technical specifications-electrical...

of 38, Technical Specs-Electrical, Tender No.10000002-HD-11120, HPCL NCZ

TECHNICAL SPECIFICATIONS-ELECTRICAL SYSTEM 1. SCOPE OF WORK 1.1 GENERAL

The scope of work covered by this specification shall include supply and installation of all electrical equipment and materials including testing and commissioning. Any equipment, device and component of work not specifically mentioned in this specification but considered essential for proper design, and operation shall be included by the tenderer in his offer. The successful tenderer shall carryout the installation as per the arrangement and details shown in the construction drawing, standard and instructions given by the Engineer in charge. Any variation or changes to be carried out of site shall be done with the approval of the Engineer in charge in writing. The scope or work shall include, but not being limited to the supply, storing installation, testing and commissioning of the following: (a) To receive incoming supply from State Electricity board to HPCL

switch board as per specifications and drawing including LT cabling between switch boards.

(b) Motor Control Centre for Pumps / compressors. (c) Miniature Circuit Breaker Distribution Boards for lighting distribution

boards and power distribution boards, miniature breakers and earth leakage circuit breaker.

(d) 1.1 KV grade aluminium/ copper conductor, PVC insulated / FRLS PVC insulated and sheathed armoured / Unarmoured power / control cables and cable termination accessories like glands, lugs, ferrules etc.

(e) Luminaries and Lamps, Ceilings fans, Exhaust fans. (f) Switch socket boxes, junction boxes and draw boxes. (g) Switches sockets and accessories. (h) 1.1KV grade aluminium/copper conductor, PVC insulated / FRLS

PVS insulated multi stranded wires of various colours. ( I ) Wiring materials and accessories. ( j ) Earth electrode stations and earthing conductors.


(k) Building Electrification, Canopy lighting. External lighting, Low level garden lighting, power connections to all facility sign boards, compressors, dispensing pumps, AC, water coolers , Fountains etc.

( l ) Street light poles and accessories. (m) Cable laying in trenches and backfilling for underground cables. (n) Miscellaneous works other than the above as stipulated in

specification and BOQ. (o) Liasoning with Electricity Board / Telephones Department to avail

power supply / Telephone connection unto the meter board / availing incoming power is given as an optional item, which may be required to be executed on behalf of electricity board.

(p) All other installation materials hardware and consumables. (q) All tools, tackles, ladders etc. and the contractor shall provide all

testing and measuring instruments as required for complete commissioning of all equipments.

NOTE: All the inside wiring of the panels/DB shall be carried out by using

suitable copper lugs and crimping the same. All the wiring should be numbered at both ends for easy identification using suitable size ferules.

The design shall include all reasonable precautions and provisions for the safety of operation and maintenance personnel as well as all rules and regulation of petroleum rules, Electricity rules etc has to be adhered to. All equipment to be supplied shall be subject to inspection by HPCL / consultants. Such inspection shall however not relieve the contractor of his obligations under the contract. The Engineer in charge reserves the right to specify electrical materials and equipment of a particular make for the purpose of standardisation and the tenderer shall agree to supply the materials of the make specified, if so required without any extra cost. The contractor shall be responsible for timely delivery of equipment at site, transport to the place of installation, storing, installation, testing and commissioning of all the equipment and the materials that are included in the scope of work. The electrical contractor executing this work shall have a valid license issued by the State Government for carrying out installation work of the voltage class involved under the direct supervision of a person holding a


certificate of competence for the same voltage classes issued and recognized by the State Government. The tenderer shall furnish with this tender the particulars of the licence for carrying out the installation work against this specification. All necessary scaffolding for working at various heights shall be the responsibility of the Contractor. The contractor shall be responsible for compensation in case of any accident to his workmen or others at site. The contractor shall fulfill and bear all statutory charges for their workmen. i.e. tenderer shall indemnify HPCL / consultant of any such charges as compensation. The contractor shall supply all necessary hardware and consumable required for the entire installation. 1.2 ELECTRICITY SUPPLY PARTICULARS:

All equipment and installation covered under the scope of work shall be designed for electricity supply of the following specification. Voltage : 415 V / 240 V 6% No. of phases : 3/1 Type of system : 3 phase, 4 wire Frequency : 50 Hz + 3% Type of neutral earthing : Solidly earthed Short circuit level : Not exceeding 35 KA at 415 V In certain cases the contractor may have to work on HT lines , 11KV, 22 KV etc specially when connection / supply has to be taken from State Electricity Board. All earthing connection should be megger tested and report submitted. It should be ensured that all resistances observed shall be within the specified limits. 1.3 DRAWING: The drawings enclosed with these specifications are only for the guidance of the tenderer. The exact routing of conduits, cables and wires and the exact location of the equipment shall be as per construction drawings or as decided at site by the Engineering charge. Any field corrections shall be shown in five (5) copies of each drawing and such as built drawings shall be handed over to the HPCL by the contractor after completion of the installation.


The drawings and other documents to be submitted by the tenderer shall be in the English language and all the dimensions, weights and quantities shall be the metric units. The contractor shall submit for the approval of the HPCL / consultant, drawing of switch boards / tailor made equipment etc., as required in four (4) sets before commencing the manufacture and or/ supply. The contractor shall submit four sets (4) of as built certified drawings after completion of installation /fabrication/commissioning. 1.4 LOCAL CONDITIONS: The tenderer shall visit the site, ascertain the local conditions, entry, traffic restriction, and obstructions if any and also site conditions. Whether the tenderer visits the site or not, he is deemed to have visited the site and ascertained all the site conditions. The tenderer shall allow in his tender for an extra likely to be incurred due to site conditions. No claim will be allowed on this account under any circumstances. 1.5 STANDARDS: The equipment and the installation work shall generally conform to the requirements of the Indian Electricity Rules with its latest amendments and all relevant standards and code of practice of the Bureau of India Standards. However, the decision of site engineer shall be final with respect to requirements. 1.6 SAFETY: The tenderer shall include and take adequate precaution as per the Indian Standard codes to ensure safety for personnel and prevention of accidents at site. The tenderers shall be responsible for compensation to their workmen /others due to accidents, if any. 1.7 STATUTORY REQUIREMENTS: The contractor shall obtain the approval of the State Electricity Board and Electrical Inspectorate and carryout changes as called for by the Electrical Inspector at no extra cost to HPCL. He shall also obtain the drawing approvals and final safety certificate from state electricity board.


Only the statutory fees payables to Electricity authority shall be reimbursed by the owner on production of original valid vouchers. 1.8 INSPECTION: All the materials to be supplied shall be subject to inspection by HPCL / consultant. Such inspection shall not however relieve the contractor of this obligation under the contract. Samples of all items, materials, hardware, etc., to be used on the work shall be got approved by the Engineer-in-charge / consultant in advance. The brands / makes and grades of items / materials shall be as directed by HPCL / consultant. 1.9 TIME SCHEDULE: The tenderer shall be responsible for timely procurement and delivery of the items, off-loading at site, safekeeping at site, transport to the place of installation, installation, testing and commissioning of all the material that are included in his scope of work. Work shall be progressed and completed as per schedule mutually agreed upon. 1.10 CO-OPERATION: The contractor shall coordinate his work with those of the other agencies of the site and shall avoid any interference and interruption with the progress of the work of the other agencies. The contractor shall be required to carryout the installation side by side with other agencies as may be required by the other contractor from time to time. 1.11 QUANTITIES: The Quantities indicated in the bill of quantities are for the guidance of the tenderer. The contractor shall supply the items based on the requirements as per Construction drawings only. 2. TECHNICAL SPECIFICATION FOR LOW VOLTAGE (415) SWITCH GEAR /

BOARD GENERAL 2.1 GENERAL: This specification covers the Design. Manufacture, Fabrication, Testing at factory and supply, installation, testing and commissioning of 415 V Switch gear incorporating MCCBs /Fuse Switches / Contactors / relays etc.


This switch board and the mounted equipment shall comply with the latest edition of the following Indian Standards. IS : 13947 Specifications for Low-Voltage Switchgear and Controlgear Part 1 to 5 IS : 13703 Low-voltage Fuses for Voltages not Exceeding 1000 V AC or Part 1 to 4 1500 V DC IS : 2705 Current Transformers. Parts I, II, III IS : 3156 Voltage Transformers IS : 1248 Electrical Indicating Instruments IS :5578 Guide for Marking of Insulated Conductors IS:11353 Guide for Uniform System of Marking and Identification of

Conductors and Apparatus Terminals IS : 5 Colours for Ready Mixed Paints and Enamels IS : 8623 Specification for Low-Voltage Switchgear and Controlgear Part 1 to 3 Assemblies 2.2 GENERAL REQUIREMENTS: 2.2.1 FABRICATION AND GENERAL DETAILS: Switchgear shall be indoor, floor mounting, free standing type enclosed in sheet steel cubicles and shall be dust, weather and vermin proof. Enclosures shall between all adjacent units and underneath all covers to render the joints effectively dust proof. Steel sheets shall not be less than 2.00 mm (14 SWG) in thickness Switch gear should be of single front type design. Switch gear shall be extendible at both ends by the addition of vertical sections. Ends of the bus bars shall be suitably drilled for this purpose. The switch board shall be totally enclosed, dust, weather and vermin proof. If necessary, openings for natural ventilation shall be provided. Gaskets of durable materials shall be provided for doors and other openings. Switch boards specified for outdoor installation shall be housed


in outdoor type kiosks to make it weatherproof. The switchboards shall be suitable for the ambient and site conditions specified. Suitable hooks shall be provided for lifting the boards. These hooks when removed shall not leave any openings in the boards. Access from the back shall be limited to bus bars and cables only for 415 V main switch board and DG panels. For all other panels, all equipments shall be mounted on the front side and shall be accessible from the front side through hinged doors. Switches; ammeters, voltmeters and lamps etc. shall preferably be mounted on fixed portions. Individual switch fuse units, MCCBs, bus bar and cable entrance alleys shall be housed in separate enclosed compartments separated from each other by metallic or any other fire resistant insulating material barriers. Barriers and automatic safety buffers shall be provided such that bus bars and other live parts are inaccessible even with breakers completely drawn out. Opening of bus bar chambers shall be possible with special tools only. 2.2.2 PAINTING: All metal surfaces shall be thoroughly cleaned and degreased to remove mill scale, rust, grease and dirt. Fabricated structures shall be pickled and then cleaned to remove any trace of acid. The under surface shall be prepared by applying a coat of red oxide primer or yellow zinc phosphate primer. The under surface shall be made free from all imperfections before undertaking the finishing cost. After preparation of the under surface the switch board shall be painted by powder coating (25 microns) method as final paint. Colour shade of final paint shall be approved by HPCL before final painting is started. The finished panels shall be dried in stove ovens / Heat ovens in dust free atmosphere. Panel finish shall be free from imperfections like pinholes, orange peels, runoff paint etc. All unpainted steel parts shall be cadmium plated or suitably treated to prevent rust corrosion. If these parts are moving elements then they shall be greased. Suitable lifting lugs shall be provided for switchboard. These lifting lugs shall not leave any opening when removed.


2.3 SWITCH BOARD COMPONENTS: 2.3.1 INSTRUMENT TRANSFORMERS: Current transformer shall generally conform to IS:2705. They shall be mounted on the stationary part. The CT ratio and ratings shall be as indicated on the single line diagrams. For general guidance, the vendor shall note that the protective current transformers shall have an accuracy class 5P and an accuracy limit factor greater than 10 Low reactance CTs shall be used for protection. Current transformers for instruments shall have an accuracy class 1.0 and accuracy limit factor less than 5.0. The current transformer shall be capable of withstanding the peak momentary short circuit current for 1.0 second. The neutral side of the current transformers shall normally be earthed through a link. Wherever provided, the voltage transformer shall generally conform to IS :3156. The voltage transformer shall be provided with primary fuses. Preferably miniature circuit breakers with auxiliary contacts shall be provided on the secondary side. The voltage transformers shall have an accuracy class 3.0 from 50% to 110% of normal voltage and class 1.0 from 80% to 120% of normal voltage with burdens varying from 25% to 100 % of the rated value at 0.8 PF lagging. The primary of the voltage transformers shall be rated for 415 volts and the secondary for 110 volts. Unless otherwise stated, 2 single phase V-connected CTs shall be used. 2.4 MEASURING INSTRUMENTS: 2.4.1 AMMETERS: Ammeters shall be moving iron or moving coil type. The moving part assembly shall be with jewel bearing. The jewel bearing shall be mounted on a spring to prevent damage to pivot due to vibrations and shocks. The ammeters shall be manufactured and calibrated as per the latest edition of IS: 1248. The ammeters shall be of instrument transformer operated and shall be suitable for 5A secondary of instrument transformer. The scales shall be calibrated to indicate primary current unless otherwise specified. The ammeters shall be capable of carrying sustained overloads during fault conditions without damage or loss of accuracy.


2.4.2 VOLTMETERS: Voltmeters shall be of moving iron or moving coil type. The range for 415 V, 3 phase voltmeters shall be 0 to 500V. Suitable Selector switch shall be provided for each voltmeter to read voltage between any two lines of the system. The voltmeter shall be provided with protection fuse of suitable capacity. 2.4.3 SWITCH AND FUSE UNITS: The load break switches shall be heavy duty air break type and shall have quick make / break manual operating mechanism. The operating handle shall be mounted in the door of the compartment having the isolator. It shall be possible to padlock the switches in the ON & OFF position. Door interlock shall be provided so that it should not be possible to open the door with the switch in the closed position. Normally it shall not be possible to close the switches when the door is open, but for testing purposes it shall be possible to defeat this interlock. Switches shall be able to carry full load current continuously without overheating. Barriers shall be provided to prevent inter-phase arcing. The live terminals shall be shrouded to avoid accidental contact. Motor feeder switches shall be adequately rated for motor duty Fuses shall be HRC cartridge link types. Any other type of fuses will not be acceptable. The fuses shall be non-deteriorating type and shall have an operation indicator, which will be visible without removal of fuses form service. Fuses shall be pressure fitted type and shall have ribs on the contact blades to ensure good line contact. It must be possible to handle fuses during off-load conditions although full voltage may be available on the terminals. Fuse-pullers shall be provided. 2.5 MOULDED CASE CIRCUIT BREAKERS (MCCBs): 2.5.1 General: MCCBs shall be four-pole, triple pole or double pole, independent manual closing air break type. They shall be totally enclosed in a moulded casing formed from an insulating material. The construction of the casing shall be capable of withstanding the appropriate rated short circuit current and reasonably rough use without fracture or distortion. The moulded casing shall have protection not less than IP 56.


MCCBs shall comply with and be type tested to IEC 157-1, 157-1A, 157-1B. All MCCBs to be used for serving pump motors, fan motors, AC, Compressors, Pumps and other motor equipment shall be of motor type and shall be capable of handling the starting currents. All MCCBs shall be completed with dust-proof metal enclosures with all the live terminals totally enclosed. Operation Characteristic: MCCBs shall have a thermal-magnetic tripping mechanism on adjustable, stable, inverse time-current characteristic. The operating characteristic shall be such that: The time delay on overload tripping shall be inversely proportional to the over currents unto a threshold value of approximately 7 times the rated current. There shall be no intentional time-delay on over current tripping due to short-circuit, heavy over currents exceeding the threshold value. The overload trip setting can be adjusted on site from 60% to 100% of breaker rated current in10% steps. Performance Characteristic: MCCBs shall be certified, in accordance with IEC Standards and shall have the following performance characteristics: Rated short circuit breaking capacity not less than 25 KA for lateral sub-main installation or the prospective fault current at the points of installation whichever is greater. Short circuit current withstanding duration shall not be less than 1 second. 2.5.2 Shunt Trip Release: This shall operate correctly at all values of supply voltage between 70% and 120% of the nominal supply voltage under all operating conditions of the MCCB. MCCBs incorporating shunt release shall be provided with block terminals and shunt release lead cables. All the MCCB should have front drive kits.


2.5.3 CONTROL SWITCHES: All control switches shall be rotary, back connected type, having a cam operated contact mechanism. Preferably phosphor bronze contacts shall be used on the control switches. They shall have pistol grip handles. Number of ways, locking system etc. shall be as stated on these switches. Ammeter selector switches shall generally have 4 positions for reading 3 phase currents and the neutral current. The voltmeter selector switches also to have 4 positions. Three shall be used to measure phase to phase voltage and fourth shall be OFF position. Remote / Trip / Off selector for the motor feeders shall be lockable in Off position. 2.5.4 PUSH BUTTONS: Push button colours shall be as follows: Stop / Open / emergency - Red Start / Close - Green 2.5.5 INDICATING LAMPS: Indicating lamps shall be provided with translucent covers to diffuse light, with series resistors. 2.5.6 PROTECTIVE RELAYS: Wherever used, all protective relays shall be back connected, draw out type, suitable for flush mounting and fitted with dust tight covers. Alternatively, plug in type of relays shall also be acceptable. The relay cases shall have provision for insulation of test plug at the front for testing and calibration using an external power supply without disconnecting the permanent wiring. It shall be possible to short the CTs through the test plugs. 2.5.7 AUXIULIARY RELAYS / CONTACTORS: Auxiliary relays / contactor shall generally be used for interlocking and multiplying contacts, Auxiliary contacts shall be capable of carrying the maximum estimated current. In any case, their rating must not be less than 5A for 240 V AC at a power factor between0.3 to 0.1 and 1.5 A for 24


V DC (Inductive load). Vendors shall note that lower voltage contactors with a series resistance will not be acceptable for 220 V DC control supply. 2.5.8 TRIPPING RELAYS: All tripping relays shall be lockout with hand reset contacts and shall be suitable to operate off the specified DC voltage. These relays shall have coil-cut-off contacts and shall be provided with hand reset operation indicators. Tripping relays will be acceptable in non-draw out cases. The number of contacts shall be as shown in the schematic drawings. 2.5.9 INSPECTION & TESTING: The panel shall be completely assembled, wired and tested as per IS-8623-1993 at the factory in the presence of HPCLs engineer or his authorized representative. The test shall include wiring, continuity tests, insulation resistances test, high voltage tests (2.5 KV AC for 1 min.) and functional tests to ensure operation of control scheme and individual equipment. All cost regarding testing will be borne by contractor. Manufacturers test certificates in respect of all meters, switchgears, contactors etc. prior to inspection of Panels shall be produced to HPCLs engineer /representative at vendors works. 2.5.10 DRAWING & INSTRUCTION MANUALS: The contractor shall submit the following documents: General arrangement drawings of panels (cudec switch board) showing the various constructional features etc. Single line diagram. Technical leaflets for MCCBs, fuse switches, lamps meters etc. Foundation plan including weight. Type test reports as per IS:8623 1993. Before taking up the job, the contractor shall submit the following documents in for approval. General arrangement drawing of Panels showing various views and foundation drawings.


The enclosures of the ELCB shall be moulded from high quality insulating materials, which shall be fire retardant, anti-tracking, non-hygroscopic, impact resistant and shall withstand high temperature. 2.5.11 GROUNDING: The DBs shall be provided with two nos. brass earthing stud terminals with suitable nuts, washers etc. for connection of earth bus outside the DB. 2.5.12 PAINTING: The steel surface shall be chemically cleaned to remove scale etc. rinsed dry and shall be finished with Epoxy paint. The shade shall be as advised by ENGINEER IN CHARGE. 2.5.13 TESTING & INSPECITON: All routine and acceptance tests as per the relevant IS shall be carried out ii presence of HPCLs engineer or his representative. 2.5.14 PACKING AND TRANSPORT: The switch board shall be shipped to site packed in wooden crates. They shall be wrapped in polyethylene sheet before being placed in crates to prevent damage to the finish. Crates shall have skid bottoms for handling. All the equipment covered under this specification shall be packed properly in order to avoid damages during transit and during storage at site. 2.5.15 GUARANTEE: The switch board shall be guaranteed for trouble free operation for a period of 12 months from the date of commissioning or 18 months from the date of arrival at site whichever is earlier. Any defects discovered during this period shall be rectified free of charge 2.5.16 DRAWING & INSTRUCTION MANUALS: After completion of job, the contractor shall submit the following documents:


- General arrangements drawings of DBs showing the various constructional features etc. - Single line diagram. - Technical leaflets for MCB, ELCB etc. - Type test reports as per IS. - Arrangement of compartments. - Complete technical particulars of all equipments. - Commissioning and maintenance instruction for all equipments. - Set of re-producible for all the above drawings. Before manufacturer of the DBs, the contractor shall have to take the approval for the design and drawings. Any manufacturing done prior to approval of drawing shall be rectified in accordance with the approved drawings by the supplier at his own cost and the equipment shall be supplied within the stipulated period. 3.0 TECHNINCAL SPECIFICATION FOR POWER & LIGHTING DISTRIBUTION BOARDS 3.1 GENERAL: This specification covers the design, manufacture, assembly, testing, supply, installation and commissioning of all power and lighting distribution boards complete with all accessories for efficient and trouble-free operation. The distribution boards shall be fabricated out of 1.6 mm thick sheet (CRCA) and shall be totally enclosed, dust and vermin proof, dead front, with hinged door type ,of bolted / welded construction suitable for wall mounting. Each DB shall have individual hinged / bolted gasket doors with a suitable tacking device and shall be suitable for dusty atmospheric condition. 3 mm thick removable gland plates shall be provided in the top and bottom of the distribution boards for cable entry. Protective insulated cover plate shall be provided inside the panel to shroud the live parts. Only the operating knobs of the miniature circuit breakers/ELCB/RLCB shall be projecting outside the cover plate. The incoming/outgoing ELCB/MCB terminals shall be suitably shrouded to avoid accidental contact. Each phase or way shall also be suitably shrouded with bakelite hylam plates.


The incoming and outgoing terminals shall be suitable for terminating cables as per the specific requirements. 3.2 BUSBARS: The busbars shall be an insulated and made of high conductivity, electrical grade COPPER liberally sized with safely factor for the required rating (both short circuit and continuous current). The busbar shall be sized for the full rating of the incomer. The neutral busbar shall have adequate number of terminals for all outgoing single phase circuits. A copper earth bus of size. 25x3 mm shall be provided in each DB for earthing of the power/ lighting circuit and earthing of DB. The neutral busbars shall be sized equal to the phase busbar. 3.3 MINIATURE CIRCUIT BREAKERS: The Miniature Circuit Breakers (MCBs) shall be heat resistant, moulded type design, manufactured and tested as per IS: 8828. The MCBs shall have inverse-time tripping characteristic against over loads and instantaneous trip against short circuit. The MCBs shall be clip on type to the DIN Channel. The ON and OFF positions shall be clearly marked. The MCBs shall be suitable for operating in ambient temperature without deterioration. The incoming and outgoing of the MCBs shall be accessible only after opening the front door of the DB. The MCBs shall be suitable for 415 V, 3 pole and 2 pole. MCB knobs shall be trucked with adequately strengthened tandem pin. 3.4 EARTH LEAKAGE CIRCUIT BREAKERS: Incoming of the lighting and power DB shall be provided with current operated Earth leakage circuit breakers with a sensitivity of 30mA or as specified in the drawings. The ELCB shall have trip free mechanism and shall operate even on neutral failure. The ELCB shall be provided with a test Button to simulate leakage and to test the ELCB. The ELCB shall operate and switch off the circuit within 30 milli seconds in case of a fault.


4.0 TECHNICAL SPECIFICATIONS FOR MEDIUM AND HIGH VOLTAGE CABLES AND ACCESSORIES

4.1 GENERAL: This specification covers the requirement for design, manufacture and supply of PVC, FRLS cables for medium and High voltage systems and cable joining / terminating accessories for high voltage / low voltage systems. The cables shall comply with the latest edition of the following standards: IS : 1554 (PART I) PVC insulated (heavy duly) electric cables

working voltage upto and including 1100 V. IS : 7098 (PART I & II) Cross-linked polyethylene insulated PVC

sheathed cables for working voltage from 1.1 KV upto and including 33 KV

IS : 8130 Conductor for insulated electric cables and

flexible cords. IS: 5831 PVC insulation and sheath of electric cables IS : 3975 Mild steel wires, stripes and tapes for armouring of

cables. IS : 2633 Methods of testing weight, thickness and

uniformity of coating on hot dipped galvanized articles.

IS : 209 Specification of zinc. IS : 3961 (PART II) Recommended current ratings for PVC insulated

and PVC sheathed heavy duty cables. IS:10418 Wooden drums for electric cables. IEC:502 Extruded solid dielectric insulated power cables

for rated voltages from 1KV and 30 KV. IEC:540 & 540A Test methods for insulation and sheaths of

electric cables and cords.


IS:10462 Fictitious calculation method for determination of dimensions of protective coverings of elastomeric and thermoplastic insulated cables.

IS:10810 (PART-58) Oxygen Index test. 4.2 GENERAL CONSTRUCTION: The cables shall be suitable for laying in trays, trenches, ducts and conduits and for underground buried installation with uncontrolled backfill and possibility of flooding by water and chemicals. Outer sheath of all PVC and XLPE cables shall be black in colour and the minimum value of oxygen index shall be 29 + 2o c. In addition, suitable chemicals shall be added into the PVC compound of the outer sheath to protect the cable against rodent and termite attack. Sequential marking of the length of the cable in meters shall be provided on the outer sheath at every one metre. The embossing shall be legible and indelible. The overall diameter of the cables shall be strictly as per the values declared in the technical information furnished before taking up the job subject to a maximum tolerance of + 2 mm. PVC/Rubber end caps shall be supplied free of cost for each drum. In addition, ends of the cables shall be property sealed with caps to avoid ingress of water during transportation and storage. 4.3 SPECIFICATION FOR PVC CABLES All power/ control cables for use on medium voltage systems shall be heavy duty type. 1100 V insulated, inner-sheathed, armoured and overall PVC sheathed as detailed below. The conductors shall be stranded for both aluminium and copper cables. Conductors of nominal area less than 25 sq. mm shall be circular only. Conductors of nominal area 25 sq. mm and above may be circular or shaped. Cables with reduced neutral conductor shall have sizes as per Tables. 1 of IS 1554 (Part-I).


The core insulation shall be with PVC compound applied over the conductor by extrusion and shall conform to the requirements of type A compound as per IS: 5831. The thickness of insulation and the tolerance on thickness of insulation shall as per table 2 of IS: 1554 Part-I. Control cables having 6 cores and above shall be identified with prominent and indelible Arabic numerals on the outer surface of the insulation. Colour of the numbers shall contrast with the colour of insulation with a spacing of maximum 50 mm between two consecutive numbers. Colour coding for cables unto 5 cores shall be as per Indian Standard. The inner sheath shall be applied over the laid-up cores by extrusion and shall be of PVC conforming to the requirements of TYPE ST-1 PVC compound as per IS: 5831. The minimum thickness of inner sheath shall be as per Table 4 of IS: 1554-Part-I. Armouring for multi-cores cables shall be by single round galvanized steel wires where the calculated diameter below armouring does not exceed 13 mm and by galvanized steel strips where this dimension is greater than 13 mm. Requirement and methods of tests for armour material and uniformity of galvanization shall be as per IS:3975 and IS:2633. The dimensions of armour shall be as per table 5 of IS-1554 (Part-I). Armoring for single core cable shall be with H4 grade hard drawn aluminium round wire of 2.5 sq. mm diameter. The outer sheath for the cables shall be applied by extrusion and shall be of PVC compound conforming to the requirements of type ST-1 compound as per IS: 5831. The minimum thickness of outer sheath shall be as per column-3 for both armoured and unarmoured cables. 4.4 SPECIFICATION FOR XLPE CABLES The conductor shall be stranded and compacted circular for all cables. All cables rated 1.1/ 3.8/ 6.6 KV and above shall be provided with both conductor screening and insulation screening. The conductors shall be provided with non-metallic extruded semi conducting shielding. The core insulation shall be with cross-linked polyethylene insulating compound applied by extrusion. It shall be free from voids and shall withstand all mechanical and thermal stresses under steady state and transient operating conditions. It shall conform to the properties given in Table-I of IS:7098 (Part-II).


The insulating shielding shall consist of non-metallic extruded semi-conducting compound in combination, with a non-magnetic screening of copper screen ,it shall be capable of carrying the insulation shielding ,it shall consist of non-metallic extruded semi-conducting compound in combination with a non-single ,line to ground fault current. The conducter screen, XLPE insulation and insulation screen shall be extruded in one operation by Triple Extrusion process to ensure perfect bonding between the layers. The core identification shall be by coloured strips or by printed numerals. The inner sheath shall be applied over the laid up cores by extrusion and shall conform to the requirements of type ST-2 compound of IS:5831. The extruded inner sheath shall be of uniform thickness. For multicore cables, the armouring shall be by galvanized steel strips. If armouring is specified for single core cables in the data sheet, the same shall be with H grade hard drawn aluminium round wire of 2.5 sq.mm diameter. The outer sheath of the cables shall be applied by extrusion after the armouring and shall be of PVC compound conforming to the requirements of Type of IS: 5831. The thickness of outer sheath shall be as per amendment No. 1 to Table 5 of IS: 7098 part 2. (Column 3 & 5 for both armoured and un-armoured cables). The dimensions of the insulation, inner sheath and armour materials shall be governed by values given in Tables 2,3, and 4 (Method b) of IS: 7098 Part-II. 4.5 SPECIFICATION FOR CABLE ACCESSORIES The termination and straight through jointing kits for use on the systems shall be suitable for the type of cables offered as per specification. The accessories shall be supplied in kit form. Each component of the kit shall have the manufactures mark of origin. The kit shall include all stress grading, insulating and sealing materials apart from conductor fittings and consumable items. An installation instructions sheet shall also be included in each kit. The contents of the accessories kit including all consumables shall be suitable for storage without deterioration at a temperature of 45oC with self life extending to more than 5 years.


TERMINATING KITS: The terminating kits shall be suitable for termination of the cables to an indoor switchgear or to a weatherproof transformer/motor. For outdoor terminals, weather shields/sealing ends and any other accessories required shall also form part of the kit. The terminating kits shall be one of the makes/types mentioned in the preferred makes. JOINTING KITS: The straight through jointing kits shall be suitable for installation on overhead trays, concrete lined trenches, ducts and for underground burial with uncontrolled backfill and possibility of flooding by water and chemicals. These shall have protection against rodent and termite attack. The cables shall be tested and examined at the contractors works both before and after manufacture. The contractor shall furnish all necessary information concerning the supply to consultant/owners works for the purpose of inspecting the process of manufacturer in all its stages and ENGINEER-IN-CHARGE will have the power to reject any material which appears to him to be at unsuitable description or of unsatisfactory quality. 4.6 PVC & XLPE CABLES: After completion of manufacture of cables and prior to dispatch the cables shall be subject to special tests as detailed below. Consultant/owner reserves the right to witness all tests with sufficient advance notice from vendor. The test reports for all cables shall be got approved from the Engineer before dispatch of the cables. All routine tests, acceptance tests and type tests shall be carried out on cables as listed in IS:1554 Part-I. The inner and outer sheath of XLPE cables shall be subjected to all the tests applicable for PVC cables. The test requirements for insulation and sheath of PVC cables shall be as per latest revision of IS:5831. Following are the special tests to be performed on the cables and test results shall be submitted to HPCL if directed. Accelerated water absorption test for insulation as per NEMA-WC-5. (For PVC insulated cables) and as per NEMA WC-7 (for XLPE insulated cables). Dielectric Retention Test: The dielectric strength of the cable insulation tested in accordance with NEMA WC-5 at 75 + 1o shall not be less than 50% of the original dielectric strength. (For PVC insulated cables).


Oxygen Index Test: The test shall be carried out as per ASTMD 2863 or applicable Indian Standard specification. Test for rodent and termite repulsion property. The vendors shall furnish the test details for analyse the property by chemical method. 4.7 CABLE ACCESSORIES: Type tests should have been carried out to prove the general qualities and design of given type of termination/ jointing system. The type tests shall include the following tests conforming to VDE 0278/IS specification. The type test certificates shall submitted if directed by ENGINEER-IN- CHARGE.

(a) Rated withstand AC voltage test. (b) Partial discharge test (c) Rated withstand surge voltage test (d) Continuous AC voltage test with cyclic current load (Number of

heating cycles-3) (e) Partial discharge test (f) Continuous AC voltage test with cyclic current load (Number of

heating cycles-60) (g) Thermal short circuit test (h) Continuous AC voltage test with cyclic current load ( I ) Rated withstand surge voltage test ( j ) D.C. voltage test (k) Test under the influence of moisture ( l ) Dynamic short circuit test

4.8 PACKING AND MARKING: Cables shall be dispatched in non-returnable wooden/steel/plastic drums of suitable barrel diameter, securely battened, with the take-off end fully protected against mechanical damage. The wood used for construction of the drum shall be property seasoned, sound and free parts used shall be treated with a suitable rust preventive finish or coating to avoid rusting during transit or storage. On the flange of the drum necessary information such as project title, manufacturers name, type size, voltage, drum no., cable code, BIS certification direction of rotation of the drum etc shall be provided


Cables shall be supplied in drum lengths as follows: Medium voltage power cables unto and including 6 sqmm- 1000M. Medium voltage power cables from 10 sqmm upto and including 300 sq.mm- 500 M. Control cables unto and including 27 cores 1000M. A tolerance of plus or minus 5% shall be permissible for each drum. However, overall tolerance on each size of cable shall be limited to + 2%. 5.0 TECHNICAL SPECIFICATION FOR LIGHT FITTINGS AND ACCESSORIES 5.1 GENERAL: This specification covers the design, manufacture, testing, inspection and delivery at site and installation of lighting fittings and their associated accessories and commissioning the same. The light fittings and their associated accessories such as lamps/tubes, reflector housings, ballasts etc. shall comply with the latest applicable standards. All luminaries, lamps and accessories shall be of the same make for the particular site as directed by Engineer-In-Charge. 5.2 GENERAL REQUIREMENTS: Fittings shall be designed for continuous trouble-free operation under hot humid atmospheric conditions, at an ambient of 50o C, without reduction in lamp life or without deterioration of materials and internal wiring. Outdoor fittings shall be weather proof and rain proof type. The fittings shall be designed so as to facilitate easy maintenance, including cleaning, replacement of lamps/starters etc. Connectors between different components shall be made in such a way that they will not work loose by vibrations. The fittings shall be supplied complete with lamps.


The fittings and accessories shall be designed to have low temperature rise, the temperature above the ambient temperature shall be as indicated in the relevant standards. All mercury vapour and metal halide fittings she be complete with accessories like lamps, ballast, power factor improvement capacitors, starter/igniter wherever applicable, etc. Outdoor type fittings shall be provided with outdoor type control gear box the fittings shall be power factor corrected to 0.95 logging (maximum). Each fitting shall have a terminal block suitable for loop-in, loop-out and on-off connection. The internal wiring shall be complete by the contractor by means of stressed copper wire and terminated on the terminal block. All hardware used in the luminaries shall be cadmium plated. 5.3 EARTHING Each light fitting shall be provided with an earthing terminal suitable for connection to the earthing conductor. All metal of enclosed parts of the housing shall be bonded to the earthing terminal so as to ensure satisfactory earth continuity throughout the fixture. 5.4 PAINTING All surfaces in the fittings shall be thorough cleaned and degreased. The fitting shall be free from scale, rust, sharp edges and burns. The housing shall be stove-enameled/ epoxy stove-enameled/ vitrous enameled /oxidised as indicated under various types of fitting. The finishing of the fitting shall such that no bright /dark spots are produced either by direct light or by reflection. 5.5 LIGHT 5.5.1 HPSV/HPMV/ MH FLOOD LIGHT LUMINAIRE: Flood light fixture suitable for HPSV/ HPMV/ MH lamps consists of cast aluminium alloy housing with heat dissipating fins. Heat resistant and toughened glass in front is held by a weatherproof gasket and aluminium


frame assembly. It shall have anodized aluminium reflector. Re lamping facility shall be made simple without disturbing the previously set aiming. It shall be provided with galvanized MS mounting bracket which will have facility to fix the fixture in any position. It shall be provided with the protractor angle adjustment. 5.5.2 HPMV/ MH HIGH/ MID/ LOW BAY LUMINAIRE: High/ MID/ LOW bay fixture suitable for HPSV/ HPMV/ MH lamps consists of cast aluminium housing, stove enameled grey outside and white within , an anodized aluminium reflectors and highly transparent clear acrylic sheet cover with hinge and toggle fastening, neoprene gaskets and integrated prewired ballasts etc. 5.5.3 POST TOP LANTERN: The luminaires shall have die cast aluminium spigot complete with integral copper wound control gear, PF correction capacitor mounted in canopy, lamp holder and suitable rated lamps. The diffuser/ cover shall be opal acrylic HDP in double conical shape. 5.5.4 LOW LEVEL GARDEN LIGHTING (BOLLARDS): The luminaires shall comprise of acrylic diffuser mounted on suitable MS pillar which shall house suitable control gears, starters, capacitors. The luminaires shall be suitable for GLS/PL lamps. 5.5.5 FLUORESCENT TUBE LIGHT FITTING WITH STOVE ENAMELED OPEN REFLECTOR: Industrial type fixture suitable for 2x40W/ 1x40W fluorescent lamp consists of reflector, made from CFCA sheet steel finished in stove enamel grey outside & white inside. 5.5.6 ACID PROOF FLUORESCENT TUBE LIGHT: It shall be suitable for 2x40W/ 1x40W fluorescent lamp comprised of rubber gasketed cast aluminium control gear housing with detachable cover incorporating ballasts, starter, capacitors and connector block. It shall be specially designed with rubber gasket to prevent entry of corrosive vaporous or dust. 5.5.7 MIRROR OPTICS FLUORESCENT TUBE:


It shall be suitable for 2x40W/ 1x40W fluorescent lamp comprises of CRCA sheet steel housing finished in stove enamel while inside and grey outside. Mirrors made of high purity anodized aluminium sheet giving a very high light output with wide spread light distribution. 5.5.8 DECORATIVE FLUORESCENT TUBE LIGHT: It shall be suitable for 2x40W/ 1x40W fluorescent lamp comprises of sheet steel housing fabricated from CRCA sheet steel, finished stove enamel white inside and outside. It shall consist of Acrylic diffuser which is supported by brown high impact polystyrene end plate. 5.5.9 CHANNEL MOUNTED FLUORESCENT TUBE LIGHT WITHOUT REFLECTOR It shall be suitable for 1x40W/ 2x40W Fluorescent lamps made out of CRCA sheet steel finished in grey stove enamel. The cover plate shall be finished in white stove enamel. 5.5.10 100W INCANDESCENT BULK HEAD FITTING: It shall be suitable for GLS lamp upto 100W and comprises of die cast aluminium alloy body, prismatic heat resistant glass cover held with a weatherproof gasket in a MS galvanized wire guard. It shall be painted in white stove enamel inside and grey outside. 5.5.11 COMPACT FLUROSCENT FITTING: It shall be suitable for 9/11/14/18W CFL, suitable for surface mounting and recessed mounting and made of CRCA sheet steel housing, finished in stove enamel white inside and grey outside, fitted with high purity anodized aluminium reflector and complete with control gear. 5.5.12 REFLECTORS The reflectors shall be made of CRCA sheet steel/ aluminium/ silvered glass indicated for all fittings. The thickness of steel/ aluminium shall comply with relevant standards. Reflectors made of steel shall have stove enameled/ vitreous enameled/epoxy coating finish. Aluminium used for reflector shall be anodized/epoxy stove enameled/ mirror polished.


Reflectors shall be free from scratches or spots and shall have a smooth and glossy surface having en optimum light reflecting co-efficient such as to ensure that the overall light output specified. Reflectors shall be readily removable from the housing for cleaning and maintenance. They shall be securely fixed to the housing by means of positive fastening device of captive type. 5.5.13 LAMP/ STARTER HOLDERS Lamp holders shall comply with relevant standards. They shall have low control resistance, shall have resistance to wear and shall be suitable for operation at the specified temperature without deterioration in insulation value. They shall hold the lamps in position under normal condition of shock and vibration met within normal installation and use. Lamp holders for the fluorescent lamps shall be of the spring loaded bi-pin rotor type. Live parts of the lamp holder shall not be exposed during insertion or removal of the lamp cap pins when in working position. Lamp holders for incandescent, mercury vapour & metal halide lamps shall be of Edison screw (E.S.) type. Starter holders for fluorescent lamps shall conform to the relevant standards. All material used in the construction of the holder shall be suitable for tropical use. The starter holders shall be so designed that they are mechanically robust and free from any operational difficulties. They shall be capable of withstanding the shocks met within normal transit, installation and use. 5.5.14 BALLASTS The ballasts shall be designed manufactured and supplied in accordance with the relevant standards. The ballasts shall be designed to have a long service life and low power loss. Ballasts shall be mounted using self locking anti vibration fixings and shall be easy to remove without demounting the fittings. They shall be in dust-light, non-combustible enclosures. The ballasts shall be of the inductive, heavy-duty, fitted with thermosetting, insulating, moisture repellent, polyester compound filled under vacuum. Ballasts shall be provided with tapings to set the voltage within the range specified. End connections end taps shall be brought out in a suitable terminal block, rigidly fixed to the ballast enclosure. The


ballast wiring shall be of copper wire shall be free from hum. Ballasts which produce humming sound shall be replaced free of cost by the contractor. Separate ballast for each lamp shall be provided in case of multi lamp fittings. The ballasts for metal halide lamps shall not be constant voltage type. Electronic ballast shall be used if directed by ENGINEER-IN-CHARGE. 5.5.15 STARTERS Starters shall have bimetal electrodes and high mechanical strength. Starters shall be replaceable without disturbing the reflector lamps and without the use of any tool. Starters shall have brass contacts and radio interference capacitor. The starters shall generally conform to the relevant standards. 5.5.16 CAPACITORS The capacitors shall have a constant value of capacitance and shall be connected across the supply of individual lamp circuits. The capacitors shall be suitable for operation at supply voltage as specified and shall have a value of capacitance so as to correct the power factor of its corresponding lamp circuit to the extent of 0.95 lag. The capacitors shall be hermetically sealed preferably on a metal enclosure to prevent seepage of impregnate and ingress of moisture. 5.5.17 LAMPS Incandescent (GLS) lamps shall be of clear type unless otherwise specified. The fluorescent lamps shall be Cool Day Light type unless otherwise specified and shall be provided with features to avoid blackening of lamp ends. The lamp shall have triple coil electrode with an anode ring and a triband phosphor coating. Mercury vapour lamps shall be of high pressure, colour corrected type with a high luminous efficiency. The discharge tube shall be made of high grade quartz.


Metal halide lamps shall be provided with internal diffused coating and the average lumen output shall be 19000 lumen for 250W and 32000 lumens for 400W and the lamp voltage shall not exceed 100 V for 250 Wand 128 V for 400W. The colour rendering index of the lamp shall be 93. The lamps shall be suitable for universal burning position and for use in open type luminaire. The lamps shall be capable of withstanding vibrations and the connections at lead in wires and filaments/electrodes shall not break under such circumstances. Lamps/tubes shall conform to relevant standards and shall be suitable for supply voltage and frequency specified. 5.6 CEILING FANS: The ceiling fans shall be designed, manufactured and tested as per IS: 374. The fans shall have totally enclosed capacitor start and run motor suitable for operating on 240v, single phase, 50Hz AC supply system. The fan shall be of double ball bearing type having 3 blades with a sweep of 1200/ 1400 mm or as per specification complete with suspension rod, canopies and mounting rollers. The regulators shall be modular type electronic step less regulator suitable for mounting on modular switch boxes. 5.7 EXHAUST FANS: The exhaust fans shall be of industrial type designed, manufactured and tested as per IS: 2312 and operating on 240v, single phase, 50Hz AC supply system. The exhaust fan shall be of ring-mounted type and shall be complete with louvers. It shall be designed for opening and closing automatically with air flow velocity. A separate bird screen made of brass wire mesh shall be provided with steel framework on the outer wall. 5.8 WIRES: PVC insulated multistranded copper wires of 1100V grade as per IS: 694 and IS Certification shall be used. The type and size of wires to be used shall be as indicated in the BOQ & drawings. The following colour shall be grouped for the wiring:


Three phase wiring Red, Yellow, Blue Single Phase wiring Red/ Yellow/ Blue Switched phase (wire from switch to light fan, bell, SA White socket etc) Neutral Black Earth Green No joint is permitted in the run of wires. 5.9 SWITCHES Switches, manufactured in accordance with IS: 3854 shall be used. Switches in areas where concealed wiring has been adopted shall be flush mounting piano/modular type unless otherwise specified. 5.10 RECEPTACLES Only three-pin type receptacles manufactured in accordance with IS:1293 shall be used with the third terminal connected to the earth. All receptacles shall be provided with a switch mounted on the same enclosure but shall be a separate unit to facilitate replacement by part. Flush mounting type receptacles shall be used in areas where concealed wiring has been adopted and surface type shall be used in other areas. 5.11 OUTLET BOXES Outlet boxes for sockets, switches, fixtures and fan regulators etc. shall be of minimum 16 gauge M.S. sheet 2.5 deep or as specified in BOQ. Junction/Outlet boxes shall be used in roof slab where concealed wiring has been adopted. Front cover plate shall be of Formica or modular of approved make or equivalent with colour to suit the walls. Outlet boxes shall be electro-galvanised after fabrication. Cover plate shall be fixed by cadmium plated brass screw and suitable C.P. brass cup washers. Samples of these shall be approved by Engineer-In-Charge. 5.12 CONDUIT AND FITTINGS Conduit shall be minimum 25 mm PVC pipe minimum 2 mm thick or as specified. Generally, polyethylene conduits shall be uses in concealed


wiring and for surface GI conducts in industrial building and ERW conduit in no-industrial building shall be used. Care shall be taken to see that all conduit ends have no buns and ends are neatly reamed to avoid damage to wires. All metal conduit accessories shall be only of threaded type. Pin grip or clamp type accessories are not acceptable. Samples of these shall be furnished for approval by Engineer-In-Charge at site, before installation. The maximum number of PVC insulated wires which can be drawn in conduits of various sizes shall be as given below: Nominal Cross Sizes of Conduits (mm) Sectional Area 20mm 25mm 32mm 40mm (Sqmm) 1.5 5 10 12 - 2.5 5 8 12 - 4.0 3 6 8 - 6.0 2 5 7 - 10.0 2 4 5 8 16.0 - 2 3 6 ________________________________________________________________ 5.13 STREET LIGHT POLES Lighting poles shall be fabricated as per drawings. The poles shall be Hot Dip Galvanized octagonal GI poles. The galvanization shall be in single dip to average 70 micron DFT having shaft wall thickness as 3 mm. Each pole shall be provided with an outdoor junction box which contains terminal connectors (size and the number of terminals shall be as per the requirement) and 6A SPN MCB for local control. Conduit shall be embedded in foundation for incoming and outgoing cables. Foundation for lighting poles will be made by the contractor as per drawing and the cost for the same including supply of cement and all the connected materials shall be deemed to have been included in the cost of pole. Lighting poles shall be numbered serially as per the direction of Engineer-In-Charge.


6.0 TECHNICAL SPECIFICATIONS FOR EARTHING FOR ELECTRICAL WORKS 6.1 GENERAL: The contractor shall provide the complete bonding & earthing of the neutral point of power system & non current carrying metal parts of all electrical equipments & apparatus. Each & every piece of electrical equipments & apparatus shall be connected to the main earth bus by means of branch main connection of earth continuity conductors. All electrical equipments, except those operating at extra low voltages shall be provided with an earth terminal. All types of electrodes comprising an earth system shall be connected together with a continuous ring of earth conductor. After installation tests shall be made to ascertain that the earth resistance hereinafter specified is obtained. If the required resistance value cannot be obtained, a sufficient number of additional electrodes shall be installed until the resultant resistance not exceeding the specified value can be obtained. In all cases, the electrodes shall be driven such that the zones of earthing do not overlap. Each earth electrode shall be connected to its associated earth conductor through a linked connection. The link shall be enclosed together with the link in a reinforced concrete hand hole with slab cover, which shall be set flush with the ground. A continuous earth ring of GI /Copper flat as specified shall be provided in the electrical room and connected to the earth electrodes. The resistance between any point on each earthing system and the earth electrodes shall not exceed 1 ohm. The overall resistance between the earthing installation and the general mass of earth shall be less than 1 ohm. The system earthing shall be carried as per IS: 3043. All non current carrying metal parts of electrical installation shall be earthed properly. All metal conduits, trunking cables, switch gears, distribution boards, lift fitting and all other parts made of metal shall be bounded together & connected by means of specified earthing


conductor to all efficient earthing system. All earthing shall be in conformity with Indian Electricity Rules. 6.2 EARTHING CONDUCTORS: Earthing conductors shall be of electrolytic copper / GI & shall be protected against mechanical injury or corrosion. Zinc coating shall be as per latest IS codes. 6.3 SIZING OF EARTHING CONDUCTORS: The cross sectional area of copper earthing conductor shall not be smaller than the largest current carrying conductor subject to an upper limit of 80 Sqmm. If the area of the largest current carrying conductor or busbars exceeds 160 Sqmm than two or more earthing conductors shall be used in parallel, to provide atleast half the cross sectional area of the current carrying conductor or busbars. All fixture outlet, boxes & junction boxes shall be earthed with multi-stranded copper wires. All three phase switches & distribution boards upto 60 amps, rating shall be earthed with 2 nos. distinct & independent 3 mm dia GI wires. All three phase switches & distribution boards upto 100 amps. Rating shall be earthed with 2 nos. distinct & independent 4 mm dia GI wires. All 200 amp & above switches shall be earthed with minimum of 2 nos. separate & independent 50x6 mm GI strip. 6.4 EARTH PIT DETAILS: Copper/Galvanised Iron (GI) earth plate of 600x600x3.15(Copper) mm / 600x600x6.3(GI) mm in size buried in specifically prepared earth pit of 3.2 meters below ground level with 40 kg charcoal & salt with alternate layers of charcoal & salt with 50 mm dia. C class GI pipe with funnel with wire mesh for watering & brick masonry block cover, heavy duty CI cover complete as per IS : 3043. Necessary connections shall be done using copper wire of 10 SWG, 25x3 mm copper strip or 25x6mm, 50x6 mm GI strips as per instructions and drawings using lugs, cadmium plated GI nut-bolts, bitumen washers/plugging etc. complete connected to nearest switch gears as directed & duly tested by earth tester. Pipe electrodes shall be of 3.6 M long 50 mm dia. class C GI pipe. The GI pipes shall be provided with holes at regular intervals as per IS : 3043.


6.5 RESISTANCE TO EARTH The resistance of earthing system shall not exceed 1.0 ohm. 7.0 TECHNICAL SPECIFICATION FOR TELEPHONE DISTRIBUTION SYSTEM 7.1 GENERAL The telephone system shall include providing main / sub distribution frames, interconnecting cabling, tag blocks inside the buildings, interconnecting telephone wires between tag block and telephone socket outlets. The telephone socket outlet shall be modular type or as specified in the bill of quantities. 7.2 MAIN TAG BLOCK The main / sub distribution frame shall be enclosed type made out of CRCA sheet steel of suitable thickness (2 to 3.15 mm). This shall house necessary number of terminations with tags as specified, with provision for terminating incoming and outgoing cables. The termination and the frame shall be of standard make. The frame shall be suitable for outdoor application with IP 55 protection. This shall be mounted on suitable civil foundation with necessary GI pipe sleeves for taking incoming and outgoing cables. Out door termination block, if require to be used, shall be with weather proof enclosure with locking facility housed with necessary brick and RCC foundation and excavation in soil etc. as required. 7.3 TELEPHONE CABLES All telephone cables shall be PVC insulated, copper conductor conforming to latest IS and EC standards. Telephone cables shall be armoured / unarmoured to suit the nature of application and as indicated in the Bill of quantities. All cables shall be run in vertical or horizontal trucking, conduits or cable trays suitably prepared for distribution and separated from electrical cabling / wiring in an appropriate manner so as to eliminate electromagnetic interference. All telephone wiring shall be run in dedicated conduits separate from power wiring. All telephone locations to be in accordance with instruction of ENGINEER-IN-CHARGE.


All cables shall be identified by tags and a schedule identifying each termination shall be issued to Engineer-In-Charge upon completion of the cabling installation. 7.4 TELEPHONE TERMINAL BLOCKS Telephone termination block shall be krone make as per latest standards. The termination block should have loop in loop out arrangements, as required. 8. INSTALLATION 8.1 GENERAL The installation shall be carried out in accordance with the Indian Electricity Rules, the codes of Practice of Bureau of Indian Standards and other relevant regulations. 8.2 MEDIUM VOLTAGE SWITCH BOARDS Switch Boards shall be floor mounted in the room on the pre-formed trenches constructed with top / bottom entry for cables or free standing on floor with top entry for cables. The portion of the trenches which is not covered by the switch board shall be covered with 6 mm thick checkered steel plates with suitable MS reinforcement if required. All unused cables entries shall be closed with suitable blind plugs or plates made from 4 mm thick sheet steel bolted to the gland plates. 8.3 MCB DISTRIBUTION BOARD MCB Distribution Board shall be fixed with bolts and nuts grouted to the wall concealed in the cupboards / niches provided or flushed / semiflushed directly into the wall. 8.4 WIRING PVC insulated wires shall be drawn through concealed PVC conduits / open metal conduits.


The wires of a circuit shall not run through the conduits switch / socket boxes of another circuit. A common draw box with hylam barrier separating individual circuit wires may be adopted to minimize the number of draw boxes. Wires shall be terminated at the switch boxes with suitable crimping type tinned copper lugs. The wring shall be carried out by looping the phase conductors all the switch box and control conductors at the lights, fans and sockets. For coping of sires in switch boxes, shrouded type multiway 10A / 20A rated connectors shall be used. 8.5 CIRCUIT WIRING The circuit wiring shall be from MCB distribution boards to first switch box and looping the consecutive switch box in the circuit including conduits and accessories. 8.6 POINT WIRING The following shall be deemed to be included in Light / Ceiling Fan / Exhaust fan / Call bell / 6A /15 A ,AC , Water cooler, Compressor , socket points etc : (a) Conduit & conduit accessories (bends, tee, deep junction boxes,

fan hook boxes) from switch box t point. (b) Wiring of point from switch to point. (c) Earth wiring of each point from switch to point. (d) Fixing accessories such as clips, nails, screws, fill plug, rent plug etc.

as required. (e) Modular range of plate type cover plate, control switch, box etc. (f) Junction boxes, pull boxes etc. (g) Connectors for termination of points. (h) Ceiling rose / Angel holder / Batten holder for light points. ( I ) 6 A socket outlet . ( j ) 6 A /15 A socket outlet and switch for socket points. (k) Cutting and chasing the wall for conduit & boxes installation and

making good the same in original finish after installation complete as required.

8.7 TELEPHONE WIRE


The telephone wire shall be drawn in the conduits provided for the purpose. It shall be terminated with standard termination accessories at the end of socket pin and Telephone junction boxes. 8.8 SWITCH / SOCKET BOXES Switch / Socket Boxes shall be concealed in the wall and the mounting height of the boxes shall be as indicated in the drawings. Generally the lighting switch box will be 1350 mm from FFL and sockets will be at 450 mm from FFL. The switch and socket front plates shall project beyond the switch / socket box. In the case of concealed conduit wiring, the joints between the box and the surrounding plaster are covered by the cover plate. The cover plate shall be fixed with brass cup washers and full threaded brass screws. 8.9 CEILING FANS Concealed type fan hook boxes shall be provided for mounting of the ceiling fans. The fan shall be fixed to the hook in such a way that the canopy covers the opening of the fan hook box. Necessary down rods and other accessories shall be included as required for complete operation. 8.10 EXHAUST FANS Exhaust fans shall be mounted on an MS ring which shall be 100 mm to 300 mm below the ceiling level. The boxes shall be covered with 3 mm thick hylam sheet of approved colour. In the case of concealed flush mounting, the hylam sheet shall project 6 mm beyond the box so that the joint between the box and the surrounding plaster is covered by the sheet/. The hylam sheet shall be fixed to the box with brass cup washers and full threaded brass screws. 8.11 LUMINAIRES The installation of luminaries shall be at fixed locations indicated in the drawings or as directed by Engineer-In-Charge with necessary fixing accessories. 8.12 CABLES


The underground cable shall be laid in excavated trenches outside the building. The trenches shall be excavated to a depth of not less than 800 mm and the cables shall be laid at a depth of 750 mm. The cables shall be laid over a 50 mm thick sand cushion at bottom and 250 mm on top of cable and shall be with bricks at either ends of trench and protected at top by slab/bricks. The gap between the cables and the bricks shall be fill with sand, after that for 400 mm (i.e.) upto firm ground level the cable trench shall be back filled suitably with soil. The cable trench shall have the widths as indicated by suitably excavating in types of soil to attain the required width. Cable makers shall be installed at every 30 m interval along all straight lines and at bends. The cable markers shall be of cast iron and shall have a clear and legible inscription LT CABLE. Wherever cables are required to enter the building the cable shall be through Hume pipe or GI pipe. Suitable packing shall be made at both ends of the pipes. Cables inside building shall be run in cable trays. Where cables are required to cross the roads, cables and pipes of other services the cables shall be drawn through Hume pipe or GI pipe. Suitable sealing shall be made at both ends of the pipes. Vertical runs of cables along the wall shall be laid through GI pipe of suitable diameter upto a height of 900 mm above finished floor level. The GI pipe shall be clipped to the wall with GI clamps and GI screws. The distance between the clamps shall not exceed 400 mm. The cable laying shall be done in such a way that there is no damage / injury to the cable. Adequate care shall be taken while pulling cable from drum and while laying. Sharp bends shall be avoided in the cable runs. The bending radius shall not be less than 12 times the diameter of the cables. No joints shall be permitted in the runs of the cables upto a run of 500 Metre. Where more than one cable has to be laid along the same route, the cables shall be laid horizontally touching each other and not one above the other.


The armour of the cables shall be effectively earthed at termination point through cables glands. Suitable phase identifiers shall be provided at the terminals. The cables shall be laid in preformed trenches wherever required. The preformed trench shall be RCC casting on all the sides. 50 x 50 x 6 mm MS angle at required intervals shall be fixed to the casting. The preformed trench shall be covered with RCC cover which shall be capable of taking the heavy vehicular load. The wall thickness of preformed trench shall be suitable to take al type of loads. 8.13 STREET LIGHT POLES Poles for external lighting shall be installed along the road / pathway edges as indicated in the drawing and shall be provided with cement concrete foundation below the ground level and above the ground level. The concrete used for the foundation shall be fixed in 1:1.5:3 proportions with stone aggregate of 20 mm nominal size. Concreting shall be done solidly to avoid honeycombing using shuttering. The depth and height of the concrete work shall be as per requirement of the pole heights as indicated in drawing or as advised by ENGINEER-IN-CHARGE. 8.14 STREET LIGHT LUMINAIRE The luminaire shall be installed at the locations indicated over the poles. The lamps shall be fixed after the luminaries are installed.

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