, galvanised after manufacture.

All joints on rectangular ducts with the longest side equal to or greater than 600 mm shall be

flanged.

All angle, channel and flat mild steel duct supports, etc., are to be galvanised (welded work

to be galvanised after manufacture), zinc sprayed or otherwise rust-proofed although not

specifically mentioned under each clause.

All constructional joints, seams, etc., are to be close riveted with rivet spacing at not more

than 75 mm centres, made in an approved manner. Welded joints must not be used except

in special circumstances, and then only with the approval of the Contract Administrator.

Where ductwork is visible no seams will be allowed on the side or sides exposed to view.

All bends are to have a minimum radius to centre line of duct, equal to the width of duct

except where otherwise indicated.

All connections to plant and masonry shafts, etc., are to be made with angle iron flanges with

insertion pieces to minimise the transmission of vibration and to form airtight joints.

Test holes are to be provided in ductwork in suitable positions sealed after initial use for

future reuse.

No permanent erection of the work shall be carried out until the builders work ducts, false

ceilings, partitions, walls, timber and other builders work in connection with the ventilation

services have been approved by the Contract Administrator.

All joints shall be secured with rivets and sealed in an approved manner. The ductwork shall

be constructed from M5 sheet galvanised after manufacture and all cut edges shall be wire

brushed and painted with two coats of "Galvatite".

All external uninsulated ductwork shall be painted with two coats of bitumastic paint on

completion. Where there is any corrosion the metal shall be wire brushed prior to painting.

All brackets shall be wire brushed and painted with two coats of (non lead based) paint after

installation. Where ductwork passes through roof the Contractor shall supply and install a

suitable weatherproof collar to allow the roof to be sealed.

2.61 CLEANING/ACCESS DOORS

Access openings shall be provided in ducting systems adjacent to the following items of

equipment. Fire dampers, smoke dampers, automatic temperature and humidity detecting

equipment, on each side of “inline” fans, filters, heater batteries and other items of

equipment also access doors for “duct cleaning” at commissioning and future. All kitchen

extract ductwork cleaning doors located to facilitate complete cleaning of the entire duct run,

as required by DW/172.

Where possible openings shall be 375 mm wide by 300 mm high with cover plates

constructed from galvanised mild steel. The opening in the duct shall be adequately re-


inforced, with the cover being made air tight by means of a rubber gasket, held by a

minimum four threaded bolts and wing nuts.

All ductwork shall be thoroughly cleaned prior to final commissioning air/balancing and be

sterilised.

2.62 DAMPERS (AIR HANDLING PLANT)

Dampers to facilitate control and regulation of the air flow shall be provided in the positions

indicated in the Tender Drawings. Control dampers shall be selected to match the

characteristics of the system to which they are to be installed and sized in accordance with

the manufacturers recommendations.

Where the selected damper is smaller than the cross sectional area of the plant or duct in

which it is be installed, the Contractor shall install a blank off plate in the plant to prevent air

by-passing the damper installation. Dampers shall be constructed to prevent no more than 5

percent air volume leakage when in a closed position and subjected to a static pressure of

1500 kn/m squared (6 ins H20).

Blades may be of hollow section galvanised sheet steel, 18 gauge minimum, or may be

formed from two sheets or galvanised sheet steel, 22 gauge minimum, spot welded together

to form a rigid blade section. Blades shall be mounted on square section steel spindles,

shouldered and turned at the ends to fit into suitable bearings. Blades may be fitted with felt

or butyl rubber edging strips in order to achieve the specified leakage rate.

Damper frames shall be formed to provide flanged duct, plant or builders work connections

and suitably drilled for matching flanges. Flanges may be of standard mil steel angle section

galvanised after manufacture, or be an integral part of the damper frame and formed from

galvanised sheet steel.

Frames shall be constructed from 13 gauge minimum, galvanised sheet steel and formed

into a "hat shaped" channel section, the completed frame being made rigid by corner braces.

Bearings may be of either bronze or nylon with oil impregnated sintered metal bushes or

alternatively may be of the ball race type.

Individual blades shall not exceed 225 mm in width of 1500 mm in length and larger dampers

shall be multi-leaf equipped with linked operating gear. Inter-connection blade linkages shall

be external to the conditioned air stream.

Automatic dampers shall be provided with a suitable galvanised steel pedestal for mounting

the operating motor or thruster out of the air stream. Manually set dampers shall be

provided with operating arm, position indicating plate and locking mechanism.

Approval of the proposed dampers shall be received from the Contract Administrator prior to

the installation being commenced.

2.63 DUCT MOUNTED DAMPERS

Dampers to control and regulate the air flow in supply and return air ducts shall be provided

in the positions indicated on the Tender Drawings.

Damper blades in rectangular ducts shall not exceed 225 mm in width and 1500 mm in

length and larger dampers shall be multi-leaf equipped with linked operating gear to provide

opposed blade movement. Blades shall be of hollow section constructed from galvanised

sheet steel of not less than 18 gauge, mounted on square section steel spindles, shouldered


and turned at the ends to fit into suitable bronze, nylon or ball race bearings. Blade tips may

be felt tipped to prevent air leakage when in closed position.

Damper frames shall be formed from galvanised mild steel sheet or not less than 13 gauge

formed into a channel section to make a rigid rectangular assembly. Flanges shall be drilled

for matching flange connection, and shall project sufficiently to give protection to the blade

linkages, which shall always be located out of the air stream and readily accessible.

Manually set dampers shall be provided with an operating arm and locking and indicating

quadrant, and marked after balancing.

Where the operating arm is located at high level relative to the floor, dampers shall be

provided with remote operating gear of the sheathed flexible cable type. The operating

mechanism shall be such that no undue strain is placed in the cable and that movement may

be achieved without excess effort.

An externally mounted dustproof cover shall enclose the gearing and be complete with

coloured visual blade position indicator and locking wheel.

The damper casing shall be of double skin construction manufactured from roll formed

galvanised 16 gauge steel outer frame and 20 gauge steel inner frame. The outer frame

shall have continuously welded corners and integral peripheral flanges pre-punched with

elongated holes for ease of duct attachment and infinite height adjustment

2.64 TERMINAL DAMPERS

Grilles and air diffusers with rectangular neck connections shall be provided with an opposed

blade damper, screwed or riveted to the neck connection and designed specifically to

facilitate the final balancing of the system.

Damper frames, blades and operating mechanism shall be constructed from an aluminium

alloy or alternatively from mild steel suitably finished to give full protection to the material

during its designed working life.

Blades shall be made of solid section material and shall be firmly held in position by a spring

steel retaining mechanism. The blade setting mechanism shall be accessible through the

grille or diffuser blades and shall be suitable for operation with an Allen Key.

Where dampers are visible through grille or diffuser they shall be finished with a matt black

paint.

2.65 FIRE/SMOKE DAMPERS

Fire or smoke dampers shall be provided in positions indicated on the Tender Drawings.

Fire dampers shall be constructed to meet the test requirement laid down in B.S. 476, with a

one hour fire resistance. For in duct air velocities of up to 7.75 m/s the following types of

damper may be used. Dampers are to be out of air stream type complete with adjacent

access panel

Single blade vertical sliding, single or multi-blade hinged, single blade offset hinged or the

vertical shutter type. In vertical shafts multi-blade types shall not be fitted.

Each fire/smoke damper assembly shall be held in the open position by a fusible link or

thermal cartridge, designed to release the damper blade(s) at a temperature of 72°C,

complying with BS5588 Part 9:1999.

Each fire damper shall have at least the same standard of fire resistance as the wall or floor,

which the duct passes; unless otherwise indicated it shall have a fire resistance rating of one

hour (B.S. 476:24: 1987). When a fire resistance rating of four hours is required either two


dampers - on each side of the wall or floor - or a single damper having a fire resistance

rating of four hours certified by the Fire Research Station shall be provided.

In a horizontal duct the fire damper may be of either the single bladed or the multi bladed

pivoted type, in a vertical duct the closing force shall be provided by a stainless steel spring.

A multi-bladed damper longer than 1000 mm shall be controlled by two linkage tie roads.

Each fire damper shall be of 1.6 mm thick sheet or steel/asbestolux/steel sandwich of

equivalent fire resistance.

It shall be galvanised or otherwise treated after fabrication to prevent rust. It shall be set in a

casing of galvanised sheet steel of at least 1.6 mm thick provided with stiffeners as

necessary to support the bearing plates. The clearance between the edges of the damper

and the casing shall be at least 0.25 mm for each 25 mm of damper or width. Where the

damper will be fitted to a wall or floor the casing shall be provided either with lugs for building

in or with a frame of angle iron not less than 35 mm x 35 mm x 6 mm at each end. Each fire

damper blade shall be fixed off centre to a substantial steel spindle which shall rotate freely

in bearings supported on the outside of the casing. The damper shall close against a 25 mm

x 25 mm x 3 mm angle iron stop fixed to all four sides of a rectangular casing or to the full

circumference of a circular casing.

Multi-leaf damper blades shall overlap by at least 20 mm.

Prior to the installation of any fire damper the Contractor shall receive approval from the

Contract Administrator or his representative, and the local Authority if required to do so.

2.66 ATTENUATORS

The Contractor shall supply, deliver, install, test and commission all attenuators shown on

the Drawings and given in the Schedules.

All attenuators shall be as selected from the list of preferred manufacturers. Each attenuator

shall be selected to ensure a pressure drop of not more than 50 N/m squared.

Rectangular Attenuators:

Attenuators shall be purpose built units constructed by a specialised supplier to meet the

performance design criteria laid down in the current C.I.B.S.E. Guide or HVCA standard for

kitchen ventilation systems DW/172.

The attenuator casing shall be constructed from galvanised mild steel sheet with longitudinal

lock formed joints. End flanges shall be fabricated from mild steel angles and galvanised

after manufacture. Casings and flanges shall be to the following minimum gauges and sizes:

Attenuator Longest Casing Angle Iron Flanges

Gauge

Up to 450 mm 20 25mm x 25mm x 3mm

450 mm - 915 mm 18 38mm x 38mm x 5mm

915 mm - 1220 mm 18 50mm x 50mm x 5mm

1220 mm and above 16 50mm x 50mm x 5mm

Acoustic splitters shall be rigidly held in place within the attenuator casing and shall be an

incombustible and inorganic material of low or non-hygroscopic nature. Exposed surfaces

shall be bonded or covered to prevent erosion of the surface particles by the air stream, and

must be suitable for insertion into air streams with a velocity of up to 25 m/s.


2.67 GRILLES AND DIFFUSERS

The Contractor shall supply and install grilles and diffusers as indicated on the Drawings or

in the Schedules and in accordance with this Specification.

A foam plastic gasket shall be provided behind each grille and diffuser to prevent streaking

of walls or ceilings.

All grilles and diffusers shall be in accordance with those given in the Schedules or shown on

the drawings and finished to a colour to be agreed with the Contract Administrator.

2.68 WEATHER LOUVRES

The external weather louvres shall be provided and fixed by the Main Building Contractor

and forming part of the external (fabric) appearance of the building.

Louvres shall be constructed of aluminium extrusions and be completely weather-proof. The

Contractor shall make due allowance for connecting to these louvres with a permanent fixing

and provide a bird mesh screen which shall be fitted at the back of the louvre and finished in

a synthapulvine or other approved type factory applied finish.

The louvres shall be in accordance with those shown on the drawings.

2.69 AIR HANDLING UNITS AND FAN COIL UNITS

Where air handling units are indicated on the drawings or called for elsewhere in this

Specification, these shall be constructed in accordance with the appropriate ductwork

specification and as detailed in the particular specification. All as described in the particular

specification.

2.70 FANS

It is the Contractor's responsibility when ordering, to ensure that the equipment ordered is

suitable for the application to which it is to be put.

All fans shall be supplied with flexible fire resistant duct connections, anti-vibration

mountings on channel frames.

Axial Flow Fans:

All parts of the fan and accessories not galvanised shall be fully protected against corrosion

to the satisfaction of the Contract Administrator by applications of a works primer.

Fans shall be statically and dynamically balanced at manufacturers works within the design

operating speed range.

Fans shall be capable of giving the specified performance when tested in accordance with

B.S. 848-1:1997. The Contractor shall provide sound power level spectrums and constant

speed fan characteristic curves should they be required by the Contract Administrator. Upon

receipt of approvals of air handling plant and workshop ductwork drawings the Contractor will

be required to re-calculate the final system resistance prior to ordering the fans.

For mounting in ducted systems the fan casings shall be arranged to cover the overall length

of motor and impeller, and shall be constructed from heavy steel plate galvanised after

manufacture. An inspection door sited to allow convenient access to the driving motor shall

be provided, or alternatively the fan casing may be arranged to pivot. The flanges at either

end of the fan shall be of heavy gauge steel drilled to accept a matching flange and

galvanised after manufacture.


Fan blades shall be of aerofoil section with adjustable pitch angle rigidly held in a spun steel

or die cast aluminium alloy hub, fabricated mild steel or moulded glass fibre re-enforced

polyester resin.

Motors shall be of the 3 phase squirrel cage induction type, totally enclosed, Class E

insulated being suitable for continuous operation in ambient temperatures up to 40 deg.C

(104 deg.F). Motor bearings may be of the ball or roller type fitted with lubricators extended

outside the fan casings.

Fans shall be provided with an electrical terminal box on the casing, suitable for flexible

conduit entry, manufactured from heavy gauge mild steel and galvanised after manufacture.

Axial flow fans driven by an externally mounted motor shall have twin ball or roller bearing

mounted steel impeller shaft with lubricators extended externally to the fan casing.

Adequate serving doors shall be fitted for access to the belt driven and impeller shaft pulley

and the belt tunnel shall be properly sealed within the fan casing to prevent air leakage. Belt

tensioning shall be carried out by adjustment of the external motor mounting platform and

the belt and external pulleys fully guarded.

2.71 FLEXIBLE CONNECTIONS

Flexible connections shall be fitted to the suction and delivery connections of all fans and all

grilles and diffusers located in demountable ceilings. The minimum length of any

connection, shall be 50 mm and in no case shall exceed 250 mm in length. Connection to

grilles or diffusers to have a minimum length of 1 mtr, to a maximum of 2 mtrs.

Connection shall have a fire penetration time of at least fifteen minutes when tested in

accordance with B.S. 476-24:1987.

Rectangular connections shall be made from quality high grade super fine woven glass fibre

cloth lined with an impermeable lining applied by vacuum diffusion. Inlet connections shall

be made with lapping joint held by removable fixing bands and discharge joints by a 5 mm

thick mild steel flat flange.

The flexible connections shall be of the full cross-sectional area of the mating fan

connection. The ends of the ducts and fan connection shall be in line.

Where indicated to prevent noise breakout, flexible fan connections shall be of the

"Revertex" type.

Flexible connections shall consist of, or be protected by, material having a fire penetration

time of at least fifteen minutes when tested in accordance with B.S. 476-24:1987. The

material shall be of the glass fibre cloth type, canvas will not be accepted.

The width of the joints from metal edge to metal edge shall not be less than 50 mm and not

more than 250 mm.

2.72 NOISE AND VIBRATION

The Contractor shall use the services of an acoustic specialist to advise on design and

installation of all noise and vibration attenuating equipment. Particular attention shall be paid

to noise and vibration emanating from plant and equipment.

All necessary precautions shall be paid to noise and vibration entering the occupied areas

above the design levels specified.

All plant and equipment shall be adequately isolated from the building structure by the use of

anti-vibration mountings and flexible pipe and duct connections. Pipe work and ductwork

adjacent to vibrating equipment shall be supported from spring type hangers.


Attenuators shall be fitted to supply and extract ductwork to ensure that noise levels

specified are not exceeded with the plant operating at full and minimum load conditions.

Insulation shall be applied to ductwork on the system side of attenuators to prevent airborne

noise from re-entering the ductwork system where the attenuator cannot be built into

plantroom walls.

Attenuators shall be fitted to all outside air intakes and discharges including natural vents to

the boiler room to prevent noise pollution of the surrounding areas. Special attention shall

be given to noise and vibration emanating from the air cooled condensers.

2.73 REFRIGERANT PIPEWORK AND FITTINGS

All refrigerant pipe work used in VRV or split system shall be installed strictly in accordance

with the manufacturers recommendations.

Pipe work for refrigerant systems shall be of copper pipe and shall be of refrigeration quality

to BSEN 12449:1999, fully annealed (up to and including 7/8" OD only) and internally

degreased and cleaned.

The minimum acceptable pipe wall thickness shall be in accordance with Table 5 of the

British Standards.

REFRIGERANT PIPEWORK:

OD in 1/4 3/8 1/2 5/8 3/4 7/8

Wall Thickness 0.036" 0.040"

Condition FULLY ANNEALED

CD ins 11/8 1 3/8 1 5/8 2 1/8 2 5/83 1/8 3 3/8 4 1/8

Wall Thickness 0.048" 0.064"

Condition HALF HARD

REFRIGERANT PIPEWORK FOR USE WITH REFRIGERANT R410A

Minimum Thickness Of Annealed Copper Pipes

Nom Dia Outside Dia (mm) Thickness (mm)

1/4” 6.35 0.8

3/8” 9.52 0.8

1/2” 12.70 0.8

5/8” 15.88 1.0

Joints in copper pipe shall be flanged, flared (up to ¾" OD (15 mm) only), or brazed (with or

without capillary fillings). Brazing shall be carried out to the requirements of the HVCA Code

of Practice - Brazing and Bronze Welding of Copper Pipe and Sheet.

Screwed joints will not be accepted in refrigerant pipes except on the equipment

accessories. In such cases the threads shall either be of taper form and used in conjunction

with PTFE tape or an anaerobic sealant or of parallel form associated with machined join

faces and a suitable joint compound.


Plastics pipe with compression fillings will be accepted for feed piping to control cabinet door

mounted pressure gauges and similar fittings. The grades of pipe used shall withstand the

test pressure applied and the effects of refrigerant and oil. Plastics pipe will not be accepted

for any other refrigerant pipe work.

Compression fittings will not be accepted on refrigerant pipe work except as detailed above

and on equipment accessories using Refrigerant 11,113 or 114.

Refrigerant pipe work shall not be arranged for running compressors in parallel (i.e. with

common suction and/or discharge pipes). The use of a number of compressors, each having

an independent refrigerant circuit in a common evaporator will be permitted providing

pressure tests between adjacent refrigerant circuits in the evaporator are carried out during

manufacture.

The pipe work shall be designed so that oil in the refrigerant leaving the compressor (and

passing any oil separator filled) shall be carried through the system and back to the

compressor at the lowest stage of capacity unloading.

Pipe work shall be firmly supported and secured to minimise vibration. Vibration eliminators

shall be filled to the compressor suction and discharge pipes to minimise transmission of

vibration of noise. Where indicated, a gas pulsation damper shall be fitted in the refrigerant

discharge pipe, in the plantroom, as close as possible to the refrigeration compressor.

After completion the refrigerant pipe work shall be pressure tested as detailed in the

Specification.

Pipe work shall be reamed after culling and shall be free from burrs, scales and other defects

and shall be thoroughly cleaned before erection. At all times during the installation of the

pipe work the Contractor shall keep all ends capped except when actual jointing is taking

place and all pipe work shall be kept sealed prior to installation.

Joints are to be thoroughly cleaned to bare metal before being brazed with cuprotectic or

silver solder. Flux used for silver solder joints shall not contain ammonia, which is harmful to

copper. Whilst pipes are being brazed dry nitrogen is to be passed through the tube at a

velocity sufficient to displace the air within the tube.

Horizontal and vertical pipe runs shall be supported on heavy quality galvanised cable trays

and shall be clipped and bracketed at 3 metre centres maximum and vertical pipe runs at not

more than 4 metre centres. Vertical suction pipe work shall have oil traps at 4 metre centres.

Flexible pipes of the anaconda type shall be installed on all connections to air cooled

condensers. Elbows shall not be permitted. Only long radius elbows shall be used.

To ensure that no oxides have formed in the pipe lines after completion of all the pipe joints,

but before testing, three brazed joints will be selected at random by the Contracts

Administrator or his representative.

The joints selected will be cut through by the Contractor and examined by the Contract

Administrator.

If oxides are found in a joint all pipe lines shall be replaced at no extra cost to the Contract.

After examination all joints cut open shall be made good at the Contractor's expense.

During the whole of the pipe jointing operation the Contract Administrator or his

representative shall be in attendance.

Every refrigeration system shall be protected by a pressure device unless it is so constructed

that pressure due to fire conditions would be safely relieved. The equipment provided shall


Comply with BSEN 378 Parts 1-4:2000 and the outlet piped to discharge outside the building

if bursting discs are used.

A liquid receiver shall be filled to any system using an air-cooled or evaporative condenser.

For systems 70 kW and above, having a water-cooled condenser with insufficient capacity to

take the complete refrigerant charge, a liquid receiver shall be provided to make up the

deficiency.

Systems using a thermostatic expansion valve shall have the following items preceding it in

the refrigerant liquid pipe:

a. A solenoid valve.

b. A sight glass.

c. A refrigerant drier (replacement).

d. A refrigerant strainer.

e. A capped refrigerant charging valve.

An evaporator pressure regulating valve, where filled, shall be protected by a strainer and an

evaporator pressure gauge shall be provided up-stream of the valve, fitted with means of

isolation.

Units having a direct expansion evaporator at a higher level than the compressor shall

operate on a pump down cycle.

Refrigerant stop valves which incorporate a spindle gland shall be of the back seat type. The

spindle gland shall be serviceable with the valve 'in situ'.

All compressors shall be provided with oil failure control or protection. Each refrigeration

machine shall be provided with thermostatically controlled crankcase heater(s) to ensure that

all components of the compressor(s) may be properly' lubricated when the compressor(s)

start. The operation of the compressor(s) should be interlocked with the crankcase heater(s)

to prevent operation until correct oil temperature has been reached.

The crankcase heater(s) shall be provided with an uninterrupted power supply to maintain

the temperature at the correct temperature with the machine off but not isolated to provide

prompt restart.

Oil cooling may be provided by direct refrigerant injection with hot gas returned to the

evaporator. The system shall be automatically controlled as an integral part of the

refrigeration machine controls system.

Each separate circuit of each refrigeration machine shall be provided with the following

instrumentation:

Discharge pressure gauge, Suction pressure gauge and Oil pressure gauge.

All gauges shall be removable without interruption of the machine operating by provision of

gauge cocks - sensor pockets.

Each refrigeration machine shall be provided with a controls panel incorporating all controls

and indicators necessary for machine operation. The panel shall incorporate starters, circuit

breakers, step controllers, pressure switches, flow switches, temperature sensors, etc., and

be complete with door interlocked main isolator.

Access doors shall be hinged and lockable giving access to all items of equipment.

The entire installation shall be arranged for safe and full access, for all routine service and

maintenance and also for all plant equipment.


2.74 EQUIPOTENTIAL BONDING

The following services shall be bonded to the main earthing terminal by means of cupinned

lugs, nuts and bolts and labelled to denote size and destination:

a. Incoming gas service

b. Incoming water service

c. Pipe work within plant rooms ducts and risers

d. Ductwork within plant rooms distribution and risers

e. Fire hydrant services or dry riser

f. Each side of pipe or duct with non metallic joint or flexible connection

g. Intake room switchgear/panels and other earth bars

h. All items of plant and equipment tanks, cylinders, calorifiers, boilers vessels flues and air handling units etc

All in compliance with the current BS 7671 and part P of the building regulations.

2.75 MILLENNIUM COMPLIANCE

All items and equipment provided for these works must conform to the requirements of the

British Standards Institution PD2000-1: 1998 in respect of Millennium compliance (also

sometimes known as century or Year 2000 conformity) and must meet the following

definition.

THE DEFINITION

Year 2000 conformity shall mean that neither performance nor functionality is affected by

dates prior to, during and after the year 2000.

In particular:

Rule 1: No value for current date will cause any interruption in operation.

Rule 2: Databased functionality must behave consistently for dates prior to, during and after year 2000.

Rule 3: In all interface and data storage, the century in any date must be specified either explicitly or by unambiguous algorithms or inferencing rules.

Rule 4: Year 2000 must be recognised as a leap year.

2.76 OPERATING AND MAINTENANCE MANUAL

In compliance with the Health and Safety at Work Act 1974 the persons in charge of the

building or appointed representatives of the Client shall be instructed in the correct

operation, control and maintenance of the systems and components.

Operating and Maintenance Instructions, purpose written for these particular works in

accordance with the BSRIA Guide BG 1/2007 “Handover operating and Maintenance

Manuals and project feed back” shall be provided. The manuals shall be based on the Class

‘D’ standards and be divided into the following sections:

Introduction/Format of the Manual:

Section 1 How to use the Manual

Section 2 Contractual and legal guides

Section 3 Design intent/parameters

Section 4 Description of systems

Section 5 Schedule of systems


Section 6 Spare parts

Section 7 Spares policy

Section 8 Commissioning data

Section 9 Operation of systems

Section 10 Maintenance and fault finding

Section 11 Modification information

Section 12 Disposal instructions

Section 13 Names and addresses of manufacturers

Section 14 “As Installed” drawings

Section 15 Emergency information

Section 16 Manufacturer’s literature

Particular attention must be given to detailing the controls strategies, control set points,

maintenance schedules (every day, every week every month, every three months, every six

months, every year etc). Manufacturer’s maintenance publications must be included in the

manuals.

Three complete sets of the approved instructions secured inside good quality hard cover ring

binders of adequate size shall be produced and made available at Practical Completion of

the works. Two sets shall be handed to the Client and one set issued to the CDM-C for

inclusion in the health and Safety File.

The installations will not be accepted by the client until the approved manuals have been

provided.

2.77 RECORD DRAWINGS

The Contractor shall keep a record as the work proceeds of any work installed not in

accordance with the drawings. On completion of the works, the Contractor shall submit a set

of drawings showing the works as installed to the engineer for comment/approval. The

drawings are to show the exact position of all apparatus pipe work, valves etc., together with

diagrams, schedules etc.

After approval of the drawings one complete set of prints shall be provided and included in

each Operating and Maintenance Manual and a CD/DVD of the drawings (Auto CAD DXF

File) be supplied to the engineer for retention.

The words “Record Drawings” shall be clearly indicated on all drawings adjacent to the title

corner.

General layout drawings must be to a scale of not less than 1:50.

For plant/boiler rooms one copy of schematic and valve chart schedule shall be laminated

and installed on an internal wall, once checked by the contracts administrator prior to

handover.

SECTION THREE

PARTICULAR SPECIFICATION – MECHANICAL AND ELECTRICAL SERVICES

3. SECTION THREE ................................................................................................................................. 1

PARTICULAR SPECIFICATION – MECHANICAL AND ELECTRICAL SERVICES ............................ 1

3.1 INTRODUCTION: .................................................................................................................................. 1

3.2 SCHEDULE OF DRAWING: ................................................................................................................. 2

3.3 HEALTH & SAFETY ASPECT OF THE WORKS: ................................................................................ 2

3.4 HEALTH & SAFETY FILE: .................................................................................................................... 3

3.5 DESCRIPTION OF SERVICES TO BE PROVIDED: ............................................................................ 3

3.6 GENERAL REQUIREMENTS: .............................................................................................................. 4

3.7 EXISTING MECHANICAL SERVICES: ................................................................................................. 5

3.8 REMOVAL OF EXISTING PLANT AND SERVICES: (PHASES ARE INDICATIVE) ........................... 7

3.9 SCOPE OF WORKS: ............................................................................................................................ 8

3.10 TEMPORARY HEATING SYSTEM: .................................................................................................... 10

3.11 PROPOSED MECHANICAL SERVICES: ........................................................................................... 11

3.12 PROPOSED HOT WATER INSTALLATION DISTRIBUTION & IN DWELLINGS .............................. 15

3.13 EQUIPMENT SELECTION – MECHANICAL ...................................................................................... 16

3.14 BOILERS ............................................................................................................................................. 17

3.15 BOILER FLUE SYSTEM ..................................................................................................................... 18

3.16 BOILER ROOM VENTILATION .......................................................................................................... 18

3.17 HEATING LTHW PUMPS ................................................................................................................... 18

3.18 PUMP ANTI-VIBRATION MOUNTINGS AND FLEXIBLE CONNECTIONS ....................................... 19

3.19 PRESSURISATION UNIT ................................................................................................................... 19

3.20 COMBINED LLH AIR AND DIRT SEPARATOR ................................................................................. 19

3.21 DOSING EQUIPMENT ........................................................................................................................ 19

3.22 PRESSURE AND TEMPERATURE GAUGES ................................................................................... 20

3.23 THERMOMETERS .............................................................................................................................. 20

3.24 STRAINERS ........................................................................................................................................ 20

3.25 VALVES ............................................................................................................................................... 20

3.26 COLD WATER (PLANTROOM) .......................................................................................................... 21

3.27 COLD WATER IN SUB PLANT ROOMS ............................................................................................ 21

3.28 COLD WATER SUPPLY TO DWELLINGS ......................................................................................... 21

3.29 COLD WATER SUPPLY GENERALLY .............................................................................................. 21

3.30 GAS VALVE ........................................................................................................................................ 22

3.31 PIPEWORK MATERIAL ...................................................................................................................... 22

3.32 UNDERGROUND PIPEWORK LEAK DETECTION SYSTEM ........................................................... 25

3.33 LEAK FAULT LOCATOR PANEL (FULL MONITORING WITH READOUT) ...................................... 25

3.34 WORK WITHIN TRENCHES ............................................................................................................... 26

3.35 RADIATORS ........................................................................................................................................ 26

3.36 CONTROLS ......................................................................................................................................... 27

3.37 ELECTRICAL REQUIREMENTS FOR MECHANICAL SERVICES ................................................... 37

3.38 BONDING ............................................................................................................................................ 44

3.39 SYSTEM PERFORMANCE TESTS .................................................................................................... 44

3.40 SYSTEM CLEANING AND FLUSHING OUT ...................................................................................... 44

3.41 TESTING, COMMISSIONING AND PUTTING TO WORK ................................................................. 45

3.42 BUILDERS WORKS ............................................................................................................................ 46

3.43 THERMAL INSULATION ..................................................................................................................... 47

3.44 OPERATING AND MAINTENANCE MANUAL (RECORD DRAWINGS) ........................................... 49

3.45 MAINTENANCE OF SYSTEMS .......................................................................................................... 50

3.46 SPARES .............................................................................................................................................. 50

3.47 DEFECTS PERIOD: ............................................................................................................................ 50

3.48 ASBESTOS ......................................................................................................................................... 50

3.49 ELECTRICAL WARM AIR HEATERS ................................................................................................. 50

3.50 SCHEDULE OF EQUIPMENT .............................................................................................................. 1

Z:\WP\DMP\JOB\DMP\6658\Spec\H Section 3 Mech & Elec Particulars.docx 1

3. SECTION THREE

PARTICULAR SPECIFICATION – MECHANICAL AND ELECTRICAL SERVICES

3.1 INTRODUCTION:

The project as a whole is predominately a Mechanical lead project and as such the

Mechanical Contractor shall be Principle Contractor throughout these works.

The Meakin Estate consists of a main plant room with four sub plant rooms that distribute

heating, hot and cold water to eight dwelling blocks consisting of 123 variously sized

dwellings and a TRA Hall.

The project consists of the replacement in three phases of the main plant room and four sub

plant room equipment, the underground distribution pipework, plus the pipework distribution

around the block to the dwellings along with the heating and hot systems within the

dwellings. Temporary plant will be required throughout the project to the heating and hot

water services working during all phases.

The phases for the works consist of installation of temporary plant, replacement of the main

plantroom and the four sub plant rooms along with the underground heating mains between

as first phase. The second phase consists of the installation of the new distribution heating

and hot water pipework around the blocks from the four sub plantrooms to all the dwellings

and TRA Hall. Whilst the final phase consists of the replacement within the dwellings and

TRA Hall of the heating system and the hot water pipework system, along with the removal

of the old block distribution pipework from sub plantrooms to dwellings.

The estate’s address is Meakin Estate, Decima Street, London SE16 in the London Borough

of Southwark (LBS). The estate is run by a Joint Management Board (JMB) with

Leathermarket JMB as the principal client and LBS the landlord.

The complete existing heating and hot water system is being replaced due to it being beyond

its economic life expectancy for repair’s and the equipment no longer being supported by the

manufacturers in some instances.

The whole estate is fed from standalone main plant room (with adjacent gas incoming meter

room) this main plant room serves via a set of primary heating flow and return underground

mains, four sub plant rooms within the blocks.

The works contained within this specification relate to the service within the Meakin Estate

Complex

Meakin Estate is generally split into eight housing blocks with the blocks 1 and 2 contain

dwellings 1-23 inclusive made up of ground floor flats, first floor flats and second floor

marionettes. Block 1 also contains a secondary sub plant room No. 1 on 1st floor level.

Blocks 3 and 4 contain dwellings 24-51 inclusive with the same dwelling arrangement plus

an existing sub plant room No. 2 on 1st floor level of block 3.Block 5 contains dwellings 52-

66 inclusive and has a sub plant room on the first level. Block 6 contains dwellings 67-89 and

the TRA hall. Block 7 contains dwellings 90-107 and has a sub plant room on the first floor.

Block 8 contains dwellings 108- 123.

The sub plant rooms feed all the dwelling as follows:

Sub plant room 1 – Blocks 1&2 No’s 1-23

Sub plant room 2 – Blocks 3&4 No’s 24-51

Sub plant room 3 – Blocks 5& part of 6 No’s 52-66 and 67-78 and the TRA hall

Sub plant room 4 – Blocks part of 6,7&8 No’s 79-123


The area is within the congestion zone and a controlled parking area that is paid via street

meter at hourly rate in the surrounding streets. Parking is possible during the controlled

hours of 09.00 – 17.00 Mon – Fri by payment of the appropriate fee at a parking meter.

There is no off street parking available.

3.2 SCHEDULE OF DRAWING:

TITLE. DWG No.

EXISTING MAIN PLANT ROOM SCHEMATIC M 100

EXISTING SUB PLANT ROOMS SCHEMATIC M 101

NEW HEATING & DOMESTIC SCHEMATIC - PART 1 M 102

NEW HEATING & DOMESTIC SCHEMATIC - PART 2 M 103

NEW UNDERGROUND MAINS & SECONDARY

DISTRIBUTION M 104

TYPICAL PLOT TYPE A - 1 BED FLAT LAYOUT M 105

TYPICAL PLOT TYPE B - 1 BED MAISONETTE

LAYOUT M 106

TYPICAL PLOT TYPE C - 2 BED FLAT LAYOUT M 107

TYPICAL PLOT TYPE D - 2 BED MAISONETTE

LAYOUT M 108

TYPICAL PLOT TYPE E - 3 BED FLAT LAYOUT M 109

TYPICAL PLOT TYPE F - 3 BED MAISONETTE

LAYOUT M 110

TYPICAL PLOT TYPE G - 4 BED MAISONETTE

LAYOUT M 111

3.3 HEALTH & SAFETY ASPECT OF THE WORKS:

The Contractor shall comply fully with the requirements of Health & Safety Rules. The

scheme will fall within the Scope of the Health & Safety CDM Regulations. The following

outline information regarding risk assessment is available:

a. Works within a confined space within plant room areas and new manholes in the modification of pipework is required.

b. Works within a confined space within manholes, service voids, ducts and trenches in the modification of pipework are required.

c. Working at height and risk of falling objects and personnel.

d. Working within environment of hot surfaces.

e. Working within confined space and risk of injury to personnel and fire hazards whilst carrying out “hot works”.

f. Working within dust-laden areas and protection of same.


g. Risk associated with craneage, hoisting and manhandling heavy plant and equipment to working areas to be considered.

h. Risk associated with the use of burning equipment and hot works.

i. Works on existing electrics is required.

j. Works on existing (water filled) pipework is required.

k. Works on existing lagging (i.e. loose fibres) is required. (Needs to be checked with clients’ asbestos register).

l. Works on asbestos, if found, shall be confirmed to the client who will arrange for its removal etc.

m. Works within confined roof spaces and balconies in modification of plant and pipework is required.

3.4 HEALTH & SAFETY FILE:

The Contractor shall prepare and compile the Health and Safety File and forward it to the

Client’s Representative for comment. For the purposes of this project the Mechanical

Contractor appointed shall act as ‘The Principal Contractor’ and the Contractor shall liaise at

all times with the Client’s Representative. The File shall be available on site and forwarded

in draft form two weeks before practical completion of the project and any comments

incorporated within a further two weeks of those comments being received. The File shall

then be re-submitted to the Client’s Representative.

Upon receiving agreement to its content one copy shall be bound or otherwise assembled

within a ring binder(s) and another, in electronic format, shall be forwarded to the Client’s

Representative.

Information contained in the file is to be relevant to the project executed and needs to

include that which will assist persons carrying out construction and installation work on the

structure at any time after completion of the current project and may include:

a. Record or ‘as built’ drawings and plans used and produced throughout the construction process along with the design criteria (original specification and design drawings).

b. General details of the construction and installation methods and materials used.

c. Details of the structures and installations equipment and maintenance facilities.

d. Maintenance procedures and requirements for the structure and installations.

e. Manuals produced by specialist contractors and suppliers which outline operating and maintenance procedures and schedules for plant and equipment installed as part of the structure.

f. Details of the location and nature of utilities and services, including emergency and fire-fighting systems.

g. An index of the file’s contents and a short introduction generally outlining the works of the current project.

h. Contain details of significant hazard that effect health and safety.

Whilst the H & S File contains O & M manuals and record drawings this does not relieve the

Contractor of the requirement to provide them separately as required elsewhere in this

specification.

3.5 DESCRIPTION OF SERVICES TO BE PROVIDED:


The Contractor shall be responsible for the correct installation and the proper working of the

completed installations that comprise of the works. In addition to the complete and proper

installation of the works, the Contractor shall be responsible for:

Please note that the following may be required for each phase and the Contractor must

make due allowance:

a. Preparation of all working drawings and schedules, risk assessments and method statements shall be issued and commented upon before installation works commence.

b. Attending meetings with the client’s representative and / or their representative.

c. Supply of all plant, equipment, materials and labour.

d. Taking delivery, unloading, handling, temporary storage and protection of all plant equipment and materials.

e. Providing all specialist plant, equipment and tools necessary for erection and testing.

f. Installing and connecting all plant and equipment and ensuring that all associated work such as builders work, etc. is properly executed.

g. Demonstrating that the complete installation is capable of the performance and method of operation specified.

h. Commissioning and testing the complete installation including making adjustments, calibrating, etc., as necessary and making arrangement to enable the client’s representative to be present during such commissioning and testing etc.

i. Providing maintenance instructions and complete sets of “As Installed” drawings of the complete installation.

j. Production of throughout and after project a Health and Safety file.

k. Supply and handover at the time of practical completion, air cock, drain cock keys and any other items specified as being required.

l. Instructing Client’s staff in the operation of the installation.

m. Provide a user booklet for each dwelling on operation of new system.

n. Maintaining and keeping the installations in full working order and making good all defects or other faults during the specified periods.

3.6 GENERAL REQUIREMENTS:

The Tenderer’s are advised to visit the site to properly assess their tenders, no additional

costs at a later date will be entertained by the Leather market JMB Project Engineer, for

claims associated with site familiarity. Access needs to be arranged via the Leather market

JMB Project Engineer

The contract period shall be 30 weeks (4 weeks mobilisation period followed by 26 weeks on

site). The anticipated commencement date for the Phase 1 installation is in early June 2016.

The completion date is to be mid December 2016 with an anticipated heating back on to the

blocks by 1st October 2016.

The Contractor should make all due allowances in his tender for weekends, bank holidays

and all ‘out of hours’ working deemed necessary to complete the project on time and must

be agreed with clients representative prior to commencement.

The site will require partial closure of road way & full closure of paved area arranged by

contractor for delivery & removal of equipment along with access to & from plant room (via

scaffolding) by site operatives. The area is to be closed off and secured by Heras type

fencing. However access to dwellings etc. must be available at all times.

The site welfare & storage facilities also need to be provided by contractor in location shown

on site plan drawing.


The Contractor shall submit with his tender a brief “Method Statements” for all three phases

to illustrate how the installation sequence of works, including temporary heating and

scaffolding, will be achieved within the designated program periods and fully price all the

sections of the Pricing Document, including any alternatives. These statements must be

finalized prior to commencement on site.

The contractor will ensure that throughout the project that access for emergency services are

maintained at all times.

All works will be carried out in accordance with the Leather market JMB relevant Safety

Regulations, which may be seen by request to the Leather market JMB Project Engineer

The installation(s) will comply with all the relevant statutory authorities and regulations and in

particular with the following:-

1. The Current IET Regulations for the Electrical Equipment of Buildings 2. Regulations under the Factories Acts 3. Regulations under the Electricity Acts 4. The Gas Safety (Installation & Use) Regulations 5. The Health & Safety at Work Act 1974 6. Any Special Regulations issued by the Local Electricity Gas or Water Undertakings 7. The Control of Pollution Act 8. Control of Substances Hazardous to Health Regulations (COSHH) COSHH

Regulations 9. The New Water Regulations 10. Gas Safe Regulations 11. All Relevant British Standards and Codes of Practice.

3.7 EXISTING MECHANICAL SERVICES:

3.7.1 Main Plant Room

The heating and hot water to the estate is provided by a communal heating system

consisting of two gas fired Thompson Cochran Calpac (1172 kw output) boilers circa 40

years of age, that provides the primary heating water which is distributed to sub plant rooms

via communal circulation mains. The boilers are each fitted with twin type safety valves, gas

booster sets that serve their Nuway burners circa 20 years of age and roof mounted flue

dilution fans (38”Ø CB Woods axial type) circa 30 years of age, along with fresh air intake

fan which does not appear to enter the plant room, a new pump, the new pump serves the

primary circuit along with a Armstrong system pressurisation unit and 3200lt expansion

vessels made up of four vessels to provide the pressure and expansion for system.

Within the main plant room there is a GMI Detector System of sensors and control panel, a

C&C instalect control panel, with adjacent JEL BMS System, fire alarm panel, water

softener, dosing and sampling and three phase electrical supply.

Generally, the pipework, valves, plant are circa 40 years of age and has regular failures as

demonstrated by the outage reports within the log book and residential dissatisfaction with

the lack of heating and hot water.

Underground Mains

From the boiler plant room a pair of 150mm (6”) primary heating circulation flow and return

mains run underground to serve the four sub plant rooms. Each sub plant room has a 100Ø

flow and return entry into ground floor that rises to first floor before dividing into heating and

hot water supplies.

The existing buried pipe work is 30-40 years old and has reached the end of its economic life

expectancy.


The pipe work routes run from the main plant room and supply the four satellite sub plant

rooms on the estate. Please see tender drawings for more details.

Gas

The current gas is provided to the main plant room from the separate gas meter room

adjacent to plant room and feeds the existing boilers via individual gas booster sets

incorporated into each boiler with shut off valve within gas meter room.

Electrical system

The electrical system within main plant room is via an existing 400v/3ph intake supply

adjacent to the entrance door which serves all the equipment, supplies of lighting within the

main plant room.

3.7.2 Four Satellite Plant Rooms

Within each of the four sub plant rooms the primary heating firstly serves the secondary

heating run and standby pumps via 3 port control valve that in turn provide heating to the

blocks (or part block) dwellings via secondary heating flow and return pipework. The primary

circuit also splits and serves separately the hot water shell and tube calorifiers via 3 port

control valve. This calorifier has two hot water flows from the top that both leave the plant

room at high level. Finally the calorifiers are fed with cold water assumed from roof top

tanks. There is also a cold water main that passes through each sub plant room and

distributes to dwellings for cold water supplies, following same routes as heating and hot

water.

Distribution Pipework

Leaves the sub plant room at high level and distributes heat to each dwelling via the

underside of the balconies [assumed to serve ground from high level underside of balcony

first floor and first from high level underside balcony second floor whilst second from low

level underside balcony second floor] that are situated at the front of each dwelling. Each

serve part of the dwellings within sub plant room area with hot water via same route as

heating. The return hot water however returns via same route into plant room via a common

return that is connected to the calorifier at low level via secondary single hot water circulation

pump. Please note these tanks will need to be inspected and replaced, if it is found that a

tank is new then on agreement with the CA it can be left in place and renewed.

Each sub plant room is fitted with new (within 2 years) control panel.

Within the existing four sub plant room the calorifiers, valves, pipework are circa 40 years of

age. The pumps are generally 15 – 20 years of age.

Four Plant Room Electrical systems

Each sub plant room also has an incoming supply of 3 phase 400volt located behind

doorway in each sub plant room which again serves all the power and lighting within the sub

plant room and possibly the landlords supplies.

The control panels are wall mounted to the four sub plant rooms and are all installed circa 2

years old. The control system has not been fully integrated with the heating and hot water

system. Generally, only temperature and pressure sensor have been fitted which can be

visually seen on the BEMS control system.

3.7.3 Indwelling

Within each dwelling the heating flow and return enters from balcony area into internal

cupboard where control valves are located before it runs and distributes to serve a range of

wall mounted radiators whilst the hot flow and return along with the cold water and enter in


each dwelling via same cupboard where it distributes water to all necessary outlets in

bathroom, toilet and kitchen.

Control of the radiators is via Thermostatic Radiator Valves situated in each radiator.

The hot water calorifiers provide hot water at 60ºC for circulation around the block and are

controlled within sub plant rooms by hot water thermostats on the calorifiers.

Generally circulation appears to be regulated by use by balancing valves within the

secondary circuits (where fitted).

The radiators, valves and pipework are generally 30 to 40 years of age and are at various

stages of dilapidation.

Access

Access to main plant room is good via double opening doors to a paved area adjacent to the

car park, with hedge row and planting area between. The doors have a step up about

400mm & layout within is generally good except for the loose floor meshing that has been

installed over the sump pump and where the pipes go underground & leave the main plant

room.

Adjacent to the main plant room is a car park area that may be utilized to gain access for

deliveries and if possible with suspension of car parking site office/welfare facilities and

location of temporary plant etc. should this be required.

The secondary plant room’s access to existing rooms is difficult as it is within the door entry

system & up two flights of stairs with direct access to the plant room off of the communal first

floor covered balcony. Access to the areas below plant room (which may be used for

replacement equipment during project) is again through door entry system but direct off this

lobby is the plant room.

Access to the existing tanks is assumed to be via external ladders off of 2nd floor balcony

into roof space.

3.8 REMOVAL OF EXISTING PLANT AND SERVICES: (PHASES ARE INDICATIVE)

The contractor will be required to carry out the following - Note: All temporary boilers and

associated works are to be in place and all systems to be isolated & made safe prior

to any the strip out works commencing:

3.8.1 Phase1

a. All temporary plant installed and commissioned. This will require 4 No: temporary boilers, one for each sub plant room. These are to be connected into the secondary flow and return for heating and the flow and return for the calorifier in each sub plant room.

b. Existing Flues System, Isolate and strip out and remove from site the flue system and the redundant boiler flues. Note: the existing combustion ventilation louvres to be retained for the boiler room ventilation.

c. Existing Boilers Power and Controls, Strip out and remove from site the existing HVAC control panel, power supplies, containment and field devices when made redundant by the new works.

d. Existing Gas, Strip-out the redundant sections of gas pipe within plant room including existing gas solenoid valve and gas boosters.

e. All Redundant Piping, valves & fittings, pressurisation system, circulation pumps, LTHW flow & return headers, open vents & cold feeds [back to tank] are to be stripped-out and removed from site when made redundant by the new.


f. Once the temporary system is up and running and all old plantroom equipment has been removed the Contractor is to provide new boilers, complete with safety valves, gas supply, water supply, electrics supply, new flue system, and new controls system, plus all necessary auxiliary services such as pressurisation pumps, pipe valves, fittings and insulation etc.

g. Once all new main plant room is up and running the Contractors shall provide new underground mains from main plant room to the four sub plant rooms. These shall be tested ad left filled ready to use.

h. Following these new mains the Contractor shall then link the temporary system to the new mains and cold mains and replace plant and equipment in each sub plant room one at a time. Please note downtime for these shutdowns shall be kept to a minimum, hours rather than days.

i. Once all four new sub plant rooms are up and running with new mains and temporary plant room the Contractor, shall switch the temporary plant room back to the main plant room.

This shall conclude Phase 1.

3.8.2 Phase 2

a. Install underground mains to all sub plant rooms, this pipe work is to be taken into the sub plant rooms and terminated with isolating valves. It is to be flushed, tested and chemically treated and left primed ready for phase three.

b. At this point the existing heating can be dis-connected; the hot water services must remain throughout. The existing heating pipes to each flat will be stripped out and the new hot water pipe to go back in its place, once this has been completed to all the dwellings on each system then the temporary plant will be connected to the new hot water distribution pipe and each dwelling in turn will be switched over to the new hot water pipe. It may well be necessary for the temporary plant to be connected to the new and existing hot water system during the changeover.

c. Once all the flats are the new pipe work that will be fed by the temporary boilers then phase 2 is complete.

This concludes Phase 2.

3.8.3 Phase 3

a. The sub plant rooms can now be stripped out along with all the existing hot water distribution pipe work.

b. The new sub plant room systems are to be installed. The new CWST’s are to be installed along with new cooling tanks for the open vent from the hot water system. All heating distribution pipe work is to be installed to each dwelling.

c. Indwelling heating and hot water systems. Within dwelling and TRA Hall shall be isolated, drained down, strip out all pipe work, radiators, valves and fittings, removed from site on one dwelling at a time basis and new systems installed. Once complete dwellings shall be switched from old distribution system to new.

d. Redundant Materials, All redundant plant and fittings to be disposed from site by the contractor through the approved sources.

The stages are designed to minimise the disruption to the tenants, all shutdowns must be arranged through the CA. The shutdowns must be kept as short as practically possible, hours not days.

3.9 SCOPE OF WORKS:

For the purpose of this project the Mechanical Contractor shall be the Contractor as defined

under the Construction (Design and Management) Regulations 2015.


This specification and any associated tender drawings cover the disconnection and removal

of existing mechanical and electrical services and the supply, delivery to site, erection,

installation, testing and commissioning of all new mechanical and electrical services, all

associated builders work, including all materials and equipment specifically called for or

implied as necessary, including the use of all skilled and unskilled labour necessary for the

complete installation of the mechanical and electrical services installations within the plant

rooms, tank rooms, and risers.

All temporary works, connections, re-connections, draining, refilling and general

maintenance and operation of the mechanical and electrical services during the contract

period, whether specifically called for or implied, and all final testing, regulation and

commissioning details are handed over by the mechanical and electrical Contractor ready for

immediate use shall also be included.

The following items shall at least be included:

a. The contractor is to control the project accordingly, acting as the Principal Contractor in control over all works, through sub contract orders (builder’s works, mechanical, electrical, controls & temporary etc.).

b. Carry out initial site investigations to establish locations of existing plant, all necessary isolation and draining points, pipework and electrics plus confirm operation of existing pump sets as run and stand-by.

c. Carry out initial site investigations to establish locations of existing plant to be reused or removed and all necessary isolation and draining points, pipework and electrics. Along with survey of the surrounding area and riser locations prior to any excavation and or erection of risers to ensure route is understood and clear.

d. Identify any asbestos based materials, if suspected then inform client, who will arrange necessary removal etc.

e. Provide a programme of works including all shutdowns etc.

f. Carry out an internal and external sound test and acoustic DB load checks when all existing plant is running before strip out and repeat the above after the complete new installation has been completed.

g. Provide working drawings, risk assessments and method statements for all works for comment by client’s representative prior to commencing installation.

h. Erection scaffolding set up site & delivery areas along with providing a temporary heating system for operation whilst works are carried out.

i. Isolation, make safe, disconnection, draining, strip out and modify all the relevant existing mechanical and electrical services.

j. Carry out removal from site of all redundant pipework and equipment and dispose of from site.

k. Liaison with the residents for the impending works including delivery of all notification letters to residents advising of any interruption of heating and domestic hot water services.

l. Taking delivery, unloading, handling, temporary storage, protection and transportation to the work area as required all equipment and materials.

m. Installation of all temporary heating, hot water services and all associate works during duration of project

n. Installation of new mechanical and electrical services ensuring that there is minimal disruption (hours rather than days) to the heating and hot water service throughout the project period. Note that the client has allowed for the heating to be switched off for phase 2 of the project. Phase 3 will be dependent on the dwelling occupant and the weather.

o. Provide new boilers, flue and pumps etc. along with all necessary pipe valves and fittings etc.


p. Run new gas supply from inside plant room to serve the new LTHW boilers complete with pumps and a new gas solenoid valve, incorporating new emergency shut off button and three heat detectors.

q. Supply and install a new LTHW heating fill and pressurisation unit complete with expansion vessel together with interconnecting piping valves & fittings mounted on a new 100mm high concrete plinth.

r. Supply and install a new wall mounted control panel and associated field devices to provide power and BMS controls to the new heating plant. The new panel to be integrated into the Leather market JMB IT systems.

s. Renew the existing combustion ventilation in main and sub plant rooms.

t. Supply and Install new doors to each of the four satellite plant rooms. Including all locks, hinges, handles and associated builders works.

u. Provision of all associated builders work in connection, with the execution of the work, reinstatement and making good, plus the replacement as necessary of the plant room high level and low level combustion/ventilation system louvres.

v. Attending site for demonstrations in the operation of the new equipment and controls.

w. Provide new underground mains and secondary distribution services throughout site.

x. Provide new underground main leak detection system.

y. Provision of all necessary Mechanical and Electrical testing, commissioning, staff training, Operations and Maintenance, plus Health and Safety documentation for all the above works.

z. Provision of all documentations i.e.: Weld and Gas Test Certificates, Test Certificates – (hydraulics), Test Certificates underground mains etc. – (electrical), Commissioning Data, O & M Manual, Health and Safety File, Record Drawings, NDT Certificates, Alarm Certificates and Chlorination and disinfection certificates.

All the foregoing works to be carried out in accordance with this Specification, Pricing

Document and Tender Drawings.

The whole of the works shall be carried out under the direction, and to the complete

satisfaction of the Client’s Representative.

The Contractor shall allow for the necessary welfare facilities, as detailed in the main

preliminaries.

Note that the facilities must be the type that does not need to be connected to the drainage

system, as this may not be available.

Please note that on completion of the works all temporary welfare facilities and delivery

routes (internal and external) are to be removed and any grassed area, on which the site

setup is proposed to be placed, is remedied after use, this includes the surrounding grass

area for the entire project. Any pavement or object which may get damaged in the

installation, use or removal of the site setup is replaced or repaired. In any internal areas,

any damage caused is to be rectified to match existing.

Finally the site store/setup/works vehicles do not cause an obstruction to emergency

services or any parking facilities.

3.10 TEMPORARY HEATING SYSTEM:

Prior to the boiler replacement works the contractor shall supply & install 4 temporary

heating systems in a housing in the position as indicated on the site layout [or similar] to

provide heating and hot water primaries to each flat during phase 1&2 of the works. The

boiler shall have a minimum rating of 500Kw each and provide LTHW at 82/71°C Flow and

Return. The temporary plant must be able to provide hot water to all dwellings throughout

phases 1&2.


The housing is to be placed on ground within site boundary, with flow & return pipes up

outside of building (via scaffolding) into sub plant rooms to connect to existing heating

pumps and primary circuit of the high recovery HWS cylinders.

The power supply for the temporary boiler shall be run from the existing supply within the

plant room down the scaffolding [used for support to the temporary heating system.

The fuel for the temporary boilers will be supplied by the contractor it is to be LPG. The

contractor is responsible for the delivery, storage and use of the LPG.

3.11 PROPOSED MECHANICAL SERVICES:

It is envisaged that all the works to the project shall be commenced from May/June 2016 and

be completed by mid of December 2016 with a heating on date required by 1st October

2016.

The Contractor shall submit with his tender a brief “Method Statement and program” and

phasing proposals to illustrate how the installation sequence of works will be achieved as

part of their Tender return bid and is to be complete with phased changeover within the

designated programme period. The contractor shall also fully price all the sections of the

pricing document, including any alternatives. All to be agreed with Client before

commencement of works and to be included as part of the pre-construction information that

is required.

Please note this project is to be 3 stages with heat on by 1st October 2016 being stage 2

and completion stage 3 by mid December 2016 with defects liability period running from this

point. The hot water service must be maintained and supplied to the residents through out

the entire project as detailed within the specification.

3.11.1 Main Plant Room (Phase 1)

Install temporary boilers, one to each sub plant room to supply hot water and heating to the

associated blocks on the estate for the duration of the project. (Minimum phase 1&2)

Contractor is to ensure that adequate facilities are available for installing the temporary

boilers i.e. gas, water, electricity, oil in accordance with the requirements laid out in this

specification and all the current standards and regulations

The temporary boilers are to be installed and completely up and running prior to any removal

work. The temporary boilers will be connected to the existing plant rooms and provide the

hot water services to the dwellings until ready for change over to new system.

Locations of the temporary boilers are to be agreed by the client/contract administrator

before installation.

The existing gas fired boiler plant is to be completely removed and replaced with new gas

fired boiler plant. This will include two new floor standing gas fired Potterton NRXi-16 high

efficiency boilers, pumps, a flue system for the boilers, to run from the boilers to

approximately 1m above roof top of the plant room total rise of approximately 1½m, a new

Flue Dilution system shall be installed and the existing combustion ventilation louvres shall

be refurbished, new air/dirt separator, new dosing pot, new gas supply and safety valve, new

GMI system with associated detection and knock off system plus all associated pipework

from and to the entry/exit points of the plant room. The existing control panel, and all

associated field controls, control and power wiring and all redundant conduits will be

renewed by controls specialist and replaced with new in accordance with the requirements

laid out in this specification and all the current standards and regulations.

All builders work in connection along with all necessary scaffolding and access requirements

in connection with the entire plant room removal and replacement are to be included and


controlled by the Contractor in accordance with the requirements laid out in this specification

and all the current standards and regulations.

The existing incoming gas supply and dedicated meter shall be reused from the entry point

in the plant room [with contractor carrying out necessary checks and tests as required by gas

safe to the entire gas system] to the new boilers complete with all necessary isolation and

complete with a new emergency gas safety shut-off system of three detectors and knock off

button in accordance with the requirements laid out in this specification and all the current

standards and regulations and new GMI systems.

The new boilers shall comprise of a new high efficiency boilers and new flue dilution system,

complete with dampers as required by manufacturer in accordance with the requirements

laid out in this specification and all the current standards and regulations.

New heating pumps [one per each boiler] shall be variable speed single pumps, complete

with pressure gauge flexible connection each side also fitted with anti-vibration mountings

and an inlet line size strainer in accordance with the requirements laid out in this

specification and all the current standards and regulations. The existing pumps in the plant

room are less than 2 years old, they should be re-used and it is the contractors’ responsibility

to check them to make sure they meet the requirements of the system.

The existing cold water feed to the heating system needs to be upgraded to 22mm. The new

boiler installation in plant room complete with all necessary valves and fittings in accordance

with the requirements laid out in this specification and all the current standards and

regulations and pressure fill system and expansion vessels.

A new control panel, field controls and all associated control and power wiring along with

necessary containment shall be provided, via controls specialist direct employed by the

contractor in accordance with the requirements laid out in this specification and all the

current standards and regulations.

The contractor shall allow for the provision of a new air/dirt separator and new dosing pot to

be installed within the new plant room installation in accordance with the requirements laid

out in this specification and all the current standards and regulations.

Any flanged items required shall match equipment and shall be complete with all necessary

nuts, bolts washers and gaskets etc. rated to the required pressure/temperature in

accordance with the requirements laid out in this specification and all the current standards

and regulations.

Install complete pre-insulated underground primary heating distribution pipe work system

complete with alarm system to supply all four sub stations, including all civil works, fencing,

signage, lighting, boarding, shoring, access requirements for emergency services,

pedestrian and vulnerable people’s needs in accordance with the requirements laid out in

this specification and all the current standards and regulations.

The existing heating pumps (to be re-used if possible) and associated pipe work, valves,

fittings and controls are to be removed. The existing HWS system is to be retained and

connected to the temporary boilers and used until changeover is possible to the new system

making the existing system redundant in accordance with the requirements laid out in this

specification and all the current standards and regulations.

Supply and install new high instantaneous plate heat exchangers to each sub plant room,

including new heating and hot water circulation pumps, motorized valves, control valves,

safety valves, isolation valves, electrical controls, control panel, lighting, power sockets,

ventilation, temperature and pressure gauges and any associated works in accordance with

the requirements laid out in this specification and all the current standards and regulations.


Once entire system has been installed, the whole system is to be fully chemically cleaned

(not power flushed) re-tested, flushed and insulated throughout and left filled correctly

chemically dosed, primed and ready for operation in accordance with the requirements laid


3.11.2 Phase 2. Secondary heating and hot water distribution circuits.

On completion of phase 1, the existing secondary heating distribution circuit is to be isolated,

drained down, and stripped out to allow room for the new hot water circuit to be installed in

accordance with the requirements laid out in this specification and all the current standards

and regulations.

On completion of the installation of the new hot water circuit, including flushing, chlorination

and testing each dwelling is to be connected to new distribution pipe work for hot water and

the temporary plant must be connected to the new pipe work as well. Potentially the

temporary plant will supply domestic hot water to the existing hot water distribution pipe and

the new distribution pipe until all dwelling on that particular sub plant room are switched to

the new system. The now redundant hot water circuit can be isolated, drained and stripped

out. Making room for the installation of the new heating circuit pipe work in accordance with

the requirements laid out in this specification and all the current standards and regulations.





Note: The existing and proposed route for the new pipe work runs directly under the

balconies outside each dwelling. The estate has recently had new access panels fitted

along these balconies covering the existing pipe work and isolation valves. The

contractor must take all necessary precautions to ensure that the panels are not

damaged and replaced back correctly throughout the duration of the project. The

contractor will be held responsible for any damage caused by the installation of the

new heating and hot water systems and will be required to make good any damage

and or supply and fit like for like at their own cost.

3.11.3 Phase 3. Indwelling heating and hot water installation.

On completion of phase 2 the existing heating and hot water systems within each dwelling

can be isolated, drained down, stripped out inclusive of all radiators, pipe work, valves and

fittings, controls any associated works in accordance with the requirements laid out in this

specification and all the current standards and regulations.

Supply and fit all new radiators, pipe work, valves, controls, electrical and any associated

works. To supply the heating and hot water within each dwelling in accordance with the

requirements laid out in this specification and all the current standards and regulations.

Just outside the flat at high level a new DMS heat meter and new hot water meter (see

schedule) and stop cock either side shall be installed. The meter DMS or equal and

approved in accordance Metering and Billing Regulations 2014.






Heating Design Conditions:

The L.P.H.W. heating system has been designed on the following criteria, when the external

temperature is -3°C db, assuming a boiler flow temperature of 80°C and a return

temperature of 60°C.

Design Temperatures Infiltration Rates

Living Room: 21C 1.5 ACH

Dining Room 21°C 1.5 ACH

Bedroom: 21C 1.0 ACH

Bathroom and WC: 22C 2.0 ACH

Kitchen: 21C 2.0 ACH

Hall/Landing: 21oC 2.0 ACH

Pipe Sizing Criteria

Pipe Size (mm)

Velocity m/s Total Pressure Drop pa/m

15 – 50 0.75 – 1.15 100 - 350

> 50 1.25 – 3.0 100 - 350

Pipe sizing is based on the requirements of CIBSE Guides.

Air change rates are taken from the Domestic Heating Design Guide to Current Practice with

sufficient additional allowance made for ill-fitting windows, chimneys, flues and other

elements affecting heat loss.

When selecting radiator sizes due allowance has been made for the reduction in output due

to the actual mean water temperature/room temperature.

Additionally, the radiator output in each room exceeds the design heat loss by a minimum of

10% to allow for “heat-up”.

Emissions from exposed pipework have not been taken into account when selecting radiator

sizes.

When calculating heat loss the adjoining occupied premises have been assumed to be at an

internal temperature of 10°C.

When assessing the required boiler heating output for the boilers this exceeds by a further

10% the sum of the calculated, required radiator outputs (inclusive of the 10% “heat-up”

allowance).

When pipe sizing the heating circuits no more than 4kW actual output is fed by 15 mm

pipework.

Pipework

The pipework for this system shall be as detailed within section 3.31

Operation of Heating System:


Heating within each flat is to be controlled by a [Honeywell V4043H] two port control valve

with [Honeywell DU144] auto bypass and a wall mounted heating [Honeywell

CMT907A1401] programmable thermostat. The thermostat is provided to shut down the

heating circuit on satisfaction of demand (all to comply with latest revision of Part L of the

Building Regulations), plus all associated radiators are to be fitted with standard lock shield

radiator valves on return and a thermostatic radiator valve on the flow to provide final room

temperature control zoned accordingly wiring of controls shall be via [Honeywell 420022116

001] junction box. Note that the radiator within the room that is fitted with the room

thermostat shall be fitted with a standard manual radiator valve on the flow

Radiators:

All radiators within building shall be as manufactured Quinn (one radiator manufacturer

throughout whole project), complete with Honeywell type [VTL12OE-O15EG] thermostatic

[and manual where necessary] radiator valves on flow and Honeywell range of lock shield

valves on return.

Each radiator is to be provided with a thermostatic radiator valve on the flow connection and

a lockshield radiator valve on the return connection. All valves shall be angle pattern,

chromium plated and pressure rated to at least 4 bar.

Radiators are to be connected top and bottom opposite ends with thermostatic valves on left

hand bottom corner.

Consequently, radiators may be required to be provided with four tappings with unused

connections plugged and provided with manual air vent at the top.

Radiator fixing heights must be sufficient to permit the passage of surface pipework and mini

trunking beneath with adequate clearance below the pipework to the floor and sized to cover

the existing radiator that it is replacing.

Account should also be taken of the ease with which a disabled user can access any integral

controls and the use to which the room/space will be put.

3.12 PROPOSED HOT WATER INSTALLATION DISTRIBUTION IN DWELLINGS

The hot water requirements are designed to provide adequate amounts of hot water to fulfil

all normal operations of each dwelling.

The secondary hot water flow runs from entry point of dwelling to all necessary outlets in

kitchen and bathroom and must be insulated throughout. The hot water return shall be

terminated at the boundary to all flats, and fitted with a Herz CTC valve, to maintain

temperature and circulation.

Just outside the flat at high level a new DMS 749 QPI 1.5 heat meter and stop cock either

side shall be installed. The hot water meter shall be DMS JSC90-NK 4 or equal or approved

in accordance with Metering and Billing Regulations 2014. Contact at DMS for meters is:

Chris Bishop

DMS Ltd.

Tel 01773 534555

Email: [email protected]

Every connection to all water using appliances and sanitary ware shall be provided with an

appropriate means of local isolation (stopcock, ballofix, quarter turn isolating valve).


Baths shall be fitted with a building regulation ADG3 thermostatic mixing valve as Honeywell

[TM300-3/4H TMVZ] approved mixing valve or equal and approved.

The washing machine and dish washer connection [if present] shall require a ball type,

compression ended appliance valve installed with the open end ‘looking down’ and the

pipework additionally clipped to ensure rigidity.

All outlets (hot water) to be fitted with in-line flow restrictors (such as Cottam and Preedy C.P

961 range of restrictors and local service valves) to reduce water consumption, tap outlet

flow to be maximum 8 litres per minute, showers to be 16 litres per minute but not spray

caps, all outlets to have a local service valve, plus each room to have external to the room

isolation valves.

Accessible and removable access points must be provided to service, for all valves

associated with all services

Hot Water Design Conditions

The hot water service requirements are based upon the following criteria assuming hot water

flow requirements of:

Bath 0.3 l/s (18 l/min) Wash Basin 0.15 l/s (8 l/min) Sink 0.2 l/s (12 l/min) Washing machine 0.2 l/s (12 l/min) Shower 0.1 l/s (16 l/min)

The design of water services in accordance with BS 8558:2011 & BS EN 806.

Pipe Sizing Criteria

Pipe sizes are generous to maximise flow and reduce pressure losses due to frictional

resistance and noise:

Pipe Size (mm)

Velocity m/s Total Pressure Drop pa/m *

15 – 50 0.75 – 1.15 100 - 350 > 50 1.25 – 3.0 100 - 350

* Dependent upon available head.

Pipework

The pipework for this system shall be as detailed within section 3.30

Note:

The contractor will be required to administer a programmed for all the of these works

in such a way that minimizes any inconvenience to the occupiers. Hot water services

will be restored to each dwelling before the end of each day and temporary heating

will be provided by the contractor especially for vulnerable residents should the need

arise as detail within the specification.

3.13 EQUIPMENT SELECTION – MECHANICAL

All equipment and materials selected shall be of good quality and comply with the

requirements of the appropriate B.S. specification and shall be rated at pressures and

temperature required for the required temperature hot water.

Where the names of manufacturers are stated together with any detailed specification of

their products, these are given as an indication of the quality and workmanship required.


Listed hereafter are specific items required in the new installation.

The tenderer may include in his tender the cost of alternative manufacturers, provided that

such alternatives are equal in the opinion of the Client’s Representative in all respects with

regard to quality, workmanship, performance, durability, appearance and compatibility with

the design. A full list of all alternatives must be given with submission of tender

including all detailed cost changes.

This is not a fully comprehensive list and any items not indicated and deemed necessary as

forming part of the completed installation the Contractor shall make due allowance for.

3.14 BOILERS

The existing 2 no. gas fired boilers and flue headers shall be removed, disposed from site

and replaced with new gas boilers. Provide and install 2 No. wall mounted heating, gas fired

condensing boilers, located where indicated on the Tender Drawings.

Each boiler will have a minimum rated output: 1100kW and setup to deliver 85/65ºC LTHW

F&R. The boilers will be timed/sequent/optimised controlled by the BMS.

The boilers will be supplied and installed with the isolating valves on flow and return, drain

cocks, non-return valves, pressure gauges, safety relief valve, condensate pipe upvc to floor

gulley, plus inlet & outlet temperature gauges.

The boilers shall be as follows (or equal and approved):

Model: Potterton NRXi-16 high efficiency boiler complete with fluecade kits.

Output: = 928 kW each (82-71 F&R) Flue size = 400mm internal

diameter.

Flow connection: = 139.7mm Return = 139.7mm

Gas: = 2” Condense = 1 1/4”

The Gas Burners are to be Riello RS160/M BLU c/w MBC1200 SE 2” gas valve.

Each boiler shall be provided with the following:

All complete with Gas flue system inclusive of header and riser through roof with weathering

and termination.

Each boiler shall be supplied with intelligent ‘abc’ boiler controls complete with numerical

display providing operating and service parameters. (The boiler(s) shall be suitable for

operation on 240v – 1ph – 50 Hz a.c.)

The Contractor shall make due allowance in his price for the boiler manufacturers to attend

site and carry out commissioning of all boilers and auxiliaries.

The above boilers will be manufactured by Potterton Limited, Wood Lane, Erdington,

Birmingham B24 9QP. The contact is Peter O’Brien, Tel. 07889 752217,

[email protected]

The new system will be connected to a fill and pressurisation unit, with cold feed from the

existing feed tank in the tank room located over the lift motor room.

Each boiler is to be fitted with a DN28 Nabic F542 safety valve set @ 2.7 bar with the

discharge side of valve to be fitted with barrel pipe run to terminate 100 – 150mm from

finished floor level.


Existing combustion ventilation in external wall to be checked via BS: 6644 requirement, the

contractor is to allow for cleaning and repainting of the louvres to match the existing finish.

3.15 PROPOSED HOT WATER SYSTEM

The new hot water system will be an instantaneous Plate Heat Exchanger system by

Ormandy Rycroft or equal or approved. These will be installed complete with a buffer vessel.

The room that sits below the sub plant room is available to extend the existing plant; it is

proposed to install the buffer vessel in the lower room. The contractor is to supply with each

PHE a spare plate that is to sit in the plant room to allow a changeover if required, and allow

minimum disruption of the HWS during maintenance periods.

3.16 BOILER FLUE SYSTEM

Each boiler will be fitted with a 400mm Ø flue single wall flue that will rise to above and go

through the ceiling of the plant room and into the flue dilution system on the roof of the plant

room. See drawing for flue dilution details.

Each boiler shall be fitted with flue damper if required by the manufacturer these shall be

fitted into the rise off of each individual boiler in plant room.

A new flue system shall run with all necessary fittings, tees, connectors, locking bands,

terminations, cleaning doors, maintenance collars, supporting brackets including external

weathering and condensation to drain complete with U trap.

The flue specialist will be A1 Flues, the new flue systems will be manufactured in single skin

manufactured to BS EN1856-1 constructed from AISI 316L stainless steel or equal and to be

approved and be suitable for non-condensing high efficiency boilers.

Contact at A1 Flues is:

Lee Willson

Area Sales Manager

Sales Department

A1 Sheet Metal Flues Ltd.

[email protected]

3.17 BOILER ROOM VENTILATION

3.17.1 Main Plant Room

The existing ventilation louvres in wall of plant room has been checked via calculation using

BS 6644 & is confirmed as being adequately sized, the contractor is to arrange to clean and

paint these to match the existing finish.

3.17.2 Secondary Plant Rooms

These louvres have been checked and can remain as installed. The Contractor is to provide

a cleaning service and repaint of these louvres whilst on site.

3.18 HEATING LTHW PUMPS

3.18.1 Primary Pumps

The primary pumps will be Grundfos pumps (see schedule of equipment).

mailto:[email protected]


The pumps shall complete with volt free contact for remote fault indication on the control

panels BMS, and shall be suitable for the 85°C LTHW.

3.18.2 Heating Pumps

The primary pumps will be Grundfos pumps (see schedule of equipment). The existing

pumps are to be used if they are capable of supplying the system. The CA must be

consulted before they are discarded.

3.18.3 Secondary Heating Pumps (Sub Plant Rooms)

The primary pumps will be Grundfos pumps (see schedule of equipment).

The pumps shall complete with volt free contact for remote fault indication on the control

panels BMS, and shall be suitable for the 85°C LTHW.

3.18.4 Hot Water Circulation Pumps Sub plant Rooms

The hot water circulation pumps will be supplied as part of the Rycroft Brreeze

Instantaneous package.

3.19 PUMP ANTI-VIBRATION MOUNTINGS AND FLEXIBLE CONNECTIONS

All new circulating pumps shall be fitted on wall mounted anti-vibration mountings and

complete with flexible connections.

The flexible connections shall be suitable for the fluid temperature and pressure to which

they are connected. The anti-vibration mounting shall be selected to suit the overall dynamic

weight of the equipment, positioned in conjunction with any support or framework as

necessary to achieve a totally independent assembly for wall mounted pumps.

All as supplied (where possible) by the pump manufacturers

3.20 PRESSURISATION UNIT

The primary heating circuit shall be filled with a purpose made electronic filling device and

expansion vessel, by Mikro fill Systems Ltd [or equal and approved] model type 3200/4..

Electrical requirements 230/1/50 with 3A fuse rating.

Contact details, Mikrofill Systems Ltd: 03452 606020 ([email protected]). See schedule for

details.

3.21 COMBINED LLH AIR AND DIRT SEPARATOR

The Contractor is to provide in the existing secondary return pipe a combined air and dirt

separator [with isolating valves each side] unit a XC200F SpiroCross Hydraulic Deaerator &

Dirt Separator DN 200 Flanged ends manufactured by Spirotech UK Limited, PO Box 818,

Altrincham, Cheshire WA15 5GZ (Tel: 020 8451 3344 Fax: 020 8451 3366).

The installation shall allow for the system to be cleaned and emptied of dirt until deposits

within the system have been removed and be complete with a pressure gauge and an

isolating valve either side. The unit shall operate in 82 – 71°C heating water at a flow rate up

to 40 kg/s, giving a velocity of about less than 1 m/s and is to be located across the flow and

return.

3.22 DOSING EQUIPMENT

Once the LTHW heating (primary and secondary) systems have been thoroughly

cleaned/flushed and accepted by the Clients Representative, the systems shall then be


treated with a necessary inhibitor and biocide, by water treatment specialist Aldous and

Stamp or Good water or equal and approved.

A new 16 litre dosing pot to be installed the first across the primary flow and return

connections, as indicated on the Tender Drawings. The water treatment shall be a closed

system corrosion inhibitor and biocide which shall be a non-polluting product to provide

corrosion inhibition and deposit control suitable for a closed recalculating water system. The

treatment shall be of a low toxicity to ensure ease of handling and to minimize system water

disposal problems and shall be as required by the boiler and plate heater manufacturers.

Chemicals shall be provided in sufficient quantities for the initial fill and twelve months

maintenance.

The dosing pots shall comprise a heavyweight mild steel tube with welded seams, 15mm

BSP connections with globe valves, an air release cock with fill tundish and a sample/drain

cock.

The dosing pots shall be installed across the flow and return connections on both systems

and shall be suitable for the working pressure of maximum 10 Bar.

Dosing Pot Size = 16 litre

The dosing pots shall be arranged such that it may be used not only for the injection of

chemicals into the system, but also as a sample pot for testing the quality of the water. The

dosing pot shall be manufactured by Aldous and Stamp or Arrow Valves or equal and

approved.

3.23 PRESSURE AND TEMPERATURE GAUGES

Pressure gauges syphon and plug cocks along with temperature gauges and pockets, shall

be as detailed within Section 2 of the specification “Standards of Materials and Workmanship

– Mechanical”.

3.24 THERMOMETERS

Thermometers and pockets, shall be as detailed within Section 2 of the specification

“Standards of Materials and Workmanship – Mechanical”.

3.25 STRAINERS

Pipeline size strainers shall be installed as indicated on the Tender drawings and shall be as

detailed within section 2 of the specification “Standards of Materials and Workmanship –

Mechanical”. with a minimum of one fitted to the entry port of all pumps.

3.26 VALVES

Valves shall be fitted where indicated on the Tender Drawings and in accordance with the

standard specification and shall be Herz or Crane or equal and approved.

LTHW rated to temperature of at least 95ºC and rated pressure of 16 bar

LTHW valves shall be generally as detailed within Section 2 of the specification “Standards

of Materials and Workmanship – Mechanical”.

Isolation (IV) Up to 2”Ø either Herz K-KV or Crane D171A. Over 2”Ø either Herz BF-FLL or Crane F624. Regulation (DRV) Up to 2”Ø either Herz 4217 or Crane D920.


Over 2”Ø either Herz 4218 or Crane DM920. Commissioning (CS) Up to 2”Ø either Herz 4217CS or Crane DM931. Over 2”Ø either Herz 4218CS or Crane DM940. See Schedules for specific control valve requirements. Drain Cock (DOC) Shall be Hattersley 371 Lock shield pattern. Test point (TP) Shall be test plugs Mechseal M2. Air vents (AAV) Shall be Charles Winn or Oventrop 108.32. Safety valve (SV) Shall be to BS853 Nabic Fig. 542 type, see boiler details. 3 way vent cock

(3WC) Shall be Nabic Fig. 175.

Lockshield Valve Thermostatic Radiator Valves

(LSV) (TRV)

Shall be to BS 1010 stop cock lockshield arrangement. Honeywell

All low points of the heating, hot and cold water systems shall be provided with drain valves.

All high points shall be provided with automatic air release valves.

3.27 COLD WATER (PLANTROOM)

The cold water supply for the plant room will serve from the existing incoming main; this will

require increasing the pipe size from 15mm to 22mm.

The run shall be complete with all necessary stop cocks, pipe and fittings, insulation with

vapour seal and chlorinated after testing and before use.

3.28 COLD WATER IN SUB PLANT ROOMS

The cold water supply for the hot water system is supplied by CWST’s in the roof space,

these tanks are to be replaced and the feed to the sub plant rooms need to be replaced. A

new cooling tank for the hot water open vent is to be installed in the roof space this is to

have all valves and pipe work associated with a cooling tank.



3.29 COLD WATER SUPPLY TO DWELLINGS

The cold water mains and CWDS to the dwellings is to remain in place, the contractor should

allow a provisional sum for repair and changing of inoperable valves that are required to

complete the job.



3.30 COLD WATER SUPPLY GENERALLY

After all work has been completed on the cold water system shall be sterilized / chlorinated

in accordance with BS 6700:1987 Section 13.9.


Before chlorination, all necessary service pipes, tanks and cisterns shall be flushed out to

remove dirty water, debris etc., refilled with clean water and flushed again.

No water shall be used for domestic purposes during this flushing operation, nor until

chlorination has been completed.

3.31 GAS VALVE

Plant Room Gas

The gas supply shall be purged and disconnected at low level in plant room from the existing

solenoid valve and temporarily blanked accordingly.

Then the two boilers shall be reconnected to the existing solenoid valve at high level with

new pipe work gas cocks and reducers as required.

A gas certification shall be provided when each boiler is installed/connected to existing gas

system. The entire system shall be re-certificated twelve months later just prior to end of

defects.

The new gas solenoid valve shall be a new emergency Black Teknigas power seat electro

hydraulic gas valve 9equal or approved) which shall be installed to protect the new boilers

within the plant room and shall consist of a Power seat Series gas safety shut off valve sized

at that is fast opening type shall be installed, complete with three thermal links, CO and gas

detection and knock off button.

See schedule for details of all gas safety equipment. Contact for Blacks quote is:

[email protected]

Watts Industries UK Ltd

Colmworth Business Park

Cambridgeshire | PE19 8YX

3.32 PIPEWORK MATERIAL

3.32.1 General Pipework Above Ground

Pipework and fittings shall be as detailed within Section 2 of the specification “Standards of

Materials and Workmanship – Mechanical”.

Heating Systems, all sizes black heavyweight steel tube welded. Cold water mains, tank

overflow and warning pipe, all sizes copper tube to match existing with pre-soldered fittings;

the condensate drain shall be UPVC.

3.32.2 Underground Heating Mains And Trench

Careful consideration shall be made by installer during installation regarding anchoring and

expansion throughout the entire pipework system.

The new circuits shall be fitted with all necessary valves including drain valves.

The routes of the new heating circuits are indicatively shown on drawings and may be

affected by structural/architectural works and hence due allowance should be made for this.

The contractor shall allow for a complete underground scan of all phased area. All

underground heating pipework shall be as detailed in Southwark specification “for pre-

insulated steel underground, district heating distribution pipeline”, see attached Appendix A

of this specification.

mailto:[email protected]


Appropriate methods of pipe jointing as detailed in the Southwark Specification, “for pre-

insulated steel underground district heating distribution pipelines”, see attached Appendix A,

noting the pressures involved, must be adopted.

The heating system shall be pressure tested, flushed and inhibitor installed to the correct

levels for the entire system before final insulation and labeling of installation is commenced.

The new heating system shall be provided with all necessary valves etc. to enable the

installation is to be provided with an inhibitor to match existing system, but prior to its

installation the system shall be cleaned and flushed with suitable chemicals. Full compliance

with the requirements in Southwark specification “for pre-insulated steel underground district

heating distribution pipelines” and the Standards of Materials and Workmanship sections, is

required.

The new underground mains within new trenches (trenches provided by contractor who

needs to ensure that they are correctly sized, have access points, in correct location and

routes) and existing trenches shall be run in purpose made pre-insulated steel underground

pipework system (see Appendix A).

The underground mains will be deemed to include the rise out of the ground in the plant

room and/or branch risers and into the manholes and dwellings to blocks as indicated on

drawings. Valves in block manholes and dwellings shall be complete with drain cocks and

air vents where necessary.

Note pipework both flow and return into and out of the manhole shall be complete with

puddle flanges.

Note: all builders’ works, trenching, making good to be included in costs by mechanical

contractor.

Note also that the underground pipe systems shall be complete with leak detection systems

and alarm that is complete with visual on screen leak location indication, alarm,

controls and visual indication screen shall be located within local plant rooms (as

indicated on drawings) in accessible position to operate and view along with

associated alarm indication drawing.

The services being replaced are the secondary heating flow and return and the hot water

primary heating flow and return.

The heating circuit arrangements as indicated on the tender drawing.

The contractor shall carefully dig within the vicinity of the existing pipework distribution and

services using hand digging where near existing services or trees. Ground penetrating radar

shall be used to locate existing buried services prior to digging.

The new underground pipework distribution shall generally either run adjacent to existing in

existing trench or run in new trench adjacent to the existing services with crossovers used to

breach existing pipework as necessary.

All new underground pipework trenches shall generally be run at the following minimum

depths (to top of insulated pipe):

LTHW secondary heating mains 0.5m.

Deeper trenches will be necessary in certain areas to ensure a minimum of 500mm above all

new buried services. 150mm clearance shall be used around al pipes.

A typical LTHW trench will be as follows:


Note: New pipe within existing open trenches the pipe shall be supported by purpose made

Unistrut support [from floor/wall] system provided by pipe manufacturer/supplier.

The contractor shall submit working CAD drawings in detail and sections showing installation

details prior to works commencing, and detailed CAD plans showing the exact location of all

new pipework dimensioned from buildings.

The exact trench depth shall depend upon pipe invert levels and pipework to be run

horizontally without undue changes in level. There shall be no buried drops or risers.

The contractor shall be responsible for final pipework layout design and shall include for all

expansion provisions including take-off sets. Pipework expansion shall be taken up by loops

and bends where the expansion length shall be accompanied by movement tolerances

within the pipework bends. Foam pads shall be used to absorb the expansion movement in

accordance with the manufacturer’s recommendations.

An additional 500mm width shall be used in all changes of direction to facilitate pipework

movement.

The pipework distribution shall be kept >2m from the building structures where possible. If

this is not possible the take off section shall ‘dog-leg’ back 1m to allow for movement offset

i.e.


All new underground pipework shall be spaced 150mm above

the trench base level and once tested shall be filled and

compacted with sand to a minimum surround of 400mm.

Compaction to be carried out using a flat-bed vibrator with a

maximum ground pressure of 100 kPa.

A warning tape shall be placed at least 200mm above the

pipework. Backfilling shall comprise a minimum cover of

500mm above the sand fill.

During installation all open ends shall be blanked/capped securely at all times to prevent

direct ingress.

All bends, tees and fittings to be factory made pre-insulated components.

3.33 UNDERGROUND PIPEWORK LEAK DETECTION SYSTEM

There shall be reference points in each section of estate served.

The alarm system shall be in accordance with the detail contained with Southwark Councils

General Specification for the Installation of Steel Underground pipework see Appendix.

3.34 LEAK FAULT LOCATOR PANEL (FULL MONITORING WITH READOUT)

The fault locator panel shall be complete with visual on screen leak location indication,

alarm, controls and visual indication screen shall be located within local plant rooms as

shown on drawings in an accessible position to operate and view along with associated

alarm indication drawing. The panel will be located in the main plant room.

The fault locator panel shall be capable of monitoring a minimum of 4 circuits and shall

continuously send out encoded pulse signals on the tinned copper wires within the pre-

insulated pipework.

If the signals meet any abnormalities ie: short circuits, moisture or breakages, it will reflect

back at the fault locator panel. In the event of an abnormality being located the unit will

indicate the distance in metres and the circuit number on which the fault has been located.

A laminated alarm layout drawing shall be located adjacent to the fault locator panel, this

must identify each circuit and will assist in locating the fault on the underground mains

pipework.

The fault locator panel shall have volt free contacts for connection to a BEMS to allow the

status of each of the alarm circuits to be monitored remotely.


3.35 WORK WITHIN TRENCHES

Risk assessment and method statement to be produced relating works within existing

trenches and to all new trenches excavation work (the requirement or non-requirement of the

shorting up of excavations should be clearly addressed within the rise assessment).

New trenches shall be dug 1m wide minimum to facilitate safe access for the new pipework

installation.

All existing earth and spoil to be removed from site unless spoil heaps can be used to

increase site safety by segregating the area away from the general public.

All trenched areas where work is undertaken including areas within the trench, shall

incorporate 2 meter high heras fencing and timber side shoring to both sides to minimize

the risk of collapse. Access shall be facilitated by properly tied ladders protruding at least

1m above ground level or by purpose made timber steps subject to the contractors Risk

Assessment. All other areas shall have a soil slope (angle of repose) of 45º to minimise

potential collapse.

All trenches to have steel barriers erected either side to create proper segregation of the

working and public areas. Suitable and sufficient signage and lighting shall be used. Where

the trench passes a common walkway a 1m wide bridge shall be erected complete with side

handrails and toe boards to provide safe access to al personnel including the public.

Where handrails are used these shall be 910mm above ground level and incorporate an

intermediate handrail at 470mm and toe boards where there is danger of falling objects.

All trenches shall be treated as potential confined spaces and daily gas testing shall be

undertaken prior to work commencing.

Trenches shall be inspected on a daily basis and a record shall be kept sign the form

contained within the Appendices.

All workmen shall wear adequate and sufficient PPE including hard hats, gloves, toe

protection and high visibility tabards.

All lowering of pipework shall be undertaken by using mechanical pulleys hoist to avoid

unnecessary manual handling.

3.36 RADIATORS

Radiators shall be of the size and type and the minimum heating surfaces indicated in the

Schedule and/or on the drawings.


The Contractor shall check the dimensions of all radiators prior to ordering to ensure that the

sizes specified can be accommodated in the space available and that none shall project

above window sills.

Radiators beneath windows shall be fixed, wherever possible, with the space between

radiator top and window sill at least 50 mm.

All radiators shall be fixed a minimum above floor of 100mm where pipes are under floors, or

150 mm where pipes are above floors.

On all breeze or lightweight partition walls, radiators shall be supported on the special

brackets suitable for purpose.

All column radiators above fifteen sections in length shall be provided with three bottom

brackets and two top stays and radiators above twenty-five sections with four brackets and

three stays, or as recommended by the manufacturer.

Connections shall be properly set to suit the width and length of radiator to be served.

All steel panel type radiators shall be supplied complete with all necessary brackets, air

cocks, plugs and support brackets and shall be delivered to site packaged with tough

polythene, translucent covering with tappings protected inside the covering by plastic plugs

and cardboard corner covers.

The Contractor shall ensure the covering is retained, after the radiators have been fixed and

only removed for painting and testing and balancing, at final completion.

Steel panel radiators shall be to BS EN 442 including all amendments and supplied in stove

enamel white primer ready for final painting. Should any rust appear, after the radiators have

been fixed, the Contractor shall clean the rusty areas thoroughly and then apply one priming

coat, prior to the finishing coat being applied.

Except where otherwise specified, each radiator shall be provided with two union valves, one

with lockshield and one with handwheel or thermostatic type as specified later, and 3mm

loose key air-cock or airlet plug. Connections shall be made so that valve spindles are truly

vertical; valves fixed out of vertical alignment will not be accepted.

For panel radiators fixed at high level or on ceilings, the control valves shall be fixed in the

positions indicated on the drawings or specified in the general description of the work and

aircocks shall be omitted, the pipe connections being so arranged that air is eliminated at

suitable high points in the piping.

The Contractor shall allow for taking down, removing and refixing each radiator twice only

after installation to allow for painting, plastering or tiling, etc.

The Contractor shall be responsible for ensuring that all radiators are fixed firmly and

securely in position, to the satisfaction of the Engineer.

3.37 CONTROLS

The contractor shall employ a specialist controls sub-contractor to supply, install, test and

commission, a new MCC control panel with a Trend BMS system. The controller unit shall

have an interface facility for connection to the offsite Head End unit for monitoring, located

on the at the Leather market JMB office, 26 Leathermarket Street SE1 3HN .The existing

system is Trend IQ controller installed with LAN Modem & SIM, including the following Trend

IQVIEW4/24 display, Trend NBOX/TMNG/EUR/230 modem, Trend IQ3 XCITE/96/LAN/230

controller & Xcite modules as required all installed by

The control system will include an operator’s keypad fitted on the control panel facia, to offer

the facility to interrogate the control system. The panel shall have a panel mounted GMS unit


suitable for the Vodaphone network for interfacing with the remote Head End unit. The SIM

card will be Leather market JMB.

The new MCC control panel will be powered with a new feed from the local electrical

distribution panel. The panel shall be purpose made from press steel panel and complete

with door interlock isolator control circuit MCB, panel live lamp. The unit shall be complete

with all starters, MCBs, Overloads, Run Lamps, Trip Lamps, H/O/A switches, rotary switches

and identification using traffolyte labels.

Prior to the panel fabrication and the installation works the contractor shall submit the

Leather Market Project Engineer/ DMP the power design, controls design, wiring diagrams,

panel facia drawing and controls description for approval.

The new control panel shall be mounted in the main boiler room and sub plant rooms on wall

as indicated on the Tender drawings to provide power, control and alarms monitoring for the

following items of plant:-

• The two heating boilers.

• A three-port secondary control valves.

• Two primary heating pumps and invertors.

• Two heating run and standby pumps and inverters.

• Two shunt pumps and invertors

• Boiler circuit Electronic filling and pressurisation unit.

• Automatic sequence of boilers.

• Gas Solenoid valve, sensors, and thermal sensors & knock off button.

• The entire system frost protection and night setback facilities

• Link to fire alarm.

• Link to Head end unit.

• All field sensors controls and primary and secondary side sensors.

• Ability to provide out of hours operation.

• Adequate sensor requirements for this phase & future phase 2 works [allow four for

phase 2 Sub plant rooms].

• Hot water circulating pumps (Sub plant rooms)

• Secondary Heating pumps (Sub plant rooms)

• All three port secondary control valves (Sub plant rooms)

• Flue dilution fan interlock

The control panel shall be two compartments (one side for controls, the other for power for

plant). It shall be (wall mounted if possible or) floor mounted (on 100mm reinforced concrete

base with 100mm clearance all around) sheet steel enclosure housing:

• Door interlocks mains on load isolator.

• Fire alarm shut down circuit.

• Control circuit MCB.


• Control circuit line lamp.

• 400 & 230 power requirements.

• Control circuit transformers.

• All necessary motor starters complete with MCBs, thermal overloads, run/fault

lamps, hand/off/auto switching for all necessary equipment.

• BMS outstation.

• Interface/control relays.

• Cabling facilities.

• All necessary equipment for recording metering rates, water, and heat.

• Electrical sub meter.

• Three phase fault detection and alarm

The BMS system is to be able to display and record as a minimum the following parameters:

• Display and record each boiler heating flow temperature

• Display and record the main heating flow & Return temperatures

• Display and record the external ambient air temperature

• Display status the of each of the boilers

• Display status of each of the primary heating pumps

• Display status of each of the secondary pumps

• Display status of the heating system fill and pressurisation unit

• Display and record the gas meter, electrical meter & water meter (if not installed,

leave space for future)

• Display and record the status of the main gas automatic safety shut off valve.

Power isolators for plant fed from the panel will be provided adjacent to each item of plant for

local isolation for maintenance.

The HVAC systems are to be controlled by a building energy management system (BEMS).

The new installation and controls wiring is to comply with all relevant statutory authorities

and in accordance with the requirements of CIBSE Guide H: Building Control systems.

3.37.1 General

Controls scope of works, the contractor is to allow for the following:

• Removal of the existing controls installation, after investigation to confirm the

operation of the existing controls scheme.

• The specialist controls company shall provide working drawings, issued for comment

prior to construction of the panel and record drawings, plus operation and

maintenance manuals and provide Client demonstration of entire system, upon

completion of the works.

• Offloading of the panel and positioning in the plant room shall be done by the

specialist controls company.


Via the controls specialist supply, deliver and install the entire controls system inclusive of all

power and control wiring, commissioning, demonstration and handover

NOTE: All meter wiring from metering equipment needs to be picked up and seen on front

end display unit. The following point schedule shall be allowed for as a minimum to

requirements.

Outside the panel the following loose controls shall be provided and installed by controls

specialist:

• All necessary primary and secondary side immersion temperature and pressure

sensors plus outside thermostat.

• Pressure differential switch across all pumps and sets of pumps.

• Allow for future 3-port secondary circuit control valves with spring returns.

They shall include for design, manufacture, test and delivery to site of control panels, control

items and on site commissioning, and Operating & Maintenance/Building User Manual

details.

Also included schematic wiring diagram, set issued for approval, prior to commencement of

construction, and as manufactured drawing on completion.

3.37.2 Proposed control

The proposed controls system shall operate in an automatic manner as follows:

Heating Boilers

The heating plant is to be brought into operation under optimum start control, upon operation

the boiler shall operate to maintain the primary flow temperature of 82ºC to the plate heat

exchanger with a return temperature of 71°C.

Primary side boilers are to be schedule to outside air temperature with all boilers on at –3ºC

with first boiler modulating down until off at 4ºC followed by second boiler full on at 4ºC and

modulating down until off at 11ºC outside, whilst final boiler on at 11ºC with modulating down

until off at 18ºC, All boilers to be sequence controlled

Generally the operation of the plant shall be automatic.

Boiler fault status conditions will be monitored which will initiate alarms on the controller

should a fault condition be detected.

The boilers will be interlocked with the following safety features and will not operate if the

interlocks are not proven via the controls:-

• Boiler Room Gas Safety Circuit

• Pressurisation Unit alarm

• The flue dilution fan

Low Temperature Protection

The system is to include feature that takes information from the external air sensor to switch

‘ON’ all heating pumps and boiler circulation pumps when the external air temperature is less

than 2ºC.

The system will turn the pumps ‘OFF’ when the external air temperature rises to 3ºC.

External High Limit


The system will take information from the external air sensor to switch ‘OFF’ heating when

the external air temperature exceeds 16ºC.

When the external temperature drops below 15ºC the heating zones will be switched ‘ON’ to

resume normal operation.

Boiler Sequence Control

The multi-boiler installation boiler load must be sequence controlled through a sensor in the

return water pipe and through the load sequencing feature (see previous). The boilers are to

be duty cycled through the feature on a weekly basis.


Weather Compensated Systems

The overall compensation control should be set to satisfy the north facing areas of the

building.

Boiler Room Gas Safety System

A new emergency gas shut-off valve will be fitted on the gas supply to the new boilers and

shall work in conjunction with new electro thermo links and emergency stop button.

The emergency gas shut-off will be operated from the control panel and interlocked with the

following:

Plant Room Emergency Stop Button

Two Boiler Electro Thermal Links

Two Natural Gas Detectors

CO2 Detector

If any of these interlocks are broken the gas valve will close and an alarm will initiate on the

control panel.

Fill and Pressurisation Unit

The new Fill and Pressurisation unit shall be power fed from the control Panel. The

Pressurisation’s unit’s Common Fault Alarm shall be interfaced with the panel for remote

alarm indication. The unit will also be interlocked with the boilers to ensure that the boilers

cannot operate for both high and low system pressure alarms.

LTHW Primary Heating Pumps (Main Plant Room)

The LTHW primary heating pumps will operate on/off under the dictates of the attached

boiler they will also modulate in tandem with the attached boiler. The pumps common Fault

Alarm shall be interfaced with the panels’ facia for remote alarm indication.

LTHW Heating Pumps (Main Plant Room)

The LTHW heating pumps will operate on/off under the dictates of the supply circuit return

water sensors from the four satellite plant rooms. The pumps common Fault Alarm shall be

interfaced with the panel’s facia for remote alarm indication.

LTHW Heating (Shunt) Pumps (Main Plant Room)

The boilers are non-condensing high efficiency floor standing boilers, there is a requirement

for a shunt pump to be fitted between the primary flow and return of each boiler for backend

protection.

LTHW Secondary Heating Pumps (Sub Plant Rooms)

The LTHW heating pumps will operate on/off under the dictates of the supply circuit return

water sensors from the dwellings heating circuit. The pumps common Fault Alarm shall be

interfaced with the panel’s facia for remote alarm indication.

Hot Water Supply Controls (Constant Temperature Circuit Sub Plant Rooms)

The hot water service is provided by stored high recovery non storage calorifiers and buffer

vessels. The secondary hot water return will be no greater than 5°C less than the flow

temperature.


Hot Water Circulating Pumps (Sub Plant Rooms)

The Hot Water Circulation pumps will operate constantly. The pumps common Fault Alarm

shall be interfaced with the panel’s facia for remote alarm indication

Variable Temperature Circuit Control (indwelling)

Radiators within existing flats will be complete with new thermostatic radiator valves. The

heating is supplied via the four satellite plant rooms.

Containment

The new power and controls wiring from all the control panel shall be routed in new surface

mounted galvanised trunking and galvanised conduit as later within this clause of the

specification.

3.37.3 Controls Panels – General Standards

Wiring and Termination – When screened cable is required the screen shall only be earthed

at the controller end, not at the sensor. If the controller is mounted in a panel the screen

must continue through the panel direct to the controller.

Where M.I.C.C. is used the outer metal sheath can be earth at the panel gland the wiring

inside the panel must be continued in screened cable with the screen earthed at the

controller end only. The junction between the M.I.C.C. cable and the screened cable inside

the panel should be made as close to the M.I.C.C. gland as possible, the screen of the cable

inside the panel must not be earthed at that junction, but should shroud the conductors as

close to the junction as possible.

Control and power wiring shall be kept separate as far as practically possible. All internal

wiring shall be securely fixed to the enclosures and shall not impede the opening and closing

of doors or removal of components. Where possible ‘crimp’ type connections shall be used.

Control wiring shall be run in plastic trunking where possible. The cable shall not occupy

more than 50% of the trunking volume.

Control wiring shall be neatly arranged and cleated. Cleats are to be fixed to the switchboard

structure at sufficient intervals to avoid cable sag. Adequate cable loops must be allowed to

accessories on doors to avoid cable stretch.

Bunching of cables into large looms shall not be accepted. The maximum number of control

cables in any one group shall not exceed 25 conductors. Conductors for heavy loads shall

be routed to ensure adequate cooling and shall be separated from control wiring. All

unfused cables between bus bars, isolators or fuses shall be routed separately as individual

looms.

Extra low voltage cables shall be ribbon cable rated at 300V AC.

Function Alphanumeric Colour

Protective conductors Green and yellow

Functional earthing conductor Cream

a.c. power circuit (1)

Phase of single-phase circuit L Brown

Neutral of single or three-phase circuit N Blue

Phase 1 of three-phase a.c. circuit L1 Brown

Phase 2 of three-phase a.c. circuit L2 Black

Phase 3 of three-phase a.c. circuit L3 Grey


Two-wire unearthed d.c. power circuit

Positive of two-wire circuit L+ Brown

Negative of two-wire circuit L- Grey

Two-wire earthed d.c. power circuit

Positive (of negative earthed) circuit L+ Brown

Negative (of negative earthed) circuit (2)

M Blue

Positive (of positive earthed) circuit (2)

M Blue

Negative (of positive earthed) circuit L- Grey

Three-wired d.c. power circuit

Outer positive of two-wire circuit derived from three-wire circuit

L+ Brown

Outer negative of two-wire circuit derived from three-wire circuit

L- Grey

Positive of three-wire circuit L+ Brown

Mid-wire of three-wire circuit (2) (3)

M Blue

Negative of three-wire circuit L- Grey

Control circuits, ELV and other applications

Phase conductor L Brown, Black, Red, Orange, Yellow, Violet, Grey, White, Pink or Turquoise

Neutral or mid-wire (4)

N or M Blue

(1) Power circuits include lighting circuits.

(2) M identified either the mid-wire of a three-wire d.c. circuit, or the earthed conductor of a two-wire earthed d.c. circuit.

(3) Only the middle wire of three-wire circuits may be earthed.

(4) An earthed PELV conductor is blue.

Mains cables shall have 600V grade copper conductors, PVC insulated, colour coded as

follows:

1mm2 flexible will be the minimum permissible cable size for mains control circuits.

0.5mm2 flexible shall be the minimum permissible cable size for low current control circuits of

24V only or ribbon cable can be used rated as above.

All internal wiring shall be permanently identified by means of numbered ferrules. These

numbers shall be shown on the schematic diagrams where these are used for point-to-point

wiring.

Co-axial or twisted pair cable shall be specified on wiring diagrams. Screens shall be

earthed as detailed elsewhere.

Terminals shall be of the cadmium plated stud type of a minimum of M5, for accommodating

claw or clamp type washers with suitable cable lugs. Terminals shall be permanently

labelled with circuit references using cable and core numbering procedures approved by the

engineer, and an insulating barrier shall be provided between connections. A maximum of

two connections only shall be made per terminal.

Main cable terminations shall be of the ‘two stud’ type for accommodating crimped cable

lugs. All terminations shall have clearance holes. Cable lugs, fully threaded bolts, plain and

shake proof washers and nuts shall be provided to sit the cable. Cable tails shall be

supported within the equipment at internals not exceeding 450mm. Supports shall be non-

metallic and be attached by mechanical means.


Isolators – Isolators and switch fuses shall conform to BS 5419.

Panels shall be provided with main incoming unfused isolators (except where notified

otherwise) with sufficient auxiliary contacts to enable all live connections entering the panel

to be isolated. Where necessary shrouded isolating relays shall be used together with

isolating link type terminals. Control and interlock circuits shall preferably be powered at the

control panel with local plant isolation via auxiliary contacts of the plant isolators.

All isolators shall be door interlocked on opening sections of cubicles and shall have the

facility for locking in the ‘OFF’ positions, except where internal isolators are specified for

control sections.

For 3-phase 34-wire supplies a neutral link of the same rating as the main conductor shall be

located adjacent to the incoming cable connections. For single-phase supplies the neutral

link shall have a rating equal to that of the line conductor. An efficient earth terminal suitably

labelled shall also be located adjacent to the incoming cable terminations.

All isolators shall be rated for fault current make. Main panel and known resistive load

isolators shall be rated for installed full load current break. Starter isolators shall be rated for

motor start current break.

All connections which are alive with the isolator in the open position shall be fully shrouded

by an insulated cover and identified by a 400V or 230V danger label as appropriate.

Fuses – Power fuses shall be provided for each starter and contactor and these shall comply

with BS 88.

A detailed fuse chart shall be provided and fitted within each panel.

A spare set of fuses containing 10% of the total number of each size of fuse used with a

minimum of 2 for each size, shall be fixed inside the panel with suitable clips adjacent to the

fuse chart.

Starters – Starters for fan and centrifugal pump motors of up to and including 7.5kW shall be

direct on line, above 7.5kW and up to and including 55kW they shall be open transition

automatic star-delta, above 55kW they shall be auto-transformer.

Overloads shall be hand reset, and shall have at least single pole changeover contacts.

Direct on line starters shall comply with BS 4941 Part 1 and shall be rated for intermittent

duty class 0.4.

Automatic star-delta starters shall comply with BS 4941 Part 2 and be rated for intermittent

duty class 0.4. They shall have changeover timers adjustable from one to 30 seconds

(subject to fan or pump characteristics). If the overload relays are connected for phase

current, their scales shall be marked to show whether they are indicating phase current or

lien current.

Electrical and mechanical interlocks shall prevent both star and delta contacts being closed

at the same time.

All starters and contactors shall have auxiliary contacts suitable for remote monitoring of run

indication. All starters/pair of starters and contactors shall be suitable for remote starting and

stopping of plant via a Building Management System (BMS).

Contactors – All contactors shall comply with BS 5424. Unless otherwise specified

contactors shall be of the same manufacture as the starters and be fully enclosed.

Relays – Relays shall be of the plug in changeover type.


Labels – Labels shall be supplied for all instruments and components mounted on the front

of the control panel. Where a group of indication lights and control switches are associated

with one item of plant, a common label shall be used which should describe the components

of the group.

Within the panel adequate labelling shall be provided for all fuses, relays, starters and

control equipment. Such labelling shall correspond in detail with the panel wiring diagram.

Warning labels shall be provided giving notice of any live low voltage circuits existing when

doors are open or when cover plates are removed. Suitable labels shall be fitted identifying

circuits requiring isolation by link type terminals.

Labels shall be engraved on traffolyte or similar laminate; but as an alternative for internal

labels. Plastic trunking lids may be engraved, in which case the trunking lids must be

identified with respect to location.

Labels shall normally have black lettering on a white background, but safety labels shall be

to BS 5378.

All labels shall be fixed either with mushroom head screws with a chromium plate finish, or

plastic rivets the same colour as the label background. Adhesives shall not be used on

panel fascia other than of maintenance references (see clause 2.27).

Ammeters – All ammeters shall be to BS 89 and shall be provided to replace existing only.

The current passed through an ammeter should to exceed 20 amps inductive or resistive.

Above this rating current transformers must be used. Blade terminals are preferred to

accept insulated plug-on connectors or recessed screwed connections to prevent inadvertent

contact. Ammeters for inductive loads such as motors shall have an extended compressed

scale greater than the value of the starting current.

Ammeters must be selected so that the measured value falls within 20-80% of full scale. No

circuit wiring from the L2 or L3 phases will be permitted on the panel door.

Indicator lamps – Unless otherwise specified indicator lamps shall be of the low voltage LED

cluster type.

RED: Essential equipment stopped by action of a protection device.

YELLOW: Temperature, pressure, humidity etc. Outside normal working limits.

GREEN: Machine started/running in normal condition.

WHITE: Panel live/other non-defined uses.

Switches – All switches shall be rotary type and unless otherwise specified shall be break

before make.

In general, switches shall not be capable of continuous rotation; but this may be overridden

for functions such as sequence selection or, in the case of ammeters, phase selection.

Where ‘MANUAL/OFF/AUTO’ switches are provided, the ‘MANUAL’ position shall override

all interlocks except those relating to plant or life safety.

Where interlocks from fireman’s switches or fire relays are provided, these interlocks shall

override the ‘MANUAL’ and ‘AUTO’ positions of ‘MANUAL/OFF/AUTO’ switches.

Instrumentation and Controls – A separate panel section shall be provided for

instrumentation and controls.


All panel fascia items, and adjustable and/or indicating controllers whether fascia or

internally mounted, shall wherever possible, be mounted at a height between 1000mm and

1750mm from finished floor level.

Drawings – Two copies of the panel layout and wiring diagrams shall be submitted for

approval by the Clients Representative.

The panel layout drawings shall be adequately dimensioned, and shall show the

arrangement of all components mounted on the face of the panel.

The wiring diagrams shall show the electrical ratings and full load currents of all motors and

other equipment supplied from the panel, the ranges of all starter overloads, and all fuse

ratings. All wiring and terminals shall be numbered. References and terminal numbers of all

external equipment connected to the panel shall be shown although it is accepted that this

information may not be available at the time of approval.

When the drawings have been approved, the manufacturer shall issue two copies of all

approval drawings.

When the panel doors/interiors have been built and delivered to site, two copies of the as

manufactured wiring diagrams shall be supplied in a rigid document pocket permanently

fixed behind a non interlocked panel door, e.g.: control section.

Works inspection and testing of all panels shall be carried out testing on site in the presence

of the Clients Representative.

The paintwork shall be examined for any scratches or blemishes.

The wiring shall be checked for loose connections, and compliance with the wiring diagrams.

The insulation resistance in each case shall not be less than 20 megohms.

Phase to phase

Phase to neutral

Phase to earth

Neutral to earth

A test certificate for each panel shall be issued by the manufacturer.

The wire all items of power fed from the following control panel as detailed and to the

standards detailed in this specification.

The controls works, supply, commission, testing and install shall be carried out by a controls

specialist either:

Magpie BMS Services Ltd, SBC House, Restmor Way, Wallington, Surrey SM6 7AH. Tel:

020 8642 0863 (contact Russell Dodd)

Or equal and approved.

3.38 ELECTRICAL REQUIREMENTS FOR MECHANICAL SERVICES

The Contractor will be required to completely strip out the existing boiler room switchgear

control panel wiring conduit, luminaires and power outlets retaining the incoming supply for

reuse following a test to confirm that it is sound.


Within the boiler room the contractor will completely replace the existing switchgear including

distribution board, control panel lighting, power and control wiring including all containment,

wiring and accessories. The provision of control panel and wiring will be carried out by the

controls specialist but all containment will be provided by the electrical sub-contractor.

3.38.1 Scope of works

The work shall comprise the following:

a. Liaise with all client staff, main contractor and other professional team members and any other parties as necessary throughout the contract.

b. Survey of existing electrical installation.

c. Disconnection, removal and disposal of all items of controls, switchgear, containment, accessories etc. made redundant by the new installation.

d. Test and retain existing supply from the existing intake room to the new distribution board including all new switchgear, distribution board and accessories etc.

e. Provision of any necessary supports/any necessary framework for new switchgear/isolation switches etc.

f. Supply and installation of all containment systems including containment for control wiring.

g. Supply and installation of boiler room power and lighting including emergency lighting.

h. Provision of temporary electrical supplies.

i. Labelling of all equipment including isolating switches etc. Labels shall be Traffolyte engraved and screw fixed with round head screws.

j. Earthing throughout to comply with BS 7671, including labelling/identification of cables and earth bars etc.

k. All associated builder’s work, making good and decoration.

l. Testing/commissioning of new services on completion.

m. Provision of all test certification and documentation.

n. Provision of information for inclusion in O&M manuals, see clause 3.42

3.38.2 Extent of Works

The controls specialist shall be responsible for the design and correct installation and the

proper working of the completed controls, electrical services installations (power and lighting)

will be carried out by the electrical sub-contractor, which comprise the works. In addition to

the complete and proper installation of the works, the contractor shall be responsible for:

a. Providing written method statements for all elements of the work including works duration times and service downtime, before works commence.

b. Taking delivery, unloading, handling, temporary storage and protection of all plant, equipment and materials.

c. Providing all specialist plant, equipment and tools necessary for erection and testing.

d. Installing and connecting all plant and equipment and ensuring that all associated work such as builders work etc., is properly executed.

e. Demonstrating that the complete installation is capable of the performance and method of operation specified.

f. Commissioning and testing the complete installation including making adjustments, calibrating etc., as necessary and making arrangements to enable the Clients Representative to be present during such commissioning and testing etc.

g. Providing maintenance instructions and complete sets of ‘as installed’ drawings of the completed installations.

h. Instructing the Client’s staff in the operation of the installation.


i. Providing information in the form of a simplified users guide.

j. Maintaining and keeping the installations in full working order and making good all defects or other faults during the specified periods.

All items of equipment, switchgear, accessories, conduits, trunking etc., shall be installed in

strict accordance with the manufacturer’s instructions.

3.38.3 Survey of existing installation

The Contractor will inspect all aspects of the existing installation in the areas affected by the

works in order to determine existing cable and trunking routes, existing holes through walls

etc. This will enable the contractor to accurately carry out all necessary new / replacement

of the existing systems in order to accommodate the new room layouts.

The survey shall:

• Identify all systems serving the boiler room and the four satellite plant rooms.

• Identify cable routes and any service not being part of the boiler plant and the four

satellite plant rooms but which passes through the rooms.

3.38.4 Normal services/temporary supplies

Normal services shall be disconnected for the minimum amount of time and electrical

services shall be tested and reused.

Temporary single phase supply shall be maintained whilst the works are in progress to feed

the temporary boiler plant see mechanical specification for details. Supplies to these items

shall only be disconnected whilst final connections are carried out.

The Contractor shall be deemed to have included in his tender for the supply, installation and

subsequent removal of any temporary cabling and equipment.

3.38.5 Particulars

Generally the electrical supplies shall be as shown in the following table:

Service No. Fed From Approx. Details

3 phase 30A TP&N switch fuse

1 Existing intake room Fused at 20A

Single phase MCB Board

1 30A TP&N switch fuse 100A switch disconnect 2x16A 2x6A MCB 2 x spare

New control panel 1 16A way in MCB board Single phase supply to control panel

Boiler room lighting 2 6A MCB way 1x500mm single fluorescent fitting with 3hr maintained emergency 1x28w 2D bulkhead 1x test key switch and normal (gang switch in grid) metal clad

Boiler room power 1 16A RCBO 1 x twin 13A metal clad switched socket outlet.

Items fed from Control panel

Pressurisation & fill unit

1 Fed from panel 230V 5amp


Boiler supplies 2 Fed from panel 230V 3x3 AMPs

Main pumps 2 Fed from panel 230V 5x3 AMPs

Gas Solenoid 1 Fed from panel 230V 6AMP

3.38.6 Wiring and Containment Systems

All containment shall be installed in strict accordance with the manufacturer’s instructions

and shall be complete with all conduit boxes, bushes, glands, couplers, joints, bends and

angle sections etc. to form a continuous containments system.

Under no circumstances shall the containment system be used as a CPC. All circuits shall

be supplied and installed complete with suitably sized CPCs.

Containment and cables shall be as follows:

Connection between new switchgear distribution board and panel:

Suitably sized LSF insulated single cables in suitably sized galvanised steel trunking mounted on walls.

Feeds to socket outlets: 2.5mm² + 1.5mm² CPC LSF insulated, single

cables with separate CPC installed in suitably sized galvanised steel trunking and/or suitably sized surface mounted galvanised steel conduit, mounted on walls and/or fixed to soffits.

Feeds to lighting: 1.5mm² + 1.5mm² CPC LSF insulated, single


Containment for control wiring: Suitably sized galvanised steel trunking

mounted on walls and/or fixed to soffits and/or suitably sized surface mounted galvanised steel conduit.

Control Wiring: 1.5mm² + 1.5mm² CPC LSF insulated, single


All items of boiler equipment must be provided with isolators and final connection carried out

in LSF heat resisted flexible cables in flexible metallic conduits. These flexible connections

must be kept to a minimum length and suitably fixed.

3.38.7 Labelling

All switchgear shall be labelled to indicate its duty.

All labels will be of the traffolyte ivorene type with 6mm high black lettering secured to all

specified equipment, etc., with the use of 2 no. brass nuts and bolts. The use of self-tapping

screws is prohibited. This shall include labelling the meters and denote the dwellings

served.

All isolators should be engraved to indicate function.


3.38.8 Earthing and Bonding

The contractor shall connect all circuit protective conductors of circuits fed from a distribution

board to an earth bar contained within the board.

All metal lighting, power outlet and switch boxes shall be bonded to the circuit earth

continuity conductor. When the fixing of an earth terminal within the box for this purpose is

not possible the following method shall be employed to effect a termination. A circular steel

earthing ring at lighting points or elsewhere the earth conductor shall be fitted with a

compression lug which shall be secured to the box in an approved manner.

All power outlet and switch boxes shall incorporate an internal brass earth terminal. All

sections of steel conduit trunking or tray shall be bonded to earth.

The contractor shall carry out all main equipotential and supplementary bonding of exposed

and extraneous conductive parts within the boiler room.

The contractor shall allow for the main equipotential bonding of all incoming gas, water,

pipes, etc. as necessary.

The connections on to the earth clamps shall be made with a suitable size of compressed

lug unless the conductor is looped and remains broken.

The metalwork of any water supply pipes above shall be earthed by a supplementary

bonding conductor from a power accessory item of electrical equipment.

All bonding conductors shall be mechanically protected up to a point immediately adjacent to

the bonding connection.

The means of protection for all bonding conductors shall be the same as that specified for

lighting and power final circuits.

Bonding connections onto conductive parts shall be made by either running a separate

conductor to each of the ‘parts’ or by looping the conductors between the ‘parts’ provided

that the conductor is continuous and unbroken at connections.

Where bonding connections are required to be made on a number of pipes (or similar) which

are located immediately adjacent to each other, the bonding conductor shall be installed in a

neat and unobtrusive manner between the bonds. A route between bonds which may

constitute an obstruction or the formation of loops of cable will not be permitted and the

conductor shall, wherever possible, be suitably secured in position. The cable shall be

secured, where necessary, to pipework by using plastic self-locking cable ties with surplus

ends of the tie cut back.

3.38.9 Mounting Heights

Mounting heights of accessories, etc, will comply with the requirements of Part M of the

Building Regulations. Dimensions being taken to the centre of the unit from FFL:

Distribution board & switch fuses: 1200mm to bottom edge

Isolators: Adjacent to equipment served but

not less than 450mm above f.f.l.

Flex Outlet Plate: Adjacent to equipment

The contractor shall advise the client’s representative of any problems in achieving the

mounting heights listed above prior to commencement of the installation.


3.38.10 General Testing of installations

The contractor shall carry out tests on the finished installation as described in the 17th

Edition of the IEE Regulations.

The contractor shall provide the Clients Representative with at least seven days prior notice

of testing such that the Clients Representative may be present to witness tests if desired.

Whether or not witnessed by the Clients Representative, full records of all test results shall

be completed at the time of testing and shall be available for inspection upon request.

Should the Clients Representative so request, the Contractor shall repeat any or all tests in

the presence of the Clients Representative at no additional cost to the Contract.

The contractor shall provide Completion and Inspection Certificates as described in the 17th

Edition of the IEE Regulations, duly completed with all test results, etc.

The contractor shall be responsible for providing all instruments and equipment necessary to

test the installation together with personnel sufficiently qualified and experienced to carry out

such tests.

Tests will be carried out where relevant in the following sequence:

.001 Continuity of ring final circuit conductors

.002 Continuity of protective conductors, including main and supplementary equipotential

bonding

.003 Earth electrode resistance

.004 Insulation resistance

.005 Insulation of site-built assemblies

.006 Protection of electrical separation

.007 Protection by barriers or enclosures provided during erection

.008 Insulation of non-conducting floors and walls

.009 Polarity

.010 Earth fault loop impedance

.011 Operation of residual current devices and fault voltage operated protective devices

The Clients representative will be at liberty to demand the use of any testing instrument or

apparatus that he may reasonably consider to be necessary in the execution of the testing.

In the event of the works being incomplete and causing a postponement of the notified

verification of test date or the installation failing to pass the test the Clients representative will

be at liberty to deduct from the contract price all reasonable expenses incurred by him in

attending the repetition of the tests.

The presence of electronic components will be noted clearly on the circuit charts and in

operating and maintenance manuals with an indication that testing procedures may result in

damage.

3.38.11 Commissioning

Commissioning will be carried out to verify the correct operation of the whole installation as

detailed in Clause 3.30.


Commissioning will be carried out in the following sequence of events for each and every

type of electrical service installed:

a. Setting the system to work.

b. Inspection of the system under operating conditions.

c. Demonstration to the Clients Representative and Client of the proper operation of the system and the control and safety devices under any fault condition.

d. A full load electrical test for a minimum period of one hour to record voltage and current for final circuits, sub-main and main intake positions.

Equipment fitted with batteries shall be protected to ensure that no damage is sustained by

the battery, battery charger or any other component during discharge or recharge of the

batteries when operating unattended.

3.38.12 Certification

On completion of the inspection, testing and commissioning procedures the contractor will

complete the following documentation and forward them to the Clients Representative for

comment:

(1) N.l.C.E.l.C. Inspection Certificate

(2) N.l.C.E.l.C. Completion Certificate

One copy of the aforementioned certification will be submitted within fourteen days of the

results being recorded.

Ultimately the certification will be included within the Operating and Maintenance Manuals.

All certification will be completed by a qualified and competent operative.

3.38.13 Provision of information for the operation and maintenance manual

The contractor shall maintain records on site and provided the following information for

inclusion in the operation and maintenance manual:

• A full description of each of the systems installed including their mode of operation

written to ensure that the Employer’s staff fully understand the scope and facilities

provided.

• Diagrammatic drawings of each system indicating principal items of plant, equipment

etc.

• The name, address and telephone number of the manufacturer of every item of plant

and equipment together with catalogue list numbers.

• Manufacturers’ technical literature for all items of plant and equipment, including

operating and maintenance instructions.

• A copy of Test Certificates for all items of plant and equipment used in the

installation.

• A copy of all manufacturer’ guarantees warranties and maintenance agreements

offered by sub-contractors and manufacturers.

• Emergency procedures, including telephone numbers for emergency services.

Where manufacturers or equipment are names in this Specification, the contractor will

submit his tender based on that named item.


3.38.14 Builders Works associated with electrical service

The contractor will be required to drill all holes and make good any holes made by the

removal of the existing switchgear, conduits and any trunking accessories etc.

3.38.15 Manufacturer

All equipment will be as follows:

1) Switch fuse Eaton

2) Distribution board Metal clad MCB board MK Sentry 3) Isolation & switches MK metal clad grid units 4) Luminaires 1500mm 3 hr maintained emergency

unit with polycarbonate Diffuser Thorlux 28w 2D Thorlux

5) 13A Twin switched socket outlet MK Metal clad range 6) Conduit Galvanised 7) Trunking Galvanised

3.38.16 Existing MICC riser

Should the existing MICC riser fail the test it will be replaced using a 6mm2 3 core XPLE

LSF armoured cable fed from the existing electrical intake cupboard. The existing 3 phase

supply will be changed to a single phase supply and the new 3 phase switch fuse detached

and a 30A single phase isolator provided.

A provisional sum has been allowed for this item.

3.39 BONDING

Bonding to mechanical items will be provided as necessary in accordance with BS7671.

3.40 SYSTEM PERFORMANCE TESTS

The whole heating installation shall be subject to system performance tests as detailed in the

standard specification.

3.41 SYSTEM CLEANING AND FLUSHING OUT

Prior to final commissioning of the heating systems, the whole system shall be thoroughly

flushed out (The secondary system is not to be power flushed), as described in the standard

specification. During the flushing process, strainers, pumps, meters, control valves,

instruments and any other items of plant which could become damaged by the cleaning

operation shall be excluded. Tanks shall be cleared of sludge and foreign matters.

The contractor will be required to submit a “system clean certificate”, which shall state the

following:

a. The date/year the system was cleansed/flushed

b. The product name and manufacturers details

c. Confirmation that the system has been flushed in accordance with the manufacturer of the cleaning/flushing agent.

Water Treatment (Inhibitor)

Upon completion of the new gas fired boilers primary and secondary circuits of the

installation and associated works shall be flushed and dosed as detailed below:

1. Fill and vent the complete heating system and the carry out a cold flush.


2. Drain down the system

3. Fill and vent the system again and carry out a hot flush.

4. Drain down the system again.

5. Fill and vent the system again and introduce the correct dosage of a suitable

corrosion inhibitor, as recommended by the boiler manufacturer.

The contractor will be required to submit a “water treatment certificate”, which shall state

the following:

a. The date/year the inhibitor was introduced into the system.

b. The volume of inhibitor introduced into the system

c. The product name and manufacturers details

The cleaning process and water treatment shall be in accordance with the manufacturer’s

recommendations and to the recommendations of the heating equipment suppliers. This

service, cleaner and inhibitor can be obtained from:

Aldous & Stamp Houseman Ltd Goodwater Ltd

86 Avenue Road The Priory 22-24 Ivanhoe Road

Beckenham Burnham Hogwood Lane Industrial Estate

Kent Bucks., Finchampstead

BR3 4SA SL1 7LS Wokingham

Tel. 0208 659 1833 Tel. 01628 604488 Berkshire

RG40 4QQ

Tel. 0118 973 8264

3.42 TESTING, COMMISSIONING AND PUTTING TO WORK

The Contractor shall carry out all tests on the controls, as may be prescribed by the clients

representative including the ability of starter to limit starting current and the satisfactory

functioning of all isolators, no-volt and thermal overloads wiring sequence, pilot lights etc.

The Contractor shall be deemed to have included in his tender a definite allowance for all

necessary testing, initial servicing, checking over, putting into commissioning and

demonstrating of the operation of all plant, including attendance by the respective

manufacturer of specific plant and equipment as details earlier.

The control panel shall be commissioned by the specialist control contractor on completion

of the works.

Allowance shall be made to demonstrate controls and all plant operation to the Client

Representative.

Prior to the application of the insulation all new pipework will be pressure tested.

The test periods shall be as detailed in the specification “Standards of Materials and

Workmanship – Mechanical”.

After the hydraulic tests have been carried out to the satisfaction of the Project Engineer the

system shall be flush cleaned, dosed and then functioned tested.

Upon completion of the new gas pipework serving the boilers, the complete installation (new

& existing) shall be tested, purged and put to work in accordance with The Gas Safety

(Installation & Use) Regulations and the Gas Safe requirements.

The Contractor will be required to provide a Gas Safety Record Certificate, for the complete

installation


All tests shall be carried out in the presence of the Project Engineer. The Contractor will give

a minimum notice of one week for all site tests requiring the Project Engineer attendance.

All testing equipment will be certified, calibrated and dated by an independent body The

Contractor shall be responsible for providing the required testing equipment.

Records of all the tests results, including test pressures, external and internal temperatures

etc., and gas consumption rates shall be kept and included in Operation and Maintenance

Manuals.

Any defects of workmanship, materials, performance or other regulations which become

apparent during the tests shall be rectified at the Contractor's expense

3.43 BUILDERS WORKS

The contractor is to allow for all necessary builders work requirements, and these shall

include at least the following in the three separate pricing elements of the works, see pricing

document.

a. Cranage, moving and lifting for equipment into position, removal of any existing plant etc. and installing of all the new installation.

b. All redundant plinths to be stripped out.

c. New Concrete plinths will be provided for the new pressurisation unit and possibly the control panel.

d. All new civil trenching and manholes (plus street grade covers and frames) for underground and maintenance required at all underground joints and branches and any valves if installed in ground

e. Remove unrequired existing bases, and the reinstatement of new required bases for plant room equipment

f. The necessary builders work within all flats for installing all services, plus all necessary making good and repairs to decoration to match existing surfaces where builders work or installation have damaged these areas

g. All exposed steel and new heating pipework shall be wire brushed and painted 2 No coats Red Oxide paint, prior to the application of thermal insulation. All new gas pipework shall be wire brushed painted with yellow Ochre paint.

h. Supply and install four new metal doors (one each) to the four satellite plant rooms, including locks, hinges, handles, paint, signage and associated works.

i. Make good holes in walls, floors and ceilings around pipes, cables and flues etc.

j. Remove and replace existing ducting as required. (see foot note below.)

k. Where pipework or ductwork passes through fire barriers, all holes shall be made good with intumescent mastic for a 2hr fire rated.

l. Where pipework, ductwork or boiler flue’s passes through the external wall, the Contractor will ensure that openings are made good with suitable weathering.

m. All necessary staged/phased carnage/hoisting etc. for the moving and lifting of equipment into position externally and internally within plant room to be allowed for, plus installing of all the new installation, and any/all necessary road closure requirements etc. for supplying and installing the entire works.

n. Protection to plant room, external areas and dwellings etc. during removal and install of all the works.

o. Pipe work within dwelling shall be boxed in where pipe runs exceed two pipes, or at high level, or vertically as to being unsightly and not aesthetically pleasing to the eye. High Level and vertical boxing must have the approval of the Contract Administrator prior to installation.


p. Upon the completion of the boiler replacement works the boiler room and the four satellite plant rooms floor are to be painted 2 coats Watco flexigrip slip resistant textured floor paint in tile red colour and paint walls and ceiling of entire plant room with one coat of watco industrial wall coating in white colour.

q. Access equipment scaffolding & hoist to allow the existing equipment etc. to be removed and all new equipment etc. to be installed.

r. Making good all areas following completion of works.

s. Cutting all necessary holes throughout the entire system.

t. Survey for the required removal of any asbestos. Actual removal if required by client.

u. Removal of all debris and cleaning of all areas worked in on site.

v. Provision of scaffolding for access installation.

w. Opening up and reinstatement of access for materials in and out route.

x. Landscape modifications to allow access for temporary heating system and deliveries, removal, reinstatement of bushes, protection of ground, removed temporary protection and reinstatement of fence and ground as detailed on site plan drawing.

y. Site set up site office, storage & welfare facilities including all Heras fencing etc.

z. Arrangements for all partial road closure, & full pavement closure.

Note: The existing and proposed route for the new pipe work runs directly under the

balconies outside each dwelling. The estate has recently had new access panels

fitted along these balconies covering the existing pipe work and isolation valves. The

contractor must take all necessary precautions to ensure that the panels are not

damaged and replaced back correctly throughout the duration of the project. The

contractor will be held responsible for any damage caused by the installation of the

new heating and hot water systems and will be required to make good any damage

and or supply and fit like for like at their own cost.

3.44 THERMAL INSULATION

All new and modified pipework with in all plant rooms shall be insulated throughout in

accordance with the standard specification “Standards of Materials and Workmanship –

Mechanical” and match existing. Also repairs to existing where disturbed or damaged during

the course of the works.

All exposed new LTHW and water pipework will be insulated with mineral wool, tied with

insulation bands and covered in “Hammerclad” aluminium sheeting. All pipes shall be

labelled for their service in accordance with the relevant BS standard.

All existing unaltered thermal insulation shall be replaced as required covered by

contingency sum located within the pricing document.

All new underground heating, hot and cold water pipework shall be pre-insulated as detailed

in clause 3.28.

All above ground heating, hot and cold water pipework in risers, branches and external to

flats, shall be insulated to levels indicated within the standard specification (section 3).

All pipework within flats, heating, hot and cold water shall be insulated [heating only where

not giving off beneficial heating into spaces with radiators], to levels within the standard

specification.

The cold water pipework above ground in risers, branches and within flats shall be vapour

sealed throughout.


All new and modified pipework within plant room shall be insulated with insulation in

accordance with the standard specification phenolic insulation and (in plant room) hammer

clad covering plus valve bags to all new and modified pipework risers to be the same

thickness weathered where necessary where not within boxing in.

Thermal Insulation – Underground Mains

All new and modified (other than pre-insulated) pipework shall be insulated in accordance

with the standard specification and match existing. Also repairs to existing where disturbed

or damaged during the course of the works.

All conventional above ground heavy grade steel heating pipework and fittings to be

insulated with rigid pre-formed mineral wool sections in accordance with British Standards.

Pre-insulated pipework will be used where the pipework:

1. Is installed below ground or in accessible trenches

2. Rises vertically up each necessary block.

3. Runs horizontally where necessary throughout project.

Provide hammerclad finish to all new pipework in plant rooms.

Provide identification banding in accordance with British Standards.

Provide and install new valve bags to all new valves within plant rooms. Bags to be

manufactured by:

Iso Covers Ltd., Trent Valley Industrial Estate, Station Road, Rogeley, Staffordshire, WS15

2HW

Tel. 01889 574333

Equal and approved:

Requirements for above ground

Pipe Size LTHW HWS Mineral Wool Phenolic Foam Mineral Wool Phenolic Foam

15 25 15 25 15 20 25 15 30 15 25 25 15 30 20 32 25 15 30 20 40 25 15 30 20 50 25 15 30 20 65 30 20 40 25 80 30 20 40 25 100 30 20 40 25 125 30 20 40 25 150 30 20 40 25 200 30 20 40 25 250 40 25 40 30

Flat surfaces 40 30 50 35

All new above ground pipework shall be insulated with foil faced rigid mineral wood sections

in accordance with:

• BS EN 253


• BS EN 448

• BS EN 489

• BS 4508

• BS 5422

• BS 5608

• BS 5970

• BS 7572

• BS 476

Requirements for below ground.

Soil Cover: 500mm

Distance between pipe jackets: 150mm

The pre-insulated pipework installed both above and below ground shall be of ‘series

1’ or ‘standard pipe’ specification and not as that defined within Southwark Councils

Standard Specification for Pre-insulated Steel Underground Heating Pipe.

3.45 OPERATING AND MAINTENANCE MANUAL (RECORD DRAWINGS)

The contractor shall provide electronic copies of the maintenance and operating documents

within six weeks of completing the works.

For details please refer to the Standards of Materials and Workmanship – Mechanical

Services (Section 2) and Electrical Services (Section 5).

Diagrammatic drawings, diagrams and wiring diagrams shall be include in this section

sufficient details to illustrate the design and installation principles of all systems.

Copies of the Maintenance and Operating documents shall be submitted to the Contract

Administrator for his approval before final hand over.

In addition to the above the `As-Fitted' drawings shall also be submitted for approval prior to

hand over. The drawings shall indicate the schematic layout and plant layout. The drawings

are to indicate the complete installation including the routes and sizes of all pipework and the

location of all isolating valves/cocks.

Schematic Drawing

In addition to the information above, the contractor shall include for mounting an boiler room

schematic drawing of the new mechanical services installation “AS INSTALLED” on the

boiler room wall, in a position to be agreed on site with the Project Engineer. The drawing

will located in a heat resistant vacuum sealed plastic cover a mounted in a frame.

The drawing must include all major items of plant, together with flow direction arrows and a

brief description / overview of the system operation.

The drawing format will be A2, laminated and framed. The title block shall include the

company’s name, address, telephone & fax No, the project title and the date of completion.


3.46 MAINTENANCE OF SYSTEMS

The Contractor is to include, within the installation price, the cost of an annual service for the

boiler installation. This service is to be carried out during the last four weeks of the defects

period and is to follow manufacturer’s instructions. This includes the cleaning of the

burner/injector, pilot and combustion box. Any defects found during this service are to be

reported to the Project Engineer and corrected before the end of the defects period.

The Contract Administrator shall be given two weeks’ notice of the proposed dates of

servicing.

The Contractor will be responsible for the maintenance of the new plant and equipment for a

period of twelve months from the date of completion.

The contractor shall also carry out the annual gas test on the gas supply system and issue

the client with the necessary gas certification.

3.47 SPARES

The Contractor is to allow for the following spares, within his costs, to be provided before

handover at Practical Completion:

Lubricants: 12 months’ supply of each type used in installation.

Special Tools: Full set of any special tools necessary to operate access and maintain installation. Tools to be properly labelled.

Valve Keys: 2 sets of valve keys of each type of valve used in the installation.

Chemicals: 12 months’ supply of each type of inhibitor etc., used in the installation.

3.48 DEFECTS PERIOD:

The contractor is to provide 24 hour response to any total heating failures for the full 12 months defects period.

3.49 ASBESTOS

An asbestos register is available for Meakin Estate, from the Leathermarket project engineer

and the contractor shall familiarise themselves [and all their operatives] with the contents

prior to the works.

Any suspected asbestos found [or assumed] shall be indicated to the Leathermarket project

engineer who will arrange for the asbestos to be tested and if required removed from site.

3.50 ELECTRICAL WARM AIR HEATERS

The contractor shall include in his tender to supply & deliver 1 No. 2kW electric warm air

heater for each of the 123 No. dwellings. The heater will be distributed if and when

requested by the Leathermarket project engineer; these shall be signed for by the occupiers.

The fan heaters will be ordered and to be stored on site or be available to issue within 4

hours on request.

The fan heater shall be a Glen Model No GF20TSN2 with 4 No. heat settings or equal & to

be approved.


3.51 SCHEDULE OF EQUIPMENT

Job No: 6682 Meakin Estate Equipment Schedules Equal or Approved

Item Make Model Quantity Comments

Boilers Potterton NXRi-16 2

Low Loss Header combined dirt separator Spirotech XC200F 1

Expansion Vaillant 140 litre heating expansion vessel

1

Pressurisation Unit Mikrofill ref: Q73689 Mikrofill 3200/4 1 12m head,1.5 bar cold fill pressure, 2.5 bar working pressure at 82 deg C

Gas solenoid valve Blacks technigas

Power seat BC66810FL4 230v 1

Gas Emergency button Blacks technigas

BC66ESB/P 1

Thermal cut out Blacks technigas

BC66-ETF 2

Gas monitor panel Electro control EGD-M 1 With gas detection and CO monitoring

Pumps 1&3 Shunt. Action pumps ref. APLQ32248

Grundfos MAGNA3 65-40 F 2 230-240v 1ph 50Hz.

Pumps 2&4 Primary Action pumps ref. APLQ32248

Grundfos TPE 100-250/2 Series 1000 2 Single head cast iron, 100mm flanged. 415v 3ph 50Hz 1.5kW variable speed. 22l/s @30kPa

Pumps 5&6 Primary Action pumps ref. APLQ32248

Grundfos TPE 100-70/4 Series 1000 2 Single head cast iron, 100mm flanged. 415v 3ph 50Hz 1.5kW variable speed. 36l/s @120kPa

Pump 7 secondary sub plant 1 Grundfos Model to follow 1




Safety valves. Nabic ref: Q630280 Nabic N500AHAAA032 2

Heat meters (HW) DMS JSC90-NK 4 (R160) 3/4" Pulsed HW Meter

123


Heat meters (HTG) DMS 749 QPI 1.5 123

Hot water heating Rycroft Breeze 4 More information to follow

Buffer Vessels Rycroft 4 More information to follow

SECTION FOUR

STANDARDS OF MATERIALS AND WORKMANSHIP – ELECTRICAL

THE MATERIALS AND WORKMANSHIP DETAILED IN THIS SECTION APPLY EVEN IF NOT DETAILED IN THE RELEVANT PARTICULAR REQUIREMENTS SECTION

4. SECTION FOUR ................................................................................................................................... 1

STANDARDS OF MATERIALS AND WORKMANSHIP – ELECTRICAL ............................................. 1

4.1 GENERAL ............................................................................................................................................. 1

4.2 REGULATIONS ..................................................................................................................................... 1

4.3 ELECTRICITY SUPPLY ........................................................................................................................ 2

4.4 IDENTIFICATION AND NOTICES ........................................................................................................ 2

4.5 CONNECTIONS TO EXISTING CIRCUITS .......................................................................................... 2

4.6 INSTALLATION OF SWITCHGEAR ..................................................................................................... 2

4.7 DISTRIBUTION BOARDS ..................................................................................................................... 3

4.8 MINIATURE CIRCUIT BREAKERS (MCB’S) ........................................................................................ 3

4.9 MOULDED CASE CIRCUIT BREAKERS (MCCB’S) ............................................................................ 3

4.10 FUSES ................................................................................................................................................... 4

4.11 AIR CIRCUIT BREAKERS (ACB’S) ...................................................................................................... 4

4.12 CONTACTORS ..................................................................................................................................... 4

4.13 CABLES AND GENERAL REQUIREMENTS ....................................................................................... 4

4.14 XL-LSF SINGLE CORE CABLES ......................................................................................................... 6

4.15 FLAT XL-LSF AND SHEATHED CABLES ............................................................................................ 6

4.16 MINERAL INSULATED COPPER CONDUCTED CABLES ................................................................. 7

4.17 XL-LSF INSULATED AND SHEATHED STEEL WIRED ARMOURED CABLES ................................. 9

4.18 FLEXIBLE CABLES AND CORDS ...................................................................................................... 11

4.19 CABLE TRUNKING SYSTEMS ........................................................................................................... 12

4.20 CABLE TRAY ...................................................................................................................................... 13

4.21 PVC MINIATURE TRUNKING ARRANGEMENT ............................................................................... 14

4.22 STEEL CONDUIT AND CONDUIT FITTINGS AND ACCESSORIES ................................................ 15

4.23 GENERAL INSTALLATION ................................................................................................................. 17

4.24 CONCEALED CONDUIT SYSTEMS .................................................................................................. 18

4.25 FLEXIBLE METALLIC CONDUIT........................................................................................................ 19

4.26 PVC CONDUIT AND FITTINGS .......................................................................................................... 20

4.27 FIXINGS .............................................................................................................................................. 20

4.28 PAINTING ............................................................................................................................................ 21

4.29 FINAL CIRCUITS ................................................................................................................................ 21

4.30 LUMINAIRES ....................................................................................................................................... 22

4.31 LABELS AND CIRCUIT CHARTS ....................................................................................................... 22

4.32 EARTHING AND BONDING ............................................................................................................... 23

4.33 TESTS FOR HIGH VOLTAGE SYSTEMS .......................................................................................... 25

4.34 EARTH ELECTRODE ......................................................................................................................... 26

4.35 MANUFACTURER’S RECOMMENDATIONS .................................................................................... 26

4.36 INSPECTION AND TESTING ............................................................................................................. 27

4.37 OPERATING AND MAINTENANCE ................................................................................................... 28

4.38 HANDOVER ........................................................................................................................................ 29

Z:\WP\DMP\JOB\DMP\6658\Spec\G Section 4 Standard Electrical.docx 1

4. SECTION FOUR

STANDARDS OF MATERIALS AND WORKMANSHIP – ELECTRICAL

4.1 GENERAL

The Clauses described within this Section of the Specification refer to the standards of

materials and installation techniques that are to be followed. The Clauses are intended to

provide general guideline only and should be considered as a minimum standard acceptable

to the Contract Administrator. Should any discrepancies occur between Clauses in this

Section and the Particular Section, the Particular Section Clauses shall be adhered to.

The Contractor’s attention is particularly drawn to the requirements of BS 7671:2008 the 17th

Edition of the IET Wiring Regulations, Chapter 13, wherein only good workmanship and

proper materials will be used.

The installation of all electrical works will need to be undertaken by an Electrical Contractor

who is a registered Member of the National Inspection Council for Electrical Installation

contracting and/or will also be a member of the Electrical Contractors Association. The

Electrical Contractor will need to satisfy all requirements as necessary including Building

Regulations i.e. Part ‘P’, for domestic installations.

Where, in the opinion of the Contract Administrator, this has not been complied with the

Contractor will remedy the installation accordingly to the Contract Administrator’s

satisfaction.

4.2 REGULATIONS

The materials and installation procedures, which will be used throughout the Contract, will

comply with the recommendations of the current Editions, including amendments of the

following:

a. Wiring Regulations for Electrical Installations published by the Institute of Engineering Technology BS 7671:2008

b. British/European Standards and British/European Standards Code of Practice issued by the British Standards Institution.

c. The Factory Acts.

d. The Electricity Supply Regulations.

e. The Electricity at Work Regulations

f. The Health and Safety at Work Act 1974.

g. The requirements of the local Fire Protection Officer.

h. The requirements of the local Electricity Board.

i. The Gas Safety Supply Regulations.

j. The relevant Local Authorities.

k. The Construction (Design and Management) Regulations 2015.

l. The relevant Building Regulations.

m. The Control of Asbestos Regulations 2012.

n. Electricity Safety, Quality and Continuity Regulations 2002.

o. The Clean Air Acts

p. The Energy Conservation Act.


Suitable qualified operatives maintaining the current working practices shall carry out the

installation.


4.3 ELECTRICITY SUPPLY

The Contractor shall be responsible for the co-ordination of the electrical services with those

of the Supply Authority.

4.4 IDENTIFICATION AND NOTICES

Each conductor shall be identified at its terminations and preferably throughout its length to

indicate the phase to which it is connected (reference BS 7671:2008, Clause 514).

Binding and sleeves for identification purposes shall comply with BS 3858 where

appropriate.

Any identification of switchgear including a switchboard busbar or conductor shall comply

with the requirements of BS 7671, Table 51 so far as these are applicable.

Warning notices (including ‘Electrical Installation Condition Report’), Diagrams, Charts or

table or equivalent form of information shall be provided in accordance with BS 7671:2008

(Clause 514).

4.5 CONNECTIONS TO EXISTING CIRCUITS

Where connections are to be made to the existing mains supply system no alterations shall

be undertaken until first obtaining the approval of the Contract Administrator.

The work shall be executed in such a manner and at such times as may be necessary in

order to cause the minimum of interference with existing services.

Where is may be necessary to interrupt existing services, notice of such intention shall be

given by the Contractor to the Contract Administrator in advance to enable any necessary

arrangements to be made. The notice given shall be 2 days for minor disruptions and 1

week for disruption for over 4 hours.

4.6 INSTALLATION OF SWITCHGEAR

Where individual items of switchgear are specified in the same location, they shall be

grouped together or where it is suitable grouped together in a purpose made panel.

All apparatus shall be independently fixed of the wiring system.

All wiring shall be enclosed within a trunking and conduit system with no through wiring

passing through any items of switchgear.

All trunking shall be provided with purpose made metal end plates and additional fixings as

necessary.

No operating handle will be mounted at a height greater than 4.1 m A.F.F.L.

Surface mounted switchgear to be installed in a flush installation shall be installed over a

suitably sized adaptable box. A suitable opening shall be formed in the rear of the panel for

cable access.

Flush mounted switchgear to be installed within the building fabric shall be designed so as to

allow full removal and replacement of all items within the panel without the requirement to

damage the wall finish.

Lids shall be fully openable.


Within flush mounted distribution boards, where possible additional conduits shall be

provided into the ceiling void/service duct to allow for future expansion. Minimum 2 no.

conduits for each service and size provided complete with draw wire.

4.7 DISTRIBUTION BOARDS

Distribution Boards shall be of the miniature circuit breaker type complying with BS EN

60529:1992 + A2:2013 and BS EN 61439-5:2011. They shall have a fault withstand

Classification of Class 1.

Each neutral bus-bar shall have an outgoing terminal for each circuit breaker type complying

with BS EN 61439-5:2011 and BS EN 60529:1992 + A2:2013 as appropriate with a degree

of protection not less than IP2XC. They shall have a fault withstand Classification of

Class 1.

Each neutral bus-bar shall have an outgoing terminal for each neutral conductor connected

to it. Connections to the neutral shall be arranged in the same order as the outgoing live

circuit conductors.

Bus-bars shall be in the same position relative to their fuse carriers or MCBs for each pole.

A multi-terminal bar for the circuit protective conductors shall be provided for both insulated

and metal cased boards with one terminal for each outgoing circuit. It shall be directly

connected to the earthing terminal without depending on the exposed conductive parts of the

enclosure.

Identification of each fuseway and MCB way shall be by numbering. Identification on the

neutral bus-bar and protective conductor shall clearly relate each terminal to its respective

fuseway/MCB or RCBO way.

Number of spare fuse/MCB/RCBO ways shall be provided where indicated. If not indicated

a minimum 20% spare ways shall be provided. Where specific ratings are indicated,

fuses/MCB’s/RCBO’s shall be incorporated, otherwise the ways shall be left blank but

suitable for future additions.

Distribution boards are to include an integral, suitably rated switch.

Phase barriers shall also be fitted as necessary.

4.8 MINIATURE CIRCUIT BREAKERS (MCB’S)

Miniature circuit breakers (MCBs) shall be complete with suitable voltage and ratings

selected in accordance with the size of sub-circuit wiring in accordance with the IET Wiring

Regulations. They shall be either single or triple pole and shall comply with BS EN 60898

latest edition and amendments.

Unless stated otherwise, miniature circuit breakers shall have a minimum rated breaking

capacity of M6. Combined MCB/RCCB (Residual Current Circuit Breaker) with over current

protection (RCCBO) shall comply with BS EN 61008-1:2012 + A2: 2013. Unless stated

otherwise all RCCBO units shall be of type C characteristics and set at 30MA tripping

sensitivity.

4.9 MOULDED CASE CIRCUIT BREAKERS (MCCB’S)

Moulded case circuit breakers shall comply with BS EN 60947-2:2006 + A2:2013 (Latest

editions and amendments). They shall have the voltage and current ratings, rated duty,

rated short circuit breaking capacity and rated short time to withstand current as required in

accordance with the IET Wiring Regulations.


MCCBs shall be of the independent, manual closing air breaker type, rated for an

uninterrupted duty unless otherwise indicated.

Auxiliary facilities including power closing and under voltage releases shall be provided only

where indicated.

Each MCCB shall have a facility for padlocking in the ‘OFF’ position.

4.10 FUSES

The type and current rating of fuses shall be as required and/or indicated.

Cartridge fuse links complying with BS 1361 shall by Type 1 fuse carriers, bases and

associated parts shall also comply with BS 1361 (latest additions and amendments).

Cartridge fuse links complying with BS 88 shall have a fusing factor of Class Q1 unless

otherwise indicated.

Motor circuit fuse links shall by used only where indicated or where necessary.

Fuse carriers, bases and associated parts shall also comply with BS 88.

4.11 AIR CIRCUIT BREAKERS (ACB’S)

Air break switches shall comply with BS EN 60947. They shall have uninterrupted duty, a

mechanical endurance not less than those set out in the relevant table(s) of BS EN 60947,

and utilisation category of AC-22 or AC-23 as indicated.

Switches shall meet the requirements of switch-disconnectors.

Each switch shall have a facility for padlocking in the ‘OFF’ position.

4.12 CONTACTORS

Contactors shall comply with BS 5424 & BS EN 60947-4-1:2010 + A1:2012. They shall be

air-break type and have the voltage and current ratings, type of duty, utilisation category and

electrical endurance as required.

Contactors shall be electromagnetic, suitable for the control arrangements as required.

Operating coils shall be suitable for D.C. and a rectifier shall be incorporated for A.C. control

circuits, protected by low current cartridge fuses.

Latch-in contactors shall be provided only where indicated.

4.13 CABLES AND GENERAL REQUIREMENTS

All cables shall be of the low smoke and fume (LSF) type with thermosetting insulation (XL).

All cables will have copper conductors, unless specified otherwise, and comply with the

appropriate British Standard Specification, and BASEC approval. Where applicable, type

and size of cables will be as specified on the Drawings and Schedules.

Unless otherwise specified, no cables of less than 1.5mm² C.S.A. will be used. The use of

solid core cables is prohibited (unless flat 6242Y or 6243Y cables are being used). The

cables shall be installed without joints.

Unless particularly detailed in this Specification or Drawings, cables will not run through

lighting fittings.


Cables shall be coloured as follows:

Phase cables on single-phase circuits: Brown

Phase cables on three phase circuits: Brown, Black, Grey corresponding to the

phase to which it is connected

Neutral cables throughout: Blue

Low voltage cables: Brown

Circuit Protective Conductor: Green or Green/Yellow

Every cable and flexible cord shall bear the following markings to signify that it’s a product of

authenticity:

a. Manufacturers Origin Mark – all cable should bear a manufacturers name.

b. British Standard Number – by marking the cable with this standard number, the manufacturer has confirmed conformity to this standard. This amounts to a claim by or on behalf of the manufacturer that the product meets the requirement of the standard. The accuracy of this claim is solely the claimants and it should not be confused with 3rd party accreditation.

c. BASEC Marking – this is only allowable if the cable has been tested by BASEC and continues to meet the surveillance requirements.

d. Harmonised Cable Mark and Harmonised Designation – as a part of the pan European CENELEC harmonisation scheme, these markings denote that the cable is harmonised. HAR is a voluntary mark which signifies a quality code.

e. Conductor Size – the cross sectional area of the copper conductor.

f. Year Letter – a letter attributable to the year of manufacture.

g. Origin of Manufacture – country of origin.

h. Harmonised Core Colours.

All cables used in the installation shall be based certified.

The cables and seals will be intact when delivered on site. No coil, cable or flexible cord

manufactured more than one year prior to delivery on the site shall be used in the

installation.

Before wiring the conduit/trunking enclosure shall be complete, free of dirt, water and

condensation.

Where cables are concealed in flush conduits the cables will be installed easily via draw

boxes so that the cables can be withdrawn or rewired without disturbance to the building

fabric.

Cables will always be so bunched that cables of all phases and neutral are drawn into the

same conduit.

The conduit cable capacities laid down in Appendix 5 of the On Site Guide will be strictly

adhered to.

All cables shall be installed in strict accordance with BS 7671 (17th Edition), latest edition

and amendments.

The installation of cables shall not commence until the building is sufficiently enclosed to

ensure permanently dry conditions. Cables shall be adequately protected at all times during

the contract period against accidental damage, adverse environmental conditions,

mechanical stress and deleterious substances.


Cables shall be installed neatly and securely without joints other that at equipment and

terminal fittings. Junction boxes shall not be used without approval from the Contract

Administrator.

No reduction of cable strands forming the conductor shall be allowed at switch or other

terminals. All strands shall be efficiently secured by screws, nuts and washers or other

approved means.

All cable lengths stated on the drawings or in the cable schedules are for design purposes

only and shall not be used for Tender or Construction. Unless stated otherwise, specified

three phase cable groups or single core cables shall be laid in trefoil formation and touching

each other. During installation no cable shall be bent to a radius smaller than the minimum

recommended by the manufacturer.

4.14 XL-LSF SINGLE CORE CABLES

All XL-LSF single core cables will be protected throughout their length by heavy gauge

conduit mini trunking or steel trunking.

All single core cables will have copper stranded conductors and for normal conditions will be

XL-LSF insulated.

The XL-LSF cables will fully comply with BS 7211:2012 and will be of 600/1000V rating.

4.15 FLAT XL-LSF AND SHEATHED CABLES

These cables will be copper conducted XL-LSF insulated and sheathed, twin and earth or

three core and earth conforming to BS 7211:2012 and BS 6346: 1997.

The use of cables with phase conductors having a cross-sectional area of less than 1.5mm²

is prohibited. Where 2.5mm² XL-LSF insulated and sheathed cables are used, the circuit

protective conductor will not have a cross-sectional area of less than 1.5mm².

Wiring will be carried out on a "loop-in, loop-out" system with all cables terminating directly

within main switches, distribution boards, etc., socket outlets, luminaires and switches only.

Joints made within junction boxes and the use of through joints will not be permitted.

Cables will be concealed as far as possible in accessible roof spaces and under floors,

where they will be run parallel, or at right angles to all joists, etc.

Cables in the roof void will be secured to the sides of the joist by means of plastic cable clips

at not more than 250mm centres and will be secured to battens when running across the

joist.

All cables will be installed not less than 100mm clear of any gas, heating, hot water or steam

pipes, radiators or other heated fittings, except where the pipe or fittings are effectively

insulated and, in this instance, a 10mm air gap will be provided between the insulation and

the cables.

All cables will be dressed flat; will be free from twists, kinks and mechanical strain.

Cables shall be installed to satisfy the requirements of BS 7671:2008 (latest amendment)

and Part P of the Building Regulations for installations within domestic premises.

The conduit shall run from a position inside the accessory box and will extend into the floor

or roof space for at least 50mm. The conduit will terminate in the accessory box by means

of a PVC adapter and screwed male bush.

PVC adapters/accessories for non-metallic conduits.


The ends of the conduits will be finished so as to prevent abrasion of the cable installation

when cables are being drawn into or out of conduits or connected to apparatus.

Cables passing through walls or concrete floors will be enclosed in PVC conduits.

Where it is not possible to conceal the cables in walls, etc., they will be installed on the

surface, but in these instances, surface mounted conduits or mini trunking will protect them.

Cables terminating at ceiling switches or luminaire points will terminate within a standard

besa box complete with fixed earth terminal and 51mm fixing centres, complying with BS

4568-1:1970 & BS EN 61386-1:2008.

Where standard besa boxes are installed within plaster ceiling they will be securely fixed to

wooden noggins provided and installed by the Contractor a sufficient height above the ceiling

to permit the face of the box to be flush with the finished ceiling surface.

Where wall or ceiling mounted luminaires and ceiling mounted switches are installed the

fixed wiring will terminate directly into the accessory terminals.

4.16 MINERAL INSULATED COPPER CONDUCTED CABLES

Where M.I.C.C. cables are specified within this Specification and/or on the accompanying

Tender Drawings, this will mean mineral insulated copper sheathed cables manufactured in

accordance with BS 6207-1: 1995 & BS EN 60702-2:2002 + A1:2015 and all relevant later

amendments.

Generally cables will be light duty, rated at 600V, and may be used for fire alarms, general

lighting and small power circuits. Heavy-duty cables, rated at 1000V, will be used for all

other services.

Cable terminations will comply with the requirements of BS 6207-2:1995 and comprise ring

type glands, screw on pot type seals, cold plastic compound suitably for temperatures up to

105°C, anchoring bends and neoprene sleeving. The Contractor will terminate M.I.C.C.

cables in an approved manner and procedure recommended by the cable manufacturer.

All seals and lengths of M.I.C.C. cable shall be tested not less than 24 hours after

completion with a megger insulation test at a pressure not less than 500 volts. Nothing less

than an infinity reading must be obtained between any conductors and the cable sheath, all

conductors being disconnected from any apparatus. All M.I.C.C. cables requiring to be

"covered up" shall be tested before and after "covering up".

The specified tools recommended by the manufacturer will be used throughout the

installation.

The Contractor at their cost will rectify low insulation resistance readings due to faulty cable

termination procedures.

Before proceeding with the installation of MICC cables the Contractor may be required to

demonstrate to the Contract Administrator the ability on their site personnel to apply a

complete termination to one end of an installed cable.

All conductor tails will be marked with coloured sleeves of an approved pattern to identify the

conductors.

The colours used will be in accordance with the recommendations of the latest Edition of the

IET Regulations.

Sub-main cable conductors will be marked with coloured sleeves indicating the colour phase

they originate from.


All M.I.C.C. cables will be securely fixed by single or multiple heavy gauge saddles to the

surfaces of the walls, ceilings, ducts, etc., by 25mm No. 6 round head brass screws.

Where several cables are installed together multiple saddles shall be used only.

Where cables are to be supported onto a perforated cable tray the fixing screws will be

round head brass to comply with BS 450 and the securing nuts will be of the brass square

pressed type complying with BS 2827.

The spacing of saddles or clips will not exceed the distances indicated below:

a) Cables up to 9mm overall diameter single or multi-bank: 230mm b) Cables of over 9mm diameter up to 12mm overall diameter, single or

multi-bank: 300mm c) Cables of 12mm overall diameter and greater, single or multi-bank: 375mm d) Multi-bank saddles containing cables of various sizes, will be directed on

site by the Contract Administrator but on no account will they exceed: 375mm

Cable bends will not be less than six times the diameter of the cable. At terminations, there

will be at least 75mm of straight cable at the gland position.

Where surface cables rise through floors to serve an accessory point, the cable will be

protected through the floor up to a height of 2M above f.f.l. with heavy gauge galvanised

conduit. The space between the cables and conduit in each instance will be filled with cold

setting mastic compound.

Where cables pass through any structure, e.g. walls and floors, these cables will be

protected by heavy gauge galvanised conduit provided with female brass bushes at either

end of the conduit.

M.I.C.C. cables provided with a PVC outer sheath would be provided to the following

exposed corrosive atmospheres:

a. Damp situations, i.e. externally run cables.

b. Boiler houses/plant rooms.

c. Service ducts.

d. Embedded within plaster or floor screeds.

e. Secured to cable trays.

f. In areas specifically specified within the specific section of this Specification and Contract Drawings.

Where PVC sheathed cables are installed a PVC shroud will also be employed.

All cables will terminate directly into main switches, BS besa boxes, socket outlet boxes and

fixed apparatus only.

No joints will be allowed in joint boxes, nor will any through joints be allowed, unless as

specifically instructed by the Contract Administrator.

Where M.I.C.C. cables terminate directly into luminaires or BS besa boxes to which

luminaires will be directly attached, high temperature sleeving will be used to protect the

conductors.

Where M.I.C.C. cables terminate within accessory boxes in damp situations the boxes will be

of the watertight pattern with tapped thread entries, external fixing lugs and machine faced


lids. The lids will be rendered watertight by means of waterproof jointing compound or

rubber gaskets. In no circumstances will it be permissible to drill boxes internally for fixings.

Where surface mounted run M.I.C.C. cables terminate within a plain hole accessory box, i.e.

switch, socket outlet or distribution board, etc., the cable will terminate with the use of

internally threaded space ranger glands provided with brass locknuts and zinc plated

lockwashers (where applicable).

M.I.C.C. cables terminating direct to apparatus which will be subject to vibration or which is

adjustable, i.e. motors or pumps will be formed into a double turn loop coil immediately prior

to the termination.

Where M.I.C.C. terminates within PVC accessory boxes suitable earth tail pots or earthing

rings shall be used to ensure earth continuity.

4.17 XL-LSF INSULATED AND SHEATHED STEEL WIRED ARMOURED CABLES

Where XLPE/SWA/LSF cables are specified within the specific section of this Specification

and/or indicated on the accompanying Tender Drawings. This will mean PVC insulated and

sheathed steel wired armoured cables.

All XLPE/SWA/LSF cables are to be of the 600/1000 volts grade, unless otherwise specified,

and will comply with the requirements of BS 6346:1997 for copper cables.

The conductors will be of high conductivity copper wire (unless specified otherwise) insulated

with PVC compounds, the cores laid up with PVC textile filler, PVC sheathed or textile

bedded, armoured with a single layer of galvanised steel wire and PVC serviced overall.

Cores shall be identified as follows:

Twin core cable - One core brown and one core blue

Three core cable - One core brown, black and grey

Four core cable - One brown, black, grey and blue

All cables shall be installed in one length without intermediate joints. The minimum

installation temperature is 0°C. If cables are being installed during sub-zero temperature

conditions, they should be stored at a temperature above freezing point for at least 24 hours

immediately prior to handling.

Each cable shall be marked at both ends with white ivorene or traffolyte engraved labels

denoting cable size.

The ends of all cables shall be terminated by means of compression type glands complete

with earth terminating rings and PVC shrouds. These glands shall be of the same

manufacture as the cable.

The earth terminating rings will be securely bolted to the electrical apparatus with the use of

brass round headed screws and nuts complying with their respective British Standards.

Within the electrical apparatus an earth fly lead will extend from the earth ring with the use of

crimp lugs and terminate within the earth terminal of the apparatus.

Cables shall be installed throughout with the greatest possible care and any damage caused

to the cable during installation or the progress of the work will necessitate the rejection of the

cable and the replacement and re-erection of a corresponding new length by the Contractor

free of charge.


Where cables are to be run on the surface they shall be supported by means of claw type

cleats, as manufactured by BICC Ltd, or equal and approved, and the spacing of the

supports must not be greater than those given in the following Tables:


Overall Diameter of Cables *

Non-armoured

rubber, PVC or lead sheathed cables

Armoured cables and corrugated aluminium

sheathed cables.

Mineral insulated

copper sheathed or aluminium sheathed

cables

Horizontal Vertical Horizontal Vertical Horizontal Vertical

Not exceeding 9 250 400 600 800

Exceeding 9 but not 15 300 400 350 450 900 1200

Exceeding 15 but not 20 350 450 400 550 1500 2000

Exceeding 20 but not 40 400 550 450 600




Exceeding 70 and above

1000 1400 1200 1400

* Normal practice is to consult the cable manufacturer about support spacing on

cables exceeding 40mm diameter. The space for horizontal runs may be applied also to

runs at an angle of more than 30º from vertical. For runs at an angle of 30º or less from the

vertical, the vertical spacing is applicable. In long straight heavily loaded power cable

installations, either loop the cables at suitable intervals or increase the cable spacing by a

factor of 1.5. Where the appearance of the cable installation is not important, the spacing

could similarly be increased by a factor of 1.5.

Where the cables pass through walls or floors of fire zones the holes shall be filled with fire

resisting infill after the installation of the cables.

Each cable shall be protected from mechanical damage to a height of 2 m above floor level,

where run on the surface of walls.

Where cable access to buildings is required the cables shall be run in short lengths of glazed

earthenware or PVC cable ducts to ensure that the cables are not damaged when drawn into

the duct. The entry point is sealed to prevent ingress of moisture and vermin.

The Contractor will allow for all abnormal brackets required for cradle support on site. The

Contractor will also allow for drilling of installed steelwork to take the studs for the cleats.

Cables will not be bent during installation to a radius smaller than eight times the overall

cable diameter.

Cables will be segregated from the finished face of other services by a minimum distance of

75mm, unless as instructed by the Contract Administrator.

Cables laid directly in the ground will be installed to a depth of not less than 600mm below

finished ground level.

In normal soil the cable will be laid on 100mm of sand and covered with a minimum of

150mm of sand and taped over its entire length underground. The Contractor must include

for supplying and laying of the same and protection tape, the latter to be laid at a depth of


300mm below ground level. The protection tape shall have the following words printed

thereon:

"CAUTION - ELECTRIC CABLES BELOW"

Before the cable is finally covered the Contract Administrator will be invited to inspect the

cable along its entire length.

Where cables are to be run under paths, paved roadways or enter buildings, they will be

drawn into earthenware ducts which shall be provided and laid by the Contractor to a depth

of not less than 600mm, below finished ground level. All duct terminations in buildings will

be made with the use of manufactured easi bends.

Cables shall also be protected by earthenware ducts where they cross the route of the other

services, to a minimum of 600mm each side of the crossing points.

Purpose made concrete cable markers laid flush with the finished surface will be supplied

and installed by the Contractor to indicate cable routes.

The use of underground cable joints will only be permitted by written instruction by the

Contract Administrator or specifically called for within the specific section of this Specification

and/or Tender Drawings.

All underground cable joints shall be made by a proficient cable jointer using cast iron joint

boxes and suitable resin compound to the strict recommendations of the cable manufacturer.

4.18 FLEXIBLE CABLES AND CORDS

Flexible cords in dwellings will be 300 volt grade single phase and in all other instances will

be 300/500 volt grade single and three phase complying fully with BS 6500:2000.

Conductors will be plain annealed copper strand for PVC cords and will be tinned annealed

copper strand for elastomeric cords.

The conductors will be insulated with PVC (HR), EPR or silicone rubber.

Cores will be laid up and the interstices filled where necessary with suitable filling for the

working temperature of the cable and sheathed with PVC (HR), HOFR hypalon or CSP.

Flexible cables will be of circular type.

The cores of each flexible cable will be identified as follows:

NUMBER OF CORES

FUNCTION OF CORES

COLOUR(S) OF CORE

2 3

4 or 5

Phase conductor Neutral conductor Phase conductor Neutral conductor Protective conductor Phase conductor Neutral conductor Protective conductor

Brown Blue Brown Blue Green & Yellow Brown or Black Blue Green & Yellow


The weight supported by any flexible cord shall not exceed 3 kg for 0.75mm² or 5 kg for

1.5mm².

Where excessive temperatures may be encountered with the use of tungsten coiled lamps

mounted within luminaires, PVC flexible cords shall conform to BS 6500:2000 (latest edition

and amendments).

4.19 CABLE TRUNKING SYSTEMS

The cable trunking used throughout the installation will be manufactured from galvanised

sheet steel and constructed to conform with the requirements of BS 4678 including Part

4:1982 (latest edition and amendments).

Trunking sizes up to and including 150mm x 50mm, or equal, cross-sectional area is to be

produced from 1.2mm minimum thickness sheet steel, above these sizes 1.6mm minimum

thickness sheet steel will be employed.

Cover lids will be fastened to the trunking body with turnbuckle screws rigidly secured to the

inwardly turned flanges on the trunking body.

All straight trunking joints will be made with the use of purpose made coupler connectors

secured with electro-tinned screws, nuts and shake-proof washers.

Trunking accessories will comprise gusset type bends, tees and angles of similar gauge,

type and manufacturer as the trunking body.

All trunking and accessories will be provided with a hot dip galvanised finish to comply with

BS EN 10143:2006.

Fabrication of any components on site is prohibited and only the manufacturers listed

accessories will be accepted.

All trunking will be made continuous electrically and mechanically by means of copper links

across each joint on the system. The galvanising material will be removed within 6mm of the

jointing strap to ensure good earth continuity.

Vertical sections of trunking will be provided with pin racks at not more than 2M intervals.

Continuous sheet steel segregation barriers will be provided, securely fixed to segregate

final sub-circuits and ancillary circuits, i.e. telephone and door porter systems.

Purpose made fire barriers shall be inserted into sections of trunking at points of entry and

exit from roof spaces between rooms and floors.

Where trunking passes through holes in the building structure, a cover plate will be fixed to

the face of the trunking before installation and will be arranged to project at least 50mm

beyond the finished structure.

Where trunking is to be used to connect switchgear or fuseboards, such connections will be

made by trunking fittings manufactured for this purpose and not by multiple conduit coupling.

Due allowance shall be made for expansion on long lengths of installed trunking.

The cable trunking will have a total air space of 66% giving a cable carrying capacity of 34%

within the internal area of the trunking.

All trunking will be rigidly attached to the building fabric at intervals not exceeding the

following Tables:


Cross-sectional Area Of Trunking Maximum Distance Between Supports For Metal Trunking

Horizontal Vertical

Exceeding 300mm² and not exceeding 700mm² 750mm 1000mm




Exceeding 5000mm² 1500mm 2000mm

Fixings will be provided within 300mm intervals of all bends, angles and fittings. Small

individual pieces of trunking will be independently supported accordingly.

All trunkings will be fixed by means of round head wood screws of sufficient size and length

to obtain a firm fixing into the building structure with a minimum length 32mm x No. 10

screws. The fixing screws will be zinc plated (electro-galvanised) complying with BS EN ISO

2081:2008 and BS EN ISO 2082:2008.

Each final sub-circuit contained within trunkings will be taped at 600mm intervals with two

laps of good quality transparent tape with additional wrapping at bends.

Circuit identification tapes will be attached under one layer of transparent tape at 4M

intervals.

4.20 CABLE TRAY

Cable trays shall comprise of perforated steel pre-galvanised manufactured to BS 2989

bending and profiling quality.

The cable tray shall have return flanges and comprise of the following thickness:

Up to & including 100mm wide - 0.9mm



Above 300mm wide - 4.0mm

The tray shall be galvanised for internal applications unless indicated elsewhere in the

Specification.

The cable tray accessories to be installed shall be of the same specification as the cable

tray.

All joints shall be made using manufactured fishplates, shouldered ends and couplers with

galvanised or zinc plated slotted domed head roofing bolts.

All flat bends and intersections shall be of the gusseted type.

The tray shall be supported by purpose made galvanised brackets at intervals not exceeding

1200mm and 230mm from all fittings and with a minimum 20mm clearance behind the cable

tray.

The brackets shall be securely fixed to the building fabric using suitably sized masonry plugs

and screws. The screws shall be zinc plated (electro galvanised) complying with BS EN ISO

2081:2008 and BS EN ISO 2082:2008 Class B coating and be no less than 32mm x No. 8 in

size.


The tray shall be fixed to the galvanised brackets using zinc plated slotted domed head

roofing bolts.

Cable tray shall only be cut along a line of plain metal and all cut edges of galvanised cable

tray shall be prepared and treated with a zinc rich paint, primer and top coat.

Holes cut in cable tray to allow cable to pass through shall be suitably bushed.

The cables shall be fixed to the tray by means of proprietary form of plastic or copper cable

clips, saddles, strips or ties. When installed in situations where high temperatures or humid

conditions are likely to occur copper or brass saddles and clips shall be used.

All saddles, clips, straps, etc., shall be fixed to the tray by means of brass screws or nuts and

bolts.

4.21 PVC MINIATURE TRUNKING ARRANGEMENT

PVC miniature trunking will be of the high impact quality conforming to the requirements of

BS 4678: Part 4:1982.

PVC trunking and accessories will not be installed where the temperature falls below -5°C or

exceeds 60°C.

The trunking will be fixed at centres not exceeding 300mm by means of round head steel

screws of sufficient size and length to obtain a firm fixing into the building structure with a

minimum size of 32mm x No. 8 screws.

Each section of trunking will be fixed not more than 32mm from each end, corner or

accessory.

All cutting of trunking will be neat, clean and square and the manufacturers purpose made

junction units, connections, tee angles and joints will be used to the complete satisfaction of

the Contract Administrator.

All trunking will be run between final positions of accessories, walls, ceilings, etc., and will

not terminate in mid run despite reduction in the number of cables. Where necessary high-

level trunking will be extended in dummy lengths from the ends of cable runs to the next

change of direction of wall and/or ceiling.

Trunking will be run close to corners of the room, building structure, chimney breast corners,

built-in corners, etc., and the general finish will be as unobtrusive as possible. It is

preferable to run the trunking in an adjacent bedroom or other room in order to avoid

trunking runs in the Living Room.

Where the trunking turns at right angle in the dwelling the junction will be made in an

approved manner or a manufactured junction used, so that the turn is made without cutting

the back of the trunking.

Trunking will only be run vertically or horizontally.

After final installation of all lids, the trunking will be cleaned using a mild detergent.

Where trunking runs are obstructed by picture rails small simple cornices, etc., the

obstructions will be neatly cut to fit close to the sides of the trunking and, where necessary,

the cut obstruction will be re-fixed. Where an item that cannot be cut obstructs the trunking,

then the trunking will terminate either side of the obstruction and the cable recessed behind

the obstruction.

At all terminations purpose made adapters are to be used-switches, socket outlets, fused

spur units, cooker control units, immersion heater (adaptable box), etc.


At lighting points however a shallow moulded box will be used, together with a break joint

ring made from white plastic, robustly constructed and provided with suitable cable entries

and ample room for slack cable.

Where cable runs pass through walls, a suitable length of size of PVC trunking or conduit will

be run through the wall and be cemented into the base of the trunking on each side of the

wall. No trunking or oval conduit will be visible when the installation is complete.

The number of cables enclosed in PVC miniature trunking will not exceed the following:

Trunking Size 1.5mm² T & E x L-

LSF T&E XL-LSF

2.5mm² T&E

XL-LSF

16mm x 16mm 1 8 - 7

16mm x 25mm 2 14 1 11

16mm x 38mm/40mm 3 24 2 19

25mm x 38mm/40mm 42 4 33

PVC miniature trunking will be spaced as far as practical from steam, water, gas or other

services with a minimum clearance of 50mm between services. Where installed PVC

miniature trunking are located in close proximity to other services, the trunking will be

provided with a heat barrier and securely fixed to avoid contact.

4.22 STEEL CONDUIT AND CONDUIT FITTINGS AND ACCESSORIES

All steel conduit and conduit accessories used throughout the installation will be

manufactured by comply with the requirements of BS EN 61386-1:2008, the Specification for

Steel Conduit & Fittings with Metric Threads of ISO Form for Electrical Installations, Steel

Conduits, Bends & Couplers, Fittings & Components, together with all amendments.

All steel conduits will be heavy gauge screwed and seam welded medium protection Class 2

for stove black enamelled type conduit and Class 4 hot dipped for galvanised type conduit.

All steel conduits to be installed will not be less than 20mm diameter and will not exceed

32mm diameter unless specifically specified within this Specification or as indicated on the

Contract Drawings or by written instruction by the Contract Administrator.

All steel conduits and conduit accessories, i.e. fittings, adaptable boxes, saddles, etc., will

match the type of conduit specified and will be of the same manufacturer.

Each steel conduit installation where applicable will be installed to comply with the

requirements of BS EN 61386-1:2008:, BS EN 61386-21:2004 + A11:2010 and BS EN

61386-24:2010.

Conduit screw threads will be of the ISO Form and will be cut by means of efficient sharp

stocks and dies. Under no circumstances will broken or loose threads be accepted.

Where practicable, all threads will be half the length of the appropriate standard straight

coupler and no thread will be exposed, except at "running couplers". In these instances the

exposed threads will be painted immediately after installation.

All threads will be cleaned and free from oil prior to installation and all threads will be

thoroughly clean and free from paint, enamel, dirt, grease, etc. All steel conduits will be free

from rust patches and mechanical damage on delivery to site. The steel conduits will be

stored in a dry and secured area to maintain an acceptable quality as previously specified.

All conduit threads will be cut "wet" with high conductivity graphite paste or metallic paste

having a non-insulating binder.


4.22.1 Circular Conduit Boxes

BS circular boxes will be manufactured from malleable iron with internal dimensions 60.3mm

diameter x 28.5mm depth and cover fixing lugs at 50.8mm centres. Each box will be

provided with a tapped hole in the base of the box for a M4 earth screw.

BS circular boxes will be fitted with a flat circular steel cover plate fixed by 2 No. round raised

head M4 screws. Where the boxes are flush mounted, the cover plate will be of the

overlapping type.

Where BS circular boxes are installed to external areas, moisture and semi-exposed

situation each box will be provided with a rubber gasket sited between the outer ring of the

box and the cover lid.

All BS circular boxes will be fixed to the building fabric by means of 2 No. round head screws

of sufficient size and length to obtain a firm fixing into the building structure with a minimum

length of 32mm x No. 8 screws. The fixing screws will be zinc plated (electro-galvanised)

complying with BS EN ISO 2081:2008, BS EN ISO 2082:2008 Class B coating.

4.22.2 Adaptable Boxes

Adaptable boxes will be manufactured from heavy gauge rust proofed mild steel, fully welded

seams and heavy gauge flat flanged lids. The width gauge will be as follows:

Boxes up to 150mm x 150mm x 75mm: 14 gauge

Boxes up to 355mm x 354mm x 100mm: 12 gauge

Each box will be manufactured with plain sides necessitating drilling of holes on site; the use

of knockout boxes is prohibited.

Adaptable boxes installed to external, moisture and semi-exposed areas will be galvanised

and provided with rubber gaskets situated between the outer face of the box and the lid.

All adaptable boxes will be fixed to the building fabric by means of 4 No. round head screws

of sufficient size and length to obtain a firm fixing into the building structure with a minimum

length of 32mm x No. 8 screws. The fixing screws will be zinc plated (electro-galvanised)


Earthed steel barriers will be provided where necessary to suitably segregate services.

4.22.3 Conduit Distance Saddles

Surface mounted steel conduit will be rigidly secured to the building structure with the use of

heavy gauge distance saddles provided with 2 No. M4 metric roundhead brass screws

securing the saddle clip to the base ensuring the conduit standards not less than 6mm clear

from the building surface.

Each distance saddle will be fixed to the building structure by means of 1 No. counter-sunk

screws of sufficient size and length to obtain a firm fixing into the building structure with a

minimum length of 32mm x No. 8 screws. The fixing screws will be zinc plated (electro-

galvanised) complying with BS EN ISO 2081:2008, BS EN ISO 2082:2008 Class B coating.

Distance saddles will be provided within 300mm either side of each steel conduit bend or set

and at a maximum distance of 900mm between saddle centres for straight sections.

Where conduit boxes, accessories, etc., are situated distance saddles will be provided

300mm either side from the centre of the box.

The Contractor will carefully arrange the layout of the saddles to achieve an even

workmanship and aesthetically pleasing appearance.


4.22.4 Conduit Spacer Bar Saddles

Surface mounted steel conduit will be rigidly secured to the building structure with the use of

heavy gauge spacer bar saddles provided with two No. M4 metric roundhead brass screws

securing the saddle clip to the base.

Each saddle will be fixed to the building structure by means of 1 No. counter-sunk screws of

sufficient size and length to obtain a firm fixing into the building structure with a minimum

length of 32mm X No. 8 screws. The fixing screws will be zinc plated (electro-galvanised)


Saddles will be provided within 300mm either side of each steel conduit bend or set and at a

maximum distance of 900mm saddle centres for straight sections.

Where conduit boxes, accessories, etc., are situated saddles will be provided 300mm either

side from the centre of the box.

The Contractor shall carefully arrange the layout of the saddles to achieve an even layout.

4.22.5 Accessory Boxes For Steel Conduit Installations

Each accessory box will be manufactured from pre-coated galvanised steel to comply with

BS 4662:2006, + A1:2009 Specification for boxes for the enclosure of electrical accessories.

Each accessory box will be suitable for recessed mounting within the building structure and

will be provided with ample knockouts for conduit entry.

Each accessory box will be provided with robust tapped accessory fixing lugs to accept M2.5

metric screws. One fixing lug will be adjustable to enable true alignment of the fixed

accessory.

The minimum depth of all accessory boxes will be 35mm unless as instructed by the


Each accessory box will be fixed to the building structure by means of a minimum of 2 No.

roundhead screws of sufficient size and length to obtain a firm fixing into the building

structure with a minimum length of 32mm x No. 8 screws. The fixing screws will be zinc

plated (electro-galvanised) complying with BS EN ISO 2081:2008, BS EN ISO 2082:2008

Class B coating.

All recessed accessory boxes will finish flush with the finished surface (within practical

limits). Under no circumstances may the accessory box finish proud of the finished surface.

In the event that the final location of the front edge of the accessory box is 16mm or greater

from the finished surface. The Contractor will supply and install an extension box to allow

the accessory box to finish flush with the finished surface. The use of extension screws in

these instances is prohibited.

4.23 GENERAL INSTALLATION

The conduit and conduit accessory installation for each sub-circuit and final sub-circuit will

be completely erected prior to the installation of any circuit wiring.

During construction of new built projects the building will be made watertight prior to

commencement of any conduit installation. Additionally circuit wiring may only be drawn into

the conduit installation upon completion of the wet trades, e.g. plastering.

The conduit will be installed at least 150mm clear from all other services wherever possible

and must not come into contact with water, gas, heating or steam pipework.


Where conduits are specified to be installed in voids above suspended ceilings, they shall be

fixed to the structure using the recommended method of fixing, e.g. saddles.

The complete conduit system will be electrically and mechanically continuous including all

boxes, etc.

All conduits will be reamed clean internally to ensure freedom from burrs and other defects.

All conduits will be installed in straight lines with easy bends or sets to harmonise with the

architectural features of the building.

The use of diagonal runs is prohibited; all branches will be sub-divided at right angles.

All conduits to be set will be bent cold without damaging the overall section with an approved

bending machine and former. The use of manufacturer bends, etc., is prohibited unless as

instructed by the Contract Administrator.

Draw in points will be spaced at a maximum of 8M centres and not more than two 90° bends

(or equivalent) will be permitted.

Where conduits pass through structural floors, walls, etc., over sleeves will be provided. The

sleeve will take the form of a larger size steel conduit.

Open BS boxes, etc., will be suitably protected to avoid the ingress of concrete, plaster slurry

or any other material.

Running couplers will be used where absolutely necessary. All running couplers will be

locked together by means of ring locknuts.

All conduits forming the couplers will be butted together inside the coupler.

In instances where a conduit is to be connected to the back of a besa box. The besa box will

first be drilled clear. A male brass bush will be inserted between the box and connect onto

the conduit coupler from inside the box to ensure a rigid mechanical and electrical

connection is achieved.

Recognised good engineering practice shall be adopted throughout and no conduit shall run

in such a way as to provide a trap for moisture or condensation. Precautions shall be taken

to prevent the ingress of moisture, silt, brick and concrete chippings, etc., during and after

the installation of the conduit system. Stopping plugs shall be fitted to the ends of all

conduits not connected to fixing and outlet boxes. Where condensation has occurred the

conduits shall be thoroughly dried by drawing swabs through them. The inside of all

conduits shall be free from burrs or other obstructions.

Where conduits are installed side-by-side all "off-sets" will be similar and where "off-sets" are

necessary at switch boxes, distribution boards, etc., these will be as short as practically

possible.

Under no circumstances shall conduits from different distribution boards be connected at the

same junction box.

The exact routes of all conduits and locations of all besa boxes, adaptable boxes and the like

will be indicated on the working drawings produced by the Contractor.

Unless otherwise indicated herein, the installation shall be carried out in accordance with the

IET Regulations and conform to the relevant British/European Standards.

4.24 CONCEALED CONDUIT SYSTEMS


Conduits that are to be cast in concrete floors will be laid directly above, but not in contact

with, the lower steel reinforcing bars before the floors are poured. Conduits or boxes cast

into structural floors will be of spout type securely fixed by the Contractor before pouring

starts and all boxes will be positioned to allow for the correct thickness of finishing.

Extension rings will be used on all ceiling outlets where the box is not flush with the finished

surface.

In circumstances where a terminal box would normally be used, the Contractor is to fix a

through type box with the spare spout plugged with a screwed brass stop so as to provide a

secure anchorage.

In special or pre-fabricated floor construction where the conduits cannot be installed as

described above, they shall be run in or upon the pre-fabricated sections and 'set' down into

'loop-in' type boxes. In the case of certain pre-fabricated floors it may be necessary for the

Contractor to withhold the installation until the structural cement topping on the pre-

fabricated section has been laid and set. In this event, the Contractor shall, prior to the

laying of the topping, mark accurately the positions of all points and down drops so that

preformed holes may be left.

A space of 13mm shall be left between adjacent conduits where they are to be covered with

plaster, cement or the like.

At expansion joints of cast in-situ concrete the conduit shall terminate flush at one side of the

joint in a screw to slip solid coupler. From the other side of the joint the conduit shall bridge

the expansion gap to engage the slip section of the coupler to allow not less than 13mm

movement of the conduit without separation.

An insulated flexible earth continuity conductor of cross sectional area not less than 2.5mm²

shall be installed within the conduit between boxes on either side of the expansion joint and

secured to the back of the boxes with M2 metric phosphor bronze screws and Ross

Courtney connectors.

Circular boxes shall not be used in flush systems solely for the purpose of 'drawing-in' cables

except by permission of the Engineer.

Where besa boxes are recessed into the walls or ceilings and flush with the finished

surfaces, the box lids will overlap the diameter of the box by not less than 6mm.

Conduits in wall chases will be secured to the building structure by means of heavy gauge

crampets at least 40mm long.

4.25 FLEXIBLE METALLIC CONDUIT

Flexible metallic conduit complying with BS EN 61386-1:2008 shall be used for the final

connection of the rigid conduit to the terminal boxes of machines fitted with a means of drive

adjustment and/or where vibration is likely to occur.

Flexible conduit shall also be provided to semi-portable equipment such as cookers, washers

and similar machines where a limited amount of movement is required for cleaning and

maintenance purposes. This does not apply to small machines normally connected to

socket outlets by flexible cables.

Unless specified otherwise, galvanised and non-watertight type flexible conduit shall be used

under normal conditions, but watertight flexible conduit shall be used where exposed to the

weather or is likely to be splashed or subjected to heavy moisture conditions.

In all instances the conduit shall be terminated in the approved type glands by being

screwed and finally hot soldered into same.


Flexible conduit will not be permitted in lieu of sets and bends in the rigid conduit system.

The flexible conduit shall be PVC sheathed, of ample capacity for the number of cables and

have a minimum length of 300mm with sufficient length to allow the full range of withdrawal,

adjustment or movement necessary.

4.26 PVC CONDUIT AND FITTINGS

All PVC conduit and accessories will comply with the requirements of BS 4607: Part 1:1984

+ A2:2010 and Part 5:1982 + A3:2010 Specification for Rigid Conduits, Fittings &

Components of Insulating Materials.

The conduit shall have a minimum size of 20mm and be rigid high impact heavy gauge

grade continuous drawn type and welded into the accessories.

The method of installation will conform rigidly with the manufacturers instructions and

recommendations, particularly ambient temperatures of areas where the installation is being

carried out.

Bends and sets in conduits up to and including 25mm will be bent cold with the use of the

correct size bending spring.

With the use of larger size conduits, the application of heat in an approved manner will be

used until such times that the conduit is pliable.

All joints between conduits and accessory boxes shall be watertight and jointed by the use of

PVC solvent adhesive as produced by the conduit manufactured.

Terminations of conduits into accessory boxes, etc., will be by means of female thread push

in adapters and PVC male bushes, or by FAB.FIBO or equal and approved accessories. All

accessory boxes, etc., will be of the metallic type with a zinc plate or aluminium finish. PVC

accessory boxes will be used only as instructed by the Contract Administrator.

The Contractor shall ensure that all conduits are free from internal obstructions and the full

diameter of the bore is maintained throughout its length.

Failure to comply with this requirement will mean the Contract Administrator will have the

right to order the conduit installation to be dismantled and removed as far as considered

necessary and replaced with new conduits. Conduit showing signs of strain or kinking shall

not be installed.

Such work will be carried out by the Contractor at no cost to the Employer.

At lighting points where excessive heat may cause loss of fixings the method of attachment

of the fixings shall prevent heat transmission or metal boxes shall be used and earthed via

the CPC.

PVC tube ends and flexible covers will be provided to prevent the ingress of concrete plaster

slurry into the conduit and fittings.

A separate circuit protective conductor will be installed in all conduit section, terminating

within a purpose made earthing terminal of the accessory.

4.27 FIXINGS

The Contractor will be responsible for the fixing of all equipment and accessories which shall

include the supply and installation of all rawl plugs and other plugs, bolts and rawl bolts,

screws, suspensions, brackets, clamps, saddles, spacers, etc., and any other fixing whether


or not specified, which may be required for the proper and effective fixing of material or

equipment. The use of wooden plugs for fixing purposes will not be permitted.

The Contractor will supply and fix all timber grounds and noggins required for the electrical

installation.

Fixings by means of hardened steel pins driven in by percussion tool (HILTI or similar) or by

gun fixing techniques will only be allowed where specifically agreed in writing by the Contract

Administrator.

Fixings to steelwork, etc., by means of special preformed spring clips or brackets will only be

carried out after approval has been obtained from the Contract Administrator steelwork must

not be drilled.

Where goods or materials are supplied by Nominated Suppliers, the Contractor shall include

for receiving, unloading, storing, providing adequate protection from the elements,

unpacking, hoisting as necessary, assembling, positioning and fixing.

The Contractor will allow in his tender for the fixing of any wall mounted starters and control

gear, etc., which may be supplied by the equipment manufacturer separate from the

machines.

4.28 PAINTING

General:

Painting work connected with the Electrical Contract is to be carried out by the Contractor,

except where otherwise detailed in this Specification.

Prior to handing over the installation to the painters, the Contractor is to remove all oil, dirt

and other foreign matter from the conduits, equipment or plant. Failing to do so will render

the Contractor liable for the cost of redecoration, should this become necessary.

Where painting is to be carried out by the Electrical Contractor due care will be taken not to

mark the surrounding finishes, the paint will be applied in a professional manner. All iron

and steel materials, including conduits, switchgear, brackets and accessories which show

signs of rust will be wire brushed clean and painted with one coat of Jenolite rust remover

and neutraliser, one coat of grey chemical sealer and one coat of red oxide paint prior to

erection.

The Contractor will allow for painting the intake panel framework, trunking and all equipment

mounted thereon, including all remote switchgear and controls with two coats of "NO

RUSTO" aluminium finish paint as Soligmum Ltd or approved equal, and one coat of paint,

colour as specified.

4.29 FINAL CIRCUITS

Every final circuit will be connected to a separate way of a fuseboard, switchfuse or circuit

breaker.

The wiring of each final circuit will be electrically separate from every other final circuit.

Generally, no more than two conductors may be bunched in any one terminal unless

necessitated by the type of installed system, and except for ring final circuits, may more than

one conductor be connected to a protective device sited within distribution equipment, i.e.

consumer units etc.

Neutral conductors shall be connected to the neutral bar at the fuseboard in the same order

as the live conductors.


At termination points such as switch or socket outlets, etc., sufficient length must be left on

cable ends to ensure that there is no tension on the connections.

The conductor insulation must be removed for a minimum length to facilitate connections

and no excess length of exposed conductor shall be left.

When preparing cable ends, the Contractor shall ensure that none of the conductor strands

are damaged and the strands will be twisted together with pliers to ensure a neat firm

connection.

The circuit requirements are indicated on the Tender Drawings and the Contractor shall

ensure that the circuits are wired strictly in accordance with these requirements.

4.29.1 Single Phase Circuits with 3 Phase Supplies

Single-phase lighting and power circuits shall be connected on the same phase in any given

area. The exception being as follows:

Where a large connected load on a common level the electrical load shall be equally

balanced over the 3 phases. However, accessories and supply points on different phases

shall be kept to a minimum distance of 2m apart.

Multi-gang lighting switches with 400 volts present shall be fitted with a grid clearly indicating

that 400V is present. The Contractor shall however endeavour to avoid this situation

wherever possible.

Where accessories are required to be on different phases within a given area this will be

referred back to the Contract Administrator for clearance, and in these instances, the phase

and voltage present shall be displayed on the equipment by means of an engraved traffolyte

label.

Final connection of luminaires by heat resisting flexible cord/sleeving.

4.29.2 Identification of Conductors

All conductors throughout the installation shall be identified by means of durable markings

which uniquely identify all conductors which make up individual circuits (eg: phase, neutral

and earth for each circuit).

4.30 LUMINAIRES

The Electrical Contractor will supply, install and terminate the circuit wiring to luminaires of

the type indicated by the Reference Letter or Luminaires Schedule marked on the drawing or

accompanying this Specification.

All luminaires (inclusive of ceiling roses and batten holders etc.) will be inclusive of lamps.

Wiring through luminaires is prohibited unless as otherwise specified or agreed with the


4.31 LABELS AND CIRCUIT CHARTS

Labels:

All switchgear, control gear and distribution boards mounted within electrical intake

cupboards/positions shall be provided with white ivorine or traffolyte labels engraved in 5mm

block letters filled black, securely fixed to the equipment drilling and fixing either by PVC

expanded rivets or brass headed screws and nuts.


Each label will denote the function of the equipment served. Three-phase equipment will

also be labelled to denote the voltage. Labels will be as described above except lettering

shall be red in colour.

In commercial intake positions the labels will denote the identification number/letter of

equipment, current rating, polarity, circuit being served and description of circuit for example:

L2

60 Amp S P & N (Phase Colour)

serving D.B.3.

First Floor Landing

Labels to distribution boards shall denote the identification number/letter, number of ways,

current rating, polarity, description of circuits being fed, location of supply cable, for example:

D.B.3

8 way 15 Amp S P & N (Phase Colour)

First Floor Landing

served from L2

Labels shall also be provided to all remote isolators, starters and push button units to

indicate the equipment being installed.

Additional labels shall be provided as specified elsewhere in this Specification.

All labels and final titles shall be approved by the Contract Administrator prior to engraving.

Circuit Charts:

A comprehensive typed Circuit Chart will be provided for each distribution board, consumers

control unit installed. The Circuit Chart will detail a full description of the circuits that are

being served, inclusive of fuseway number and MCB/fuse rating.

The Chart will consist of a white covered card enclosed within a transparent non-flammable

PVC. or approved sheet cover, secured to the equipment by means of 4 No. brass screw

fittings.

Where it is not possible to install the Charts within the distribution board, a hardwood-glazed

frame will be mounted beside the board enclosing the Chart.

4.32 EARTHING AND BONDING

The whole of the electrical installation and all other equipment connected thereto will be

earthed in conformity with the IET Regulations and to the requirements of the Supply

Authority.

The Contractor will install a suitably sized earth copper bar, protected against corrosion for

the termination of all main earth leads and main bonding cables including, where specified,

earth tapes used for the earthing of the main cubicle panels and lightning protection

schemes.

The earth bar fixings shall be suitably spaced off the building fabric and be complete with a

removable link for testing purposes.


The incoming supply authority's earth lead either from the incoming cable sheath or service

head shall be connected to the main earth bar so as to allow this earth lead to be isolated

when the link is removed.

A label engraved "Main Earthing Terminal" will be located adjacent to the earth bars.

Where the supply authorities services exist and the main earth connection is obtained from

the cable sheath. The Contractor shall ensure that the cable sheath is connected to the

consumer's main earth bar by means of XL-LSF insulated cable. The size of the cable shall

be dependant on the size of the supply authorities service head.

The following services where applicable shall be bonded to the main earthing terminal by

means of cupinned lugs, nuts and bolts and labelled to denote size and destination:

a. Incoming gas service.

b. Incoming water service.

c. Incoming oil service.

d. Structural steel works.

e. Rising mains - hot and cold services.

f. Fire hydrant services or dry riser.

g. Lightning protection system.

h. Intake room switchgear/panels and other earth bars.

The complete trunking, tray, conduit and accommodation systems including the sheaths of

all MICC cables will be electrically continuous and connected securely to all conduit boxes,

switchgear and distribution boards and other electrical apparatus forming part of the

installation.

The armouring and metal sheathing of all XLPE/SWA/LSF cables shall be solidly bonded

together and finally connected to the panels serving the cables.

The earthing continuity of the metal sheath of each sheathed cable shall be maintained by

efficient bonding of the main switch, switch fuses, distribution boards or other metal clad

accessories or appliances at which the cable terminates.

If there is more than one entry of any of the above services into each building, or each

separate dwelling forming part of a building, then each entry must be bonded.

The earth bonding connection will be made as near as practicable to the point of entry,

except in the case of the gas service where the connection shall be on the consumers side

of the meter, and must in all cases be in such a position that it shall be easily accessible for

inspection.

The earth bonding lead shall be XL-LSF insulated cable coloured green/yellow and enclosed

in either PVC. or HG steel conduit installed as indicated on the Drawings and Specific

Specification. This cable must be of continuous length of minimum size in accordance with

the relevant I.E.T Tables and the Supply Authority's requirements for PME.

All switchgear and sub-distribution panels will be bonded to earth as previously described.

Bonding clamps complying with BS 951: 2009 complete with a permanent label indelibly

marked with the words "SAFETY ELECTRICAL EARTH - DO NOT REMOVE", used

throughout the bonding installation.

Where flat XL-LSF insulated XL-LSF sheathed wiring systems are installed the CPC will

terminate directly into the outlet point.


The earthing terminal of each outlet position will be connected to the earthing terminal within

the accessory box mounted thereon with a short fly with a cross sectional area equal to the

circuit served circuit protective conductor.

At distribution boards the Contractor shall ensure CPCs are terminated to the correct

earthing terminal corresponding to the phase and neutral connections.

Where flat XL-LSF insulated XL-LSF sheathed wiring systems are installed the CPC will

terminate directly into the outlet point.

4.33 TESTS FOR HIGH VOLTAGE SYSTEMS

High voltage tests on HV cables and, where indicated, factory built assemblies and

transformers shall comply with the requirements for site testing in the appropriate British

Standards.

Inspection:

Works and equipment shall be inspected to ensure that it is satisfactory and safe to proceed

with testing and commissioning procedures. Particular attention shall be paid to the Safety

Standards for HV installations.

Testing:

Earth electrode tests shall be carried out before and after pressure testing, on both primary

and secondary circuits, using a 1000-volt instrument. Tests shall be accompanied by

certified copies of Certificate of Type tests. Tests shall be in accordance with the relevant

British Standards for transformers, switchgear and protective devices. Site tests shall be

carried out on completion of the erection and installation of the whole of the equipment.

Consist Of The Following:

a. Operating tests, power frequency tests, millivolt drop tests complying with BS EN 62271-1:2008 + A1:2011 (latest edition and amendments).

b. Power frequency tests, millivolt drop tests complying with BS EN 60265-1:1998 (latest edition and amendments).

c. Primary and secondary injection tests.

d. Insulation resistance tests to BS 7671 (latest edition and amendments).

e. Continuity tests of inter-panel cabling.

Pressure tests applied to all main connection for a duration of one minute at a frequency of

50Hz. If tests of a longer duration are carried out, the pressures should be decreased as

follows:

Duration of Test (Minutes)

Percentage of 2 x Service Voltage

1 100.0

2 83.5

3 75.0

4 70.0

5 66.6

10 60.0

15 57.7

DC Pressure tests, in accordance with Manufacturer’s recommendations applied to all HV

cables.


Checks to ensure correct phase sequence.

Comprehensive trip test of all equipment for all equipment at 50% services voltage, before

finally making the system live.

Setting To Work:

Before commencing the setting to work procedures, a full set of certified test reports must

have been completed.

Equipment shall be collectively set to work and shall include checks of control function,

mechanical and electrical interlocks and relay settings.

Commissioning:

Shall consist of showing that the complete integrated system shall function in all respects as

the total intent and within the design parameters.

4.34 EARTH ELECTRODE

The type of earth electrode used shall be appropriate to the soil type into which the electrode

is placed.

Generally in clay type soils copper or copper clad steel rods shall be driven vertically to a

minimum depth of 3 metres.

Soil containing chalk, limestone or rock sub-soil it may be necessary to lay a copper tape or

cast iron/copper plates.

The earthing conductor shall not be less than 25mm x 3mm annealed copper strip.

Joints shall be made using an approved process or bolted, riveted or clamped. The

Contractor shall ensure that copper jointing surfaces are twined.

Copper connections to iron earth plates shall be bolted and brazed with all bolts, rivets and

clamps made of brass, bronze or similar non-ferrous material.

Joints and electrode connection shall be readily accessible and enclosed within purpose

made inspection pits. Where access is not possible these joints shall be protected against

moisture ingress.

Tapes shall be of soft high conductivity copper, tinned unless otherwise indicated and where

fixed and liable to corrosion they shall be served with corrosion resisting tape or coated with

corrosion resisting sheath. Where the tapes are run in the ground they shall be laid in sand

and protected with tiles.

A removable test link shall be provided inside the building as near as possible to each earth

electrode for isolation of the earth electrode for testing purposes.

The Contractor shall obtain test readings of the earth electrode in dry weather conditions and

submit the results to the Contract Administrator.

Where copper tape is fixed to the building structure it shall be by means of purpose made

corrosion resistant saddles. Fixings shall be made using purpose made plugs and clamps

and installed at intervals not exceeding 1.0m.

All fixings shall be suitably corrosion resistant.

4.35 MANUFACTURER’S RECOMMENDATIONS


All equipment incorporated into the works shall be installed fully in accordance with the

manufacturer’s requirements. Upon request, the contractor shall provide the

Consultant/Contract Administrator with all manufacturers Certification.


4.36 INSPECTION AND TESTING

The whole of the installation shall be inspected and tested on completion in the presence of

the Contract Administrator in the manner described in the IET Regulations. The Contractor

will provide the necessary labour, material and instruments for carrying out these tests and

shall give the Contract Administrator seven days notice of the date it is proposed to carry out

the test.

The following inspections shall be carried out during the whole of the Contract:

a. General work standard and site inspection.

b. Equipment free from rust, damage and dirt.

c. Visual inspection of electrical equipment.

d. Electrical information/literature on any equipment being installed including labelling and Circuit Charts.

Prior to any wiring being commenced earth continuity tests shall be carried out to trunking,

cable tray and conduit installation to ensure that the resistance figures are acceptable.

These figures shall be submitted to the Contract Administrator for acceptance.

Visual checks are to be made of overload settings of all starters which should be set in

relation to the full load rating of the motors they control.

The Contractor will also allow for testing the installation whilst work is in progress, or as

instructed by the Contract Administrator, and in particular the following tests must be carried

out:

a. In the case of concealed sections of the installation these will be inspected and tested before being concealed.

b. Where cables are run behind 'pinned' ceilings or buried underground, tests must be carried out immediately after the ceiling is fixed and before decorations commence.

c. Inspection and testing of conduits and trunking as previously specified.

d. Testing of MICC cables as previously specified.

When the Supply Authority Board requires a Certificate of Tests as a condition of accepting

an installation or part thereof for final connection to the supply, the Contractor will furnish

such test certificates direct to the Board and forward a copy to the Contract Administrator.

The following sequence of events shall be carried out:

e. Setting the plant to work.

f. Inspection of the plant under operating conditions.

g. Electrical tests on motors and generators and for ensuring the correct phase rotation of the three phase output from standby generation plant with that of the mains.

h. Demonstration to the Engineer of the proper operation of the plant and the control and safety devices under any fault condition.

i. During the execution of the works by the Contractor and on completion (and if considered necessary at the end of the defects liability period) the work shall be inspected by the Contract Administrator for compliance with the Specification.

j. The tests executed in the presence of the Contract Administrator as detailed in the IET Wiring Regulations are as follows:

Continuity of protective conductors including main and supplementary bonding.

Continuity of ring circuit conductors.

Insulation resistance.

Site applied insulation.


Protection by separation of circuits.

Protection by barriers or enclosures provided during erection.

Insulation of non-conducting floors and walls.

Polarity.

Earth loop impedance.

Earth electrode resistance.

• Operation of residual current devices.

k. At the discretion of the Contract Administrator a full load test (1 hour). During this test allow for taking voltage and current readings at the final circuit, sub-main and main intake positions.

l. The Contractor will submit the results of the tests to the Contract Administrator within seven days of the date of testing.

4.37 OPERATING AND MAINTENANCE

In compliance with the Health and Safety at Work Act 1974 the persons in charge of the

building or appointed representatives of the Client shall be instructed in the correct

operation, control and maintenance of the systems and components.

Operating and Maintenance Instructions, purpose written for these particular works in

accordance with the BSRIA Guide BG 1/2007 “Handover operating and Maintenance

Manuals and project feed back” shall be provided. The manuals shall be based on the Class

‘D’ standards and be divided into the following sections:

Introduction/Format of the Manual:

Section 1 How to use the Manual. Section 2 Contractual and legal guides. Section 3 Design intent/parameters. Section 4 Description of systems. Section 5 Schedule of systems. Section 6 Spare parts. Section 7 Spares policy. Section 8 Commissioning data. Section 9 Operation of systems. Section 10 Maintenance and fault finding. Section 11 Modification information. Section 12 Disposal instructions. Section 13 Names and addresses of manufacturers. Section 14 “As Installed” drawings. Section 15 Emergency information. Section 16 Manufacturer’s literature.

Particular attention must be given to detailing the controls strategies, testing durations,

maintenance schedules (every day, every week every month, every three months, every six

months, every year etc.). Manufacturer’s maintenance publications must be included in the

manuals.

Three complete sets of the approved instructions secured inside good quality hard cover ring

binders of adequate size shall be produced and made available at Practical Completion of

the works. Two sets shall be handed to the Client and one set issued to the CDM-C for

inclusion in the Health and Safety File.

The installations will not be accepted by the client until the approved manuals have been

provided.


4.38 HANDOVER

The Contractor shall prior to completion:

a. Supply all test certificates of plant items from manufacturer.

b. Supply all test certificates covering the works during installation and any special tests certified by the Insurance Company.

c. Supply schedule equipment installed.

d. Supply operating and maintenance instructions and drawings for the proper working of the whole installation.

e. Supply adequate information for inclusion in the Building Log Book.

f. Supply of adequate instructions on safety precautions under fault conditions.

g. Supply a list of names, addresses and telephone numbers of all contracting firms and manufacturing firms responsible for the installation or supply of equipment items comprising the Contract Works.

h. Supply spares as indicated and/or makers recommended list of spares.

i. Make sure all plant items clearly show actual manufacturers nameplate giving plant details, reference numbers, duty and date of manufacture.

j. Attend to the general finishing of installation.

k. Agree with Contract Administrator a list of defects and rectify such defects.

l. Supply accessory, plant and equipment keys in duplicate.

m. Supply Health and Safety File for the works in its entirely (where applicable).

PARTICULAR STANDARDS SPECIFICATION

FOR PRE-INSULATED STEEL UNDERGROUND

DISTRICT HEATING DISTRIBUTION PIPELINES

THE MATERIALS AND WORKMANSHIP

DETAILED IN THIS SECTION APPLY EVEN IF

NOT DETAILED IN THE RELEVANT

PARTICULAR SECTION

January 2001 (revised 2007, January 2010, March 2011 and June 2011)

INDEX

ITEM DESCRIPTION PAGE

GENERAL 1

1.0 General 1

1.1 Piping System Design 1

MECHANICAL INSTALLATION

2.0 Pipes 2

2.1 Pre-insulated pipes 2

2.2 Steel Pipes 3

2.3 Foam Insulation 3

2.4 Documentation of Heat Loss 3

2.5 Outer Casing 3

2.6 Receipt, Handling and Storage 3

2.7 Alarm Wires 4

3.0 Joints 4

3.1 Fusion Welded Joints 5

3.2 Tightness Test of Casing 5

3.3 Insulation of Joints 5

4.0 Alarm System 6

4.1 Jointing of Alarm Wires 6

4.2 Instruction Material 6

4.3 References for The Alarm System 6

4.4 Central Surveillance 6

5.0 Installation Techniques 7

5.1 Expansion Movements 7

5.1.1 Sand Layer for Expansion 7

5.1.2 One – Time Compensator 7

6.0 Valve Arrangements 7

6.1 Operating Equipment 8

7.0 Branch System 8

7.1 Hot Tapping 8

8.0 Bends/Directional Changes 8

8.1 Pipes of Small Diameter 8

8.2 Pipes of Large Diameter 8

8.3 Curving of Pipes 9

8.4. Mitred Pipework 9

9.0 Venting 9

10.0 Pits 9

11.0 Testing 9

11.1 Steel Pipework Weld Testing 9

INDEX

ITEM DESCRIPTION PAGE

11.2 Flushing and Filing the Pipework System 9

11.3 Pressure Testing 10

11.4 Repairs 10

12.0 Training 10

13.0 Instruction on Site 10

14.0 Planning Assistance 10

15.0 Quality Assurance 10

15.1 Certificate 11

15.2 Assurance of Joint Quality 11

15.3 Technical Documentation 11

15.4 Operating and Maintenance Manuals 11

15.5 As Installed Drawings 11

16.0 References 11

17.0 Guarantee(s) 12

17.1 Defects Liability Period 12

17.2 General Materials Guarantee 12

17.3 Extended Guarantee 12

CIVIL WORKS

1.0 General 12

2.0 Ground Works Design 13

3.0 Planning of Site Works 13

4.0 Site Investigation 14

5.0 Ground Works Provision for Pipe Movement 15

6.0 Maintenance of Existing Works 15

7.0 Trenches/ Excavations 16

8.0 Access/Installation 16

9.0 Inspection 16

10.0 Sand for Backfilling 17

11.0 Backfilling 17

12.0 Reinstatement of Surfaces 17

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Introduction

1.0 General The district heating pipe system will be a bonded system, in which steel carrier pipe, insulation and outer casing are moulded together to form a solid unit. Thus, the expansion movements of the steel carrier pipe shall be transferred to the outer casing via the foam insulation. The pipe system shall be installed as a system locked/restrained by friction, in which the temperature variations in the district heating pipe system are absorbed either as axial stresses in the steel carrier pipe, by reduced expansion movements, or by a combination of both. All pipework installation must be carried out in strict accordance with the following: a) Pipework manufacturer’s specification. b) Current European and British Standards, e.g. EN 253, EN448, EN488 and EN489. This Standard Specification details Southwark Council’s minimum requirements for any pre-insulated pipework installation.

1.1 Piping System Design

Details of equipment, pipework and the distribution system layout indicated on the layout drawing(s) are approximate. A complete installation capable of performing within the specified design conditions for the duration of the systems design life shall be provided. The system shall be fully in accordance with the recommendations and instructions of the pipe component manufacturer. The distribution of forces and pipe movement for the whole piping system shall be carefully considered and the system installed accordingly. Maximum resultant stresses and movements shall be considered at all critical positions in the proposed piping system. Critical positions shall include anchors, bends, branches and building entries. All loading conditions shall be considered in order to ensure that maximum values of resultant stress and movement have been established. The effect of structural discontinuities and pipeline supports shall be taken account of. Prepare detailed designs for each part of the works in accordance with BS 7572. Issue drawings and calculations for comment by the client/consultant Contract Administrator. Any re-design undertaken during the course of the installation shall be checked, confirmed and re-issued by the designer to all relevant parties, including the client/consultant Contract Administrator for approval before any alterations commence. The Contractor shall set out the Works and be responsible for the accuracy of the same and the positioning of all fittings. The Contractor shall be deemed to have taken full account of the latest drawings, so as to ensure that the requirements of these other services do not conflict or vary the requirements of the setting out drawings. The Contractor, at his own cost, shall amend any errors arising from his own inaccurate setting out unless the Designer shall otherwise direct.

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The Contractor shall be responsible for providing builders’ work information in sufficient time for the progression of any element of Works. Any inaccuracies arising from the inaccurate setting out or late information shall be rectified at the Contractor’s cost. The mechanical services shall be set out and account shall be taken of all other trades and utilities. If during the progress of the work any error shall appear or arise in the positions, levels or dimensions of the said works, the work shall be altered at no extra cost and to the satisfaction of the Architect, the Consultant Building Services Engineer and the client if required to do so. The contractor shall liaise with all other utilities in the design and selection of the new underground pipe routes. In the pursuance of the works, it may be necessary to modify or re-route existing services. The contractor shall be responsible for identifying all existing services located along the proposed pipe route, and shall take into account any modifications or alterations that may be necessary. Any necessary modifications or alterations to existing services are deemed to be included within the tendered sum and are to be carried out at no extra cost and to the satisfaction of the Architect, the consultant Building Services Engineer and the Client.

Mechanical Installation

2.0 Pipes

2.1 Pre-insulated pipes

The prefabricated pipes shall be made of a steel pipe, polyurethane foam insulation with integral copper alarm wires and an outer casing of high-density polyethylene (HDPE). The materials shall be bonded together to form a solid unit in accordance with EN253. The pre-insulated pipework installation must be able to operate at continuous

temperatures of up 140C without suffering any degenerating effect. In order to ensure uniform shear strength, the steel pipe must be grit blasted to min. preparation grade Sa 1 (ISO 8501-1: 1988) immediately before foaming. Heat losses from the pre-insulated pipes shall not exceed the values given in Table 1 below. Soil cover: 500mm Distance between pipe jackets: 150mm

Nominal Bore of Steel Pipe (mm)

Heat Loss in each pipe in W/m at temperature

oC

40 60 80 100

25 4.7 7.6 10.7 13.8

32 5.1 8.3 11.6 15.0

40 5.7 9.4 13.1 16.9

50 6.4 10.5 14.7 18.9

65 7.2 11.8 16.5 21.3

80 6.8 11.1 15.5 20.0

100 8.0 13.2 18.4 23.8

125 9.1 15.0 20.9 27.0

150 8.6 14.0 19.6 25.3

Table 1 – Heat Losses from Pre-Insulated Pipes

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Note:

Where the installation pipework is larger or smaller than the sizes given in Table 1, the supplier/contractor must forward heat loss figures for the pipes (W/m) to the client/consultant Contract Administrator for approval. Where (for whatever reason) it is not possible to install pipework with the above high thermal performance, the client/consultant Contract Administrator may consider pipework of a lower thermal performance (must always comply with EN 253). In all such instances the supplier/contractor must clearly demonstrate and satisfy the client/consultant Contract Administrator that the lowering of standards is unavoidable. All pipework heat losses (W/m) must be forwarded to the client/consultant Contract Administrator for approval prior to the commencement of works.

2.2 Steel pipes

The dimensions of the steel pipes shall be in accordance with ISO 4200/DIN 2458. The pipes shall be delivered as welded pipes in steel quality St. 37.0 according to DIN 1626 or a corresponding standard. Welding factor v = 1.0. The pipes must conform to the technical requirements laid down in DIN 1626, and the quality must be documented in a works certificate according to DIN 50049/ 3.1 B.

2.3 Foam insulation

The moulded polyurethane foam must consist of min. 88% closed cells. The polyurethane foam must be guaranteed to withstand continuous temperatures of

up to 140 C without any detrimental/degenerating effect.

Upon request the supplier shall be able to present documentation of the lifetime of the applied foam insulation in relation to the operating data.

2.4 Documentation of heat loss

Upon request the supplier shall be able to present calculations of the current heat loss for individual pipes as well as for the total system, and for maximum temperatures around the outer casing.

2.5 Outer casing

The outer casing shall consist of a resistant high-density polyethylene material (HDPE) with the following properties

Density: Min. 950 kg/m3

Elongation: Min. 350% Yield stress: Min. 19 N/mm

2

In order to obtain the optimum bond between outer casing and PUR-foam, the inner surface of the outer casing must be subjected to a corona treatment during extrusion.

2.6 Receipt, handling and storage

Upon receipt, all materials are to be inspected for quality; any materials found to be of sub-standard quality will be rejected. Materials must also be checked for the required

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markings and certification, e.g. manufacturers and national standards markings, works certificates, time of production, etc. All pipework, fittings and associated materials are to be stored on site in strict accordance with the pipework manufacturer’s recommendations. Before, during and after installation it must be ensured that the insides of the pipes and components are clean, dry and free from foreign bodies. All free steel pipe ends must be protected from the intrusion of dirt and foreign bodies by suitable means, e.g. plastic caps. If during the installation process a free pipe end is left unsupervised, steel plates are to be welded on to ensure that the pipeline remains clean. Adequately wide straps according to the dimensions in question should be used as lifting tools together with sufficiently wide supports. As a guideline, straps must be at least 100mm wide. Metallic straps, chains, wires etc must not be used. Security of all stored equipment is the sole responsibility of the contractor.

2.7 Alarm wires

The district heating pipe network shall be monitored by an alarm wire circuit in connection with a documented, proven technique.

3.0 Joints

After welding and hydrostatic pressure testing of the steel pipes, the joints shall be sealed with muffs and insulated. The pipework manufacturer must approve the method of jointing and the pipework manufacturer must manufacture all jointing materials.

Under no circumstances shall third party joint assemblies be permitted. The jointing materials shall be delivered wrapped in accordance with the manufacturer’s recommendations/instructions. Packaging and/or protective wraps/covers must not be removed from the assembly components until shortly before joint installation is commenced. The joint shall be easy to inspect by the supervision personnel, as planned visual check points shall be able to show that installation and foaming have been done correctly. The joint shall be power transmitting, and it shall be possible to have the joint pressure tested for tightness before it is insulated. It is essential that sufficient workspace be provided to ensure a quality jointing procedure. The assembly must be executed under dry conditions above ground or in a completely dry excavation. Proper protection may be established by lifting the pipes off the bottom of the excavation and by covering the assembly area with a tent. The muff installation should be planned in such a way that the muffs are jointed, pressure tested and insulated all on the same day.

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Only the following joint type will be acceptable:

3.1 Fusion welded joints.

A joint type is required which can be welded together with the outer casing of the pre-insulated pipe to form an unbreakable unit. The welding shall be done by a tested and approved procedure which can be applied without problems outdoors under all weather conditions. On completion of the welding joint, it shall be possible to document a fault-free welding procedure. After pressure testing the joint, it shall be possible to repair any leaks by a welding process, without having to remove the joint. Once the installation of the joint has been completed, tested and insulated, the filling/testing hole(s) shall be sealed by welding. Polyethylene welders shall posses evidence of valid qualifications which document their ability to perform reproductive welding of the quality specified. Note: Fusion welded joints are required throughout the entire pre-insulated pipe work installation, covering all pipe work diameters unless otherwise approved and confirmed in writing with the client/consultant Contract Administrator. Deviation form the use of fusion welded pipe casing joints will only be considered in exceptional circumstances.

3.2 Tightness test of casing.

Tightness testing of all joints is to be carried out using air or other suitable gas, before the air gap between the steel pipe and casing is insulated.

The test pressure applied will depend on the type of joint used. Testing can normally be done by applying an over-pressure of 0.2 bar to the joint. Tightness is to be checked by use of a suitably sized pressure gauge and suitable fluid indicator. The test fluid must not be detrimental to the casing, joint material or the surroundings. The test period should be for a minimum of 1-minute duration.

3.3 Insulation of joints

The PUR-foam insulation shall completely fill the joint. The foam losses shall be less than 0.1 litres for each joint. Polyurethane foam liquids shall be delivered in sets with measured quantities for each joint size. A distinct indication on the packing of each set must show for which joint size the set is to be used. It shall be possible to mix the two liquid components efficiently in a closed system, so that the entire process of mixing and pouring the liquids into the joints can be done without the fitter running any risk of coming into contact with them. On large projects joints may be foamed by the use of machines. In such cases the quality and quantity of the foam is to be examined by means of trial ‘bag injection’. The client/consultant Contract Administrator may require destructive procedure tests to be carried out on a limited number of finished joints. Finished joints are cut open, and insulation joint and foam are inspected by suitable means.

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Under no circumstances shall pre-fabricated insulating half-shells be permitted.

4.0 Alarm system

The alarm system shall be established on the basis of copper wires moulded into the insulation. The system shall be able to detect the ingress of moisture in the foam insulation by a measurement between copper wire and steel pipe and it shall be able to accurately locate the fault before damage leads to corrosion of the steel pipe. Moreover, the alarm system shall be able to locate a break of the measuring wire and it shall be prepared for central surveillance by a combination of the integral copper wires and other system components. The system shall be of an active type providing continuous surveillance. The components shall include the provision of centrally sited fault locator/surveillance system supplied with an LED display which will continually display (but not be limited to) the following: i. Wire resistance Ω ii. Alarm signal iii. Date/time iv. Error Voltage The alarm system must be capable continually monitoring the entire pre-insulated pipe network. As previously stated, the alarm system offered must be an integral part of the pipe system, as approved by the pipe system manufacturer. Non-approved third party alarm systems are not permitted.

4.1 Jointing of alarm wires

The supplier shall deliver the crimp connectors and tools necessary to ensure a correct jointing of the wires. All wire joints shall be crimped and soldered. For the installation the supplier shall deliver a portable measuring instrument which is to be used for test measurements which ensure that the wires have been installed correctly in accordance with given instructions. The supplier shall deliver a hydroscopic material to be placed around the wires in each joint in order to ensure a rapid and reliable detection of any fault occurred.

4.2 Instruction material

The supplier shall prepare a complete diagram for the wire circuit and position of components. When the installation is taken into operation, a complete instruction manual for fault locating and maintenance shall be placed at the customer's disposal.

4.3 References for the alarm system

Under point 16, references, the supplier shall be able to indicate and describe at least

10 alarm systems which have been in operation for a minimum of 10 years in the UK.

4.4 Central surveillance

The supplier shall be able to deliver equipment, which - on the basis of the integral copper wires - make a central surveillance of the connected units back to a central

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computer possible (incorporating volt free contacts for Building Energy Management Systems monitoring/alarm).

5.0 Installation techniques

The pipe system shall be installed as a system locked/restrained by friction. This can be done by observing the requirements to a firm bond between steel pipe, insulation and outer casing as described under point 1. The temperature variations of the district heating water shall be absorbed either as axial stresses in the steel carrier pipe, by reduced expansion movements or by a combination of both.

5.1 Expansion movements

In the case of expansion movements at bends and branches it is possible to use an increased layer of sand. In certain cases, as described in item 5.1.2 one-time compensators may be used.

5.1.1 Sand layer for expansion

Expansion movements at bends and branches are to be absorbed by providing an extra wide sand layer between the outer casing of the pipes and the trench walls. The supplier shall indicate the thickness of the sand layer.

5.1.2 One-time compensator

These are compensators, which only act during the initial heating of the system. They are usually installed in systems requiring long, straight runs of pipework. The supplier shall confirm size and installed position of each one-time compensator.

6.0 Valve arrangements

Isolation valves shall be delivered as pre-insulated units which can be buried directly in the soil like all other components. Insulation and outer casing material shall fulfil the same quality requirements as described under sections 1 and 2 and which apply to all other components in the system. Isolation valves shall be designed on the basis of a maintenance-free ball valve with an all-welded valve body and a stainless polished valve ball placed in spring-loaded teflon seats. Valve arrangements shall be so designed that a problem free operation is ensured regardless of their position in a pre-stressed pipe system. Isolation valves shall be marked permanently with closed and open position, and it shall be possible to effect replacement of stop and stem seals without having to remove casing and insulation material. Where valves are not buried in the ground (within pits, above ground etc), they are to be of parallel slide construction or similar and approved. All valves must meet current British and European Standards and be fully compatible with the operating parameters of the system.

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6.1 Operating equipment

For the operation of valves in dimensions smaller than 219.1 mm the supplier shall deliver standard T- keys.

For the operation of valves in the dimension 219.1 mm or larger the supplier shall deliver a complete planetary gear arrangement.

7.0 Branch system

The supplier shall indicate system solutions by which in the case of subsequent connections to a main pipe branches can be installed at any point of the pipe run. Cutting of the main pipe run shall be avoided. It shall be possible to install branches at right angles to the main pipe run as well as parallel with it. The supplier shall indicate which branches are to be reinforced. Before their insulation, it must be possible to subject the branch fittings to a pressure test to check their tightness. Whatever branch technique is used, the finished branch shall be of the same quality as the other parts of the system.

7.1 Hot tapping

The supplier shall state principles for installing a branch in a system in operation, observing the requirements specified under point 7.0. This operation is only to be considered following approval from the client/consultant Contract Administrator.

8.0 Bends/directional changes

Bends and curved pipe elements shall be delivered as system solutions which after installation are to the same quality as all other system parts.

Note: Only pre-fabricated bends are to be used on main runs. Bends will take the form of either a plastic coated steel bend fitting on the outer casing, and a weldable elbow on the steel pipe or a manufactured pre-fabricated bend (manufactured by pipework supplier). If bends are made with bend fittings, it must be possible to check their tightness by an air pressure test before they are insulated.

8.1 Pipes of small diameter (up to a max steel pipe diameter of 90mm)

Directional changes in the pipes of small diameter shall, to the extent possible, be effected by curving the pipes on site (using special tools as specified by the supplier).

8.2 Pipes of large diameter (steel pipe diameters in excess of 90mm)

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Directional changes in pipework of large diameter shall, to the extent possible, be effected by using pipes curved in the supplier’s factory according to the indicated curving angle.

8.3 Curving of pipes

For the curving of pipes on site as well as in the factory, techniques and equipment shall be used which ensure that sporadic overloading of the materials used is avoided.

8.4 Mitred pipework

Mitred pipework shall only be allowed in special cases. Depending on the position of the mitre and the pipe dimension, the supplier shall provide the necessary instructions for size and execution. This operation is only to be considered following approval from the client/consultant Contract Administrator.

9.0 Venting

Every effort must be made at the design stage to ensure that the installation of vent components within the underground pipework network is not required. Where the installation of vents cannot be avoided, they must be standardised components manufactured by the pipework supplier. The components Insulation and outer casing material shall fulfil the same quality requirements as described under point 1 and which apply to all other components in the system.

10.0 Pits

Where (for whatever reason) it is necessary to construct underground pits as part of the underground pipework installation, the design specification must be of the highest standard and agreed with the client/consultant Contract Administrator prior to the commencement of works. The proposed pit construction must ensure the prevention of water penetration from any external source.

11.0 Testing

11.1 Steel pipework weld testing

100% of welds to be examined by non-destructive test (radiographic or ultrasonic according to the pipework manufacturer’s specification). All steel pipe welding is to be undertaken by certified coded welders. Certification must be in compliance with current British and European Standards. Original Certificates for individual welders are to be made available to the client/consultant Contract Administrator upon request. Welders may be submitted to a welding test with at least the same acceptance criteria as the criteria for the finished work, with reference to EN 25817.

11.2 Flushing and filling the pipework system

The newly installed pipework system must be fully flushed twice, the flushing water can be from a suitable cold water main supply (contractor to arrange and provide suitable mains water connection). Final filling of the installation must be with de-mineralised water (contractor to provide via tanker/bowser or other suitable means).

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11.3 Pressure testing

Installation pipework to be hydrostatically pressure tested to 1.5 times the systems operating pressure for a period of 24 hours. Following completion of a satisfactory pressure test the site closures will be made in strict accordance with the pipework manufacturer’s specification.

11.4 Repairs

Any repairs required prior to backfilling must be carried out in strict compliance with the pipework manufacturer’s recommendations. All repairs must be completed to the client/consultant Contract Administrator’s satisfaction.

12.0 Training

The supplier shall have training facilities and carry through courses for fitters and supervisors. The training courses shall as a minimum include theoretical training in system function and installation as well as practical training in the installation of joints and alarm components.

13.0 Instruction on site

The contractor/supplier shall ensure that there is a full time resident engineer on site to closely supervise the correct installation of the system. The resident engineer must be experienced and fully trained in all aspects relating to the pipework system being installed. The resident engineer must have previously occupied the same supervisory role on at least 5 projects of similar or larger size. The previous projects must have been using the same pipework supplier’s materials and equipment. The resident engineer shall communicate with the client/consultant Contract Administrator on a daily basis and be available for advice and instruction. The resident engineer may be required to attend meetings at short notice; these meetings may be either in or outside normal working hours. The resident engineer is responsible for the commissioning of the alarm system.

14.0 Planning assistance

The supplier shall make technical assistance available to the client/consultant during the detail planning and the installation phase.

15.0 Quality assurance

The underground pipework system being installed will be expected to have a service life of 30-50 years. This long service life is only obtainable when the installation is performed as high quality work. High quality work can only be evaluated and assured when a system for quality assurance has been implemented for the project. The supplier shall be able to document and demonstrate that all quality activities throughout the entire procedure from customer's request, development/design, purchase, manufacture, and installation to delivery to the customer are carried out under well-organised and controlled conditions.

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As a minimum the supplier shall be able to forward a quality manual or other kind of description of the quality system. The spheres of responsibility and authority concerning quality shall be defined and described in such a manner that the effect of the system and the authority of the quality manager can be judged. The quality system shall be based on the requirements laid down in the international standard for quality systems, the ISO 9001. All on site procedures must be controlled by an approved quality system, to ISO 9002.

15.1 Certificate

Upon request, the supplier shall be able to document the company's quality in a certificate. The certificate shall contain inspection and test results for raw materials, semi-manufactured and finished components for the current delivery.

15.2 Assurance of joint quality

The supplier/contractor shall prepare a quality plan, describing the quality activities carried through to ensure a defensible and reliable installation of joints on site

15.3 Technical documentation

The supplier/consultant shall provide documentation detailing all design data (including worked calculations), materials, procedures, method statements and standards of work appertaining to underground pre-insulated pipework installation. Design data and calculations will be required for all specialised components, e.g. one-time compensators. The submitted documentation must contain but not be limited the following: i. Working/design drawings, including surveyed existing utilities. ii. NDT test report and scheduling of all steel pipework works iii. Fusion weld joint schedules and data, iv. Health and Safety related method statements.

15.4 Operating and maintenance manuals

Upon completion of the works the client shall be forwarded 2 hard copies and 3 electronic copies of detailed, properly prepared O&M manuals. The manuals must be in compliance BSRIA Application Guide 1/87.1.

15.5 As-installed drawings

Upon completion of the works the client shall be forwarded 3 full (hard copy) sets of fully dimensioned as installed drawings. Also 3 copies of all drawings must be provided in electronic form.

16.0 References

Upon request, the supplier must be able to demonstrate their experience in the

installation of pre-insulated district heating pipework on a minimum of 3 UK sites. Such installations must be of a size and proportion to that of the proposed works.

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The contractor shall provide reference’s for each of the minimum installations aforementioned above and each reference shall contain as a minimum the following pieces of information:

1. Client 2. Year of commissioning

3. Dimensions ( of pipework plus length installed pipework in metres ) 4. Alarm system 5. Client contact name / telephone number

All of the installations described shall be furnished with an alarm system as specified under point. 3.

17.0 Guarantee(s)

17.1 Defects liability period and extended warranty

The standard 12 month defects liability period will be applied from the date of practical completion. There will be an additional 4 year installation warranty for all parts and labour which will cover the complete installation including but not limited to the following: Workmanship. All pipework welded joints. All outer pipe case joints. Excavation and reinstatement work. Alarm system (subject to conditions). Valves. (subject to conditions)

17.2 General materials Guarantee

All pipe and associated components, including alarm system, shall be covered by a manufacturers 5-year guarantee.

17.3 Extended Guarantee

Should the conditions of the contract be appropriate, a long-term mutual guarantee

(minimum period of 15 years) between the client and the supplier shall be entered into. The guarantee itself will be covered by a suitable Contract. The pre-insulated underground distribution system will be covered by a long-term service maintenance

contract (minimum period 15 years). This will be serviced by an annual charge (index linked), or by a one-off lump-sum payment.

Civil Works

1.0 General

This section covers the ground engineering works associated with the laying of the piping system. The civil engineering works and associates material specification shall be to the approval of the client/consultant Contract Administrator.

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The approximate routes of the piping system are as Indicated on the tender drawings. The final routes shall be determined by the contractor and approved by the client/consultant Contract Administrator before work commences on site. As far as practicable, routes shall follow the features of the site such as roadways and building lines. Road crossings shall normally be at right angles to the line of the road.

2.0 Ground Works Design

The contractor shall be responsible for the design and execution of all ground engineering work, which is necessary to ensure the suitability, compatibility and correct location within the system of components selected by him to meet the specified performance of the installation. Ground works design shall be based upon good working practice and shall include the following: a) The piping system design requirements of this specification. b) The particular ground and site conditions relating to the site. c) The location of existing services, building structures and other obstructions, and

constraints along the route of the pipework system. d) The expected ground movement. e) A minimum ground cover of 500mm below the base of the road layer or the ground

level of grassed areas. Where this cover cannot be achieved reinforced concrete flags placed above the initial 150mm of backfill sand shall limit the ground pressure loading on the pipeline to 50 kN/m

2.

Trenching and bedding shall be designed with due consideration of ground conditions, loading requirements, construction requirements, pipe strengths and pipe gradient. The trenching design shall accommodate the following surcharge loadings: a) Main Roads - A group of 8 wheels arranged as in BS 5400: Part 2 type HB road

loading, each wheel having a static force of 90 kN with an impact factor of 1.3, all acting simultaneously.

b) Light Roads - A group of 2 wheels spaced 0.9 metres apart, each having a static

force of 70kN, with an impact factor of 1.5, both wheels acting simultaneously. c) Grassed Areas - The same wheel arrangement as for (b) but with a static force of

30kN and an impact factor of 2.0. d) Construction Areas - As per item (a) using the maximum static force associated

with the largest mechanical item of plant to be used on site. Road areas shall include all verges up to 2 metres outside the kerb lines. The design of all anchor blocks shall be based on the loading data derived from the contractor's piping system calculations taking full account of the ground conditions relating to the site.

3.0 Planning of the Site Works

The sequence of the site operations shall be planned so that the work advances steadily and efficiently. Due recognition shall be given to the work programme and proximity of other contractors.

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The contractor shall programme the Works so that they proceed with minimum inconvenience and disruption to the site occupants (and other users). The sequence of operations shall be as follows (where appropriate): a) Site investigations and trial digs. b) Setting out. c) Breaking up of hard surfaces. d) Excavation, trench supports, support of existing services and de-watering of

trenches. e) Preparation of trench bottoms. f) Initial bedding or other support. g) Pipelaying and jointing processes. h) Inspection and preliminary testing of pipe integrity. i) Completion of sand bedding (including side fill and first 150mm layer of bedding). j) Backfilling of trench and withdrawal of trench supports (including laying of warning

tapes). k) Disposal of surplus soil. l) Temporary reinstatement of surfaces. m) Final testing and commissioning of the piping network. n) Permanent reinstatement of surfaces. o) Takeover and defects liability period. The programme of excavation work shall ensure that the opening of trenches, and installation of the piping system, is only carried out over such lengths as can readily be completed in one continuous operation. It shall be organised so that there is sufficient labour, plant and material to keep the complete excavation ahead of pipe laying with the smallest possible length of trench standing open at any one time. Excavation of new sections of pipelines shall not be connected until an adequate supply of pipe and components are available. A reserve of appropriate materials and equipment shall be kept on site for immediate support of unexpected ground conditions. Where work is likely to be suspended for any appreciable length of time, the construction schedule shall be arranged so that lengths of trench are not left open.

4.0 Site Investigation

The contractor will be deemed to have visited the site and to have taken account of the topographical and other features apparent from a visual inspection of proposed piping routes. The contractor shall undertake a computer assisted radar topographical survey of the site, identifying the presence of existing services/utilities plus the presence of any hazards, e.g. old foundations, old cellars etc. The contractor shall check and verify all information supplied to him, prior to commencing detailed design. The contractor shall carry out a site investigation and ground exploration, as necessary to obtain the necessary design information. The contractor shall detail all existing services within his working and as installed drawings. The contractor will at his/her own cost, alter, amend and overcome any pipe routing conflicts or errors which may arise as a failure to identify any buried services/ utilities and/or hazards.

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5.0 Ground Works Provisions for Pipe Movement The contractor shall make the necessary provision to fully account for thermal movement of pipe casings within his design and installation.

Systems using underground voids, culverts, lubrication and non-bonded techniques, for expansion control, shall not be accepted.

Concrete anchor blocks and other associated builders work shall be shuttered and cast to details shown on the approved drawings. Anchors to comply fully with pipework manufacturer’s specification.

6.0 Maintenance of Existing Works

Before commencing any site operations, the contractor shall notify (in writing) the service and utility authorities of the impending installation works and obtain details, and locations, of all installations (whether buried, hidden or visible) existing in the vicinity of the works. Requests by any such third parties to witness any trench opening(s) must be notified to the client/consultant Contract Administrator and strictly adhered to. Unless otherwise approved by the client/consultant Contract Administrator,

excavations within 600mm of existing services shall be by hand digging (NB. This

clearance may be increased to suit the particular requirements of the various

utility providers). All services uncovered, whether expected or not, shall be reported immediately to the client/consultant Contract Administrator; they shall be supported by slings and other suitable means and be adequately protected. Any damage to services, however minor, shall be reported immediately to the client/consultant Contract Administrator; no repairs or replacement shall be carried out without approval from the client/consultant Contract Administrator. A photographic and a written record shall be kept of the condition of any drain, manhole or other existing work which may be uncovered. Any defect evident shall be brought to the attention of the client/consultant Contract Administrator. The contractor shall not use or interfere with the existing service installations without permission of the client/consultant Contract Administrator, or where appropriate, service and utility authorities. The contractor shall take precautions to avoid damage to existing services and draw his operative’s attention to the attendant risks and dangers. If damage to existing installations occurs during works, then: a) The contractor shall immediately notify (in writing) the client/consultant Contract

Administrator and, where applicable, service and utility authorities. Details of the damage and proposed action the contractor will take shall be given.

b) The contractor shall make arrangement for repair to the satisfaction of the

client/consultant Contract Administrator and, where applicable, to the satisfaction of the service and utility authorities.

c) In the case of urgent repairs, the contractor shall accept any arrangement made by

the Client/consultant Contract Administrator. Such arrangement made by the client/consultant Contract Administrator shall not affect the extent of the contractor's liability.

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7.0 Trenches/Excavations

All setting-out, excavations to required invert levels and backfill of trenches for the underground mains to be incorporated in approved ‘working’ and ‘as built’ drawings. All excavations to be in accordance with relevant British Standards, ACOP’s and construction Regulations, including the provision of temporary fencing, scaffolding, bridging, barriers and watching required. The excavations shall be shored up in compliance with Health and Safety regulation requirements. All shoring shall be positioned to ensure that it does not obstruct the installation works. If this is not possible, attendance shall be given to remove and replace shoring as necessary during pipework installation (only to be carried out if safety regulations are not contravened). The excavations shall be graded to falls (to ensure the complete removal of air from the newly installed pipework) and the trench floor compacted (without the introduction of sand). If ground conditions require it, a concrete blind should be laid and graded to provide a firm trench bottom. Excavations shall be set out to the required invert levels. The client/consultant Contract Administrator may require the contractor to prove the set levels via the use of an adequate levelling device, i.e. Dumpy, Thompson, Cowley etc. The Contract Administrator may request the above checks be made at any stage of the works. Adequately dimensioned welding pits (bell holes) to be excavated wherever welding is taking place in the confines of a trench. This welding pit is to ensure the welder has adequate access to make a perfect joint. Excavated spoil is to be taken away from the trench area. If this is not possible/practical, the spoil may be placed on one side of the trench, leaving a minimum of 1 meter between soil and edge of trench. The opposite side of the trench is to be kept clear to allow access for plant and material for the installation of the new pipework. The excavations shall be kept clear of water at all times from the commencement of works until the backfill is completed. Pumps are to be provided where necessary to ensure this requirement is met.

Trenches are to be maintained, i.e. removal of materials due to trench collapse etc. This shall be carried out from commencement of the works until backfill is completed.

8.0 Access/Installation

Access shall be provided along the route of the underground mains installation for distribution of materials and installation plant. When pipes and fittings are transported to the trench site, precautions must be taken to avoid damage. Temporary support can be arranged by means of suitably sized wooden sleepers, sand bags or styrene blocks. The supports must be able to carry the load of the pipes without damage to the pipe casing or insulation

9.0 Inspection

Trenches and newly installed pipework are to be closely inspected immediately prior to the sand backfill to ensure that the pipework’s outer casing is undamaged in any way. A minimum clearance of 150mm is required to be provided around the outer casing of the pipework throughout the entire length of the new pipework installation. Any section found not to comply with this requirement must be rectified before sand backfill can commence. Contractor to advise the client/consultant Contract

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Administrator of date and time of inspection to allow joint inspection to be made if so required. Notification to be in writing and an allowance of 48 hours to be provided prior to inspection date. The inspection of each section of trench shall be witnessed jointly by the installer and client/consultant Contract Administrator and recorded as such for inclusion within future record documentation.

10.0 Sand for backfilling

Upon request the supplier shall give an approval of the chosen sand material.

11.0 Backfilling

Sand backfill should commence immediately following the successful inspection of both the trenches and newly installed pipework. Closures are to be left exposed until a pressure test has been successfully completed. Care should be given to ensure no damage is caused to the trench or installation pipework during the backfill process.

The backfill sand is manually compacted down (to prevent voids occurring) in layers of 100mm, ensuring that a 150mm layer of compacted sand is provided around and above the pipework’s outer casing. Each layer is to be completely compacted before the next layer is laid. The compacted sand layer shall provide a complete support to the pipes around their entire circumference. Normally, manual compaction is achieved by hand and watering. Careful and even compaction is essential. Sand to be placed without any displacement of the underground mains installation. A warning tape shall be placed 250mm above the crown of each pipeline. Warning tapes shall be of polythene not less that 150mm wide and 0.1mm thick. They shall be mauve in colour and bear the continuously repeated legend “DISTRICT HEATING” in block letters not less than 30mm high. The client/consultant Contract Administrator may request paving slabs to be laid immediately above the finished sand level for added warning/protection. The additional protective measures, if required, are to be covered by a provisional sum included in the tender summary. Above the sand surround a backfill with selected material not exceeding 75mm in size, free from rubble, half bricks, sharp objects and building rubbish, shall be placed in 150mm layers. Each layer to be hand tamped and compacted to give a minimum cover of 500mm between the crown of the underground mains and the base of the road layer or the ground level of grassed areas. Where the specified cover cannot be achieved reinforced concrete flags placed above the initial 150mm of backfill sand shall limit the ground pressure loading on the pipeline to 50 kN/m

2.

12.0 Reinstatement of Surfaces Those parts of the site (and any areas outside the site) disturbed by the Works shall be reinstated to equal the conditions existing before the works commenced. The surface of any road or footpath which has been disturbed by the excavation shall be reinstated to the approval of the client/consultant Contract Administrator. Hard surface areas with broken paving slabs shall be reinstated with new paving slabs to match existing adjoining areas. Cultivated areas, top soil and turf shall be permanently reinstated to harmonize with the adjoining surface. Unless otherwise agreed,

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disturbed grassed areas shall be reinstated with a meadow grade turf, equal to or better than the existing turf quality.

specification heating & domestic services · pdf file · 2016-02-122.40...

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