7.installation,operation & maintenance(iom)

7/24/2019 7.Installation,Operation & Maintenance(IOM)

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Installation,Operation&Maintenanceanual

PACV-S

Packaged Air Conditioners


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Table of Contents1 Introduction 4

Nomenclature . . . . . . . . . . . . . . . . . . . . 5

Safety Instructions . . . . . . . . . . . . . . . . . . 5Specic Hazards. . . . . . . . . . . . . . . . . . . . 5

Points To Remember. . . . . . . . . . . . . . . . . . 6

Component Features . . . . . . . . . . . . . . . . . 7

Liquid Line Controls . . . . . . . . . . . . . . . . . . 9

Electrical Control panel . . . . . . . . . . . . . . . 10

Room Unit . . . . . . . . . . . . . . . . . . . . . 11

2 Installation

Receiving of Equipment . . . . . . . . . . . . . . . 13

Rigging . . . . . . . . . . . . . . . . . . . . . . 13

Handling . . . . . . . . . . . . . . . . . . . . . . 13

Storage . . . . . . . . . . . . . . . . . . . . . . 14

Location & Space Requirements . . . . . . . . . . . 14

Pre-Installation Checkup. . . . . . . . . . . . . . . 15

Preparation For Installation . . . . . . . . . . . . . 16

Carrying Out Installation . . . . . . . . . . . . . . . 16

Condensate Draining . . . . . . . . . . . . . . . . 16

3 Operation

Pre-Startup Checklist . . . . . . . . . . . . . . . . 17

Pre-Startup Procedure . . . . . . . . . . . . . . . . 17

Service Record . . . . . . . . . . . . . . . . . . . 18

Unit Startup . . . . . . . . . . . . . . . . . . . . 19

Display & Keypad Operation . . . . . . . . . . . . . 20

Alarms . . . . . . . . . . . . . . . . . . . . . . . 21

List of alarms in the unit controller . . . . . . . . . . 21

Operation of the Room Unit . . . . . . . . . . . . . 22

Setting the address of the room unit . . . . . . . . . 22

switching in and switching off the unit . . . . . . . . 22

Commissioning Test Report . . . . . . . . . . . . . 25

4 Maintenance

Periodic Maintenance . . . . . . . . . . . . . . . . 26

Leak Testing, Evacuation &

Charging Procedures . . . . . . . . . . . . . . . . 28

Fan . . . . . . . . . . . . . . . . . . . . . . . . 32


3/65 | 3

Bearing . . . . . . . . . . . . . . . . . . . . . . 32

Fan Belt Adjustment. . . . . . . . . . . . . . . . . 33

Fan Pulley Adjustment

(For variable pitch pulleys only) . . . . . . . . . . . 35

Alignment of Shafts & Sheaves . . . . . . . . . . . . 35

Mold In And Around Drain Pans . . . . . . . . . . . . 36

Coil . . . . . . . . . . . . . . . . . . . . . . . . 37

Coil Cleaning . . . . . . . . . . . . . . . . . . . . 37

Compressor Oil . . . . . . . . . . . . . . . . . . . 37

Adding Oil . . . . . . . . . . . . . . . . . . . . . 37

Dismantling & Disposal . . . . . . . . . . . . . . . 38

Expansion valve service & maintenance . . . . . . . . 38

Hot gas by pass . . . . . . . . . . . . . . . . . . . 40

Refrigerant Recovery, Recycling &

Reclamation . . . . . . . . . . . . . . . . . . . . 43

Trouble Shooting . . . . . . . . . . . . . . . . . . 46

5 Appendix

Appendix I . . . . . . . . . . . . . . . . . . . . . 49

Loading Points . . . . . . . . . . . . . . . . . 49

Appendix II . . . . . . . . . . . . . . . . . . . . . 51

Dimensional Data . . . . . . . . . . . . . . . . 51

Appendix III . . . . . . . . . . . . . . . . . . . . 55

Refrigerant Piping Layout . . . . . . . . . . . . 55

Appendix V . . . . . . . . . . . . . . . . . . . . . 57

Filter Dimension . . . . . . . . . . . . . . . . 57

Appendix IV . . . . . . . . . . . . . . . . . . . . 58

Spare parts . . . . . . . . . . . . . . . . . . . 58

Appendix VII . . . . . . . . . . . . . . . . . . . . 57

Typical wiring diagram . . . . . . . . . . . . . . 57

Appendix VIII . . . . . . . . . . . . . . . . . . . . 62

Typical Wiring Diagram . . . . . . . . . . . . . 62

Appendix IX . . . . . . . . . . . . . . . . . . . . 63

Instructions For Downloading/Upgrading The

Software For Microprocessor . . . . . . . . . . . 63

Appendix X . . . . . . . . . . . . . . . . . . . . . 64

P-T Chart . . . . . . . . . . . . . . . . . . . . 64


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INSTALLATION, OPERATION & MAINTENANCE

This manual must be carefully read and followed in

order to avoid unnecessary/dangerous conditions in the

machine and to guarantee the safety of the equipment.

The contents in this manual are mainly the installation and

operating instructions of your Package Air Conditioning

unit. The precautions mentioned through out this manualshould be taken seriously to derive maximum safety forall. Installation, service and start up of any air-conditioning

equipment should be done only by a qualified personnel or

service technician. Always observe precautions in the manual

and be familiar of all the symbols / labels attached in the unit

when dealing or working with the equipment.

Unit DescriptionThe PACV-Sseries is a modern, diversified and environment

friendly series of packaged air conditioners which use R - 134a

as the refrigerant.

The complete PACV-Spackage provides an extremely rugged,

heavy duty, long-life, energy efficient and self-contained package

air conditioner that will provide cooling at higher efficiency overa long and extended life. What makes PACV-Sseries the prideof SKM products is the use of :

The SKM PACV-S series packaged air

conditioning units are durable, dependable,

strong, reliable, versatile, quiet and energy

efficient. Wherever a heavy duty packaged

air-conditioner is required, the PACV-Sseriesshould be an automatic choice.

Unit Name PlateTypical SKM Air Cooled Packaged Unit

nameplate is as shown.Check the nameplate data with the P.O/

Submittal when receiving the unit.

For the representation and understanding of the points

of caution, attention, danger, and information. Following

symbols are used throughout the manual.

Note:- It is not the intention of this manual

to cover all possible variations in systems

that may occur or to provide comprehensive

information concerning every possible

contingence that may be encountered during an installation,

operation and maintenance. If additional infor mation isrequired or if specific problems arise that are not fully

discussed in this manual, contact your local office.

Always heed all WARNING and SAFETY

INSTRUCTION boxes. Always read and heed all

instructions in this manual carefully. Failure to

follow WARNING, SAFETY INSTRUCTIONS and all

other instructions could result in severe personal

injuries and death.

Introduction

General Warning

CAUTION

General Information .

INFORMATION

Take special attention

and po in ts to be

noted.ATTENTION

Indicates dangers

through electricalshock, system

pressure, and

location.DANGER

Indicates dangers by

high voltage

HIGH VOLTAGE

Indicates dangers

by moving/rotating

parts

MOVING/ROTATING PARTS

HOT PIPES

Indicates dangers by

hot pipes

MODEL

Qty KW FLA

Qty KW FLA

MANUFACTURING SERIAL NO

MANUFACTURED IN SHARJAH,UNITED ARAB EMIRATES

HEATER KW/NO. OF STAGES

R-134A CHARGE(KGS)

CONDENSER MOTOR

EVAPORATOR MOTOR

MIN.CIR AMPS/MAX. FUSE AMPS

COMPRESSOR MODEL Qty LRA RLA

POWER SUPPLY (V/Ph/Hz)

CONTROL VOLTAGE(V/Ph/Hz)

Factory/Field

ITEM CODE

High efficiency totally sealed hermetic scrollcompressor.

Totally enclosed, Class F insulated, IP55

protected condenser and evaporator fan

motors.

Heavy duty condenser and evaporator coils

optimised in design for long-life maintenance

free operation.

Cabinet construction specifically designedfor Gulf climates.

IP 54 Electrical panel.

Factory installed, advanced and user friendlymicroprocessor based control system.

Interface capability with major BMS protocols

(option).


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SKM reserves the right tochange, in part

or in whole the specifi cations of its Air

Conditioning Equipment at any time in

order to add the latest technology. Therefore,the enclosed information may change without

any prior notice.

Nomenclature

Safety Instructions

Carefully read the content of this

manual before installing the air

conditioning equipment. For maximumsafety installers should always follow

the list of warnings. During the

installation process care should be

taken to avoid any accidents related to:

1. High voltage

2. High pressure in the system

3. Hot pipes due to discharge

temperature

4. Moving/Rotating parts

This manual explains how to install,

operate and maintain SKM PACV-S

series,Air coo led packaged unit . The

manufacturer shall not be responsible

for damages arising from wrong

practices used. So SKM recommendsto do the installation including the

connection of electricity, operation and maintenance

by a person qualified for the air- conditioning and

refrigeration work only.

The manufacturer shall not be responsible for

damages originating from unauthorized changes

or the improper connection of electricity and not

adhering to the operation limits included in the

manual. Also this shall invalidate the warranty.

The air conditioning equipment should be used

only for the applications for which it has been

designed.

Refer product name plate, wiring diagrams and catalogues

for the electrical characteristic, of the equipment to selectcorrect wire sizes and isolators prior to the insulation.

It is the responsibility of the user or the person installing

the equipment to provide proper grounding and branch

circuit protection according to NEC, Local & National

safety regulations.

This Air Conditioning equipment must be disconnected

from the mains if any repair work is to be carried out.

Do not use the units if damaged. If problems occur, switch

the unit off and disconnect it from the power supply.

The control ON/OFF switch in the control panel does not

disconnect the equipment from the mains and thus it is

not to be used as a safety switch.

Do not attempt to repair, move, alter or reinstall the unit. If

performed by an unauthorized personal, these operations

may cause electrical shock or fires.

Always remember to inspect the units, refrigerant tubes

and protection regularly. These operations should beperformed by a qualified personnel only.

Contact SKM After sales in case any technical support

is required.

PAC V - 5 1 008 S Y

Packaged Air

Conditioner

V-shaped condenser

construction

Power supply frequency

5 = 50 Hz

6 = 60 Hz

Power Supply CodeY: 380-415V/3Ph/50Hz

P: 440V/3Ph/50HzR: 380V/3Ph/60Hz

E: 460V/3Ph/60HzT: 220V/3Ph/60Hz

Scroll Compressor

(R-134a)Nominal

Capacity (TR)

No. of Refrigerant

Circuits

Specific Hazards

Do not stand or work under suspended loads.

Wear a hard hat, safety shoes and gloves.

Noise Emission

The sound emission expected in normal use of the fan

should be duly taken into account.

Wear ear defenders when

working near to or on the running

fan!

Rotating Shafts and Impellers

Objects fixed to rotating shafts and impellers can fly

off at an angle and cause serious injury.

Articles of clothing and hair can get caught in rotating

shafts and impellers.

Heavy Loads

The heavy weight of fans

and their components entail

the following risks during

maintenance:

Risk of being trapped,

crushed or cut by moving or toppling

machinery.

Danger of falling components.


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Being an electromechanical machine, the unit may fail or

cause difficulties. Remembering the following few points will

ensure correct and prompt rectification and continued optimal

performance.

Points To Remember

A correct installation ensuring proper clearances forcorrect condenser air flow and maintenance as per the

drawings shown for recommended clearances

Proper level base on foundation with appropriatevibration mount. All connections and hook up to be

followed as per instructions, which ensures long term trouble

free operation and performance.

If power fuse is blown off, be sure to replace the same

with a new fuse having pre designed Amperage. Donot use a steel wire or copper wire instead of proper

fuse. Genuine fuse ensures safety and proper protection.

Incorrect fusing may cause fire or trouble with your equipment.

Before replacing any fuse or opening any electrical

panel door, make sure the main switch is OFF.

Do not spray or sprinkle water directly over or into

the air conditioning equipment for cleaning becauseelectric insulations and terminal of the components

are opened.

Following a power supply interruption during operation,

the microprocessor is programmed to restart the unit

automatically when power supply has returned to normal.

Periodical maintenance of the unit will give better

performance in the long run than only break down

maintenance.

The microprocessor controller is programmed to stop

functioning the Air conditioning equipment includingthe compressor in the event of a safety device trips. The

problem should be investigated and repaired or rectified as per

trouble shooting instruction in this manual before attempting to

reset and restarting the machine.

This Air conditioning equipment is meant to be installedout doors and suitable to normal environment elements.

Do not try to cover or block any inlets or discharge openings

to condenser.

Insist on maintenance from a reputable maintenance

contractor to ensure a trouble free operation.

Do not remove guards

during operation.

Do not wear loose-fitting

clothing when working

near rotating shafts and

impellers.

Wear gogg les.

Hot Surfaces

There is a risk of sustaining burns or scalds

on hot surfaces during operation.

Do not touch the Motor,

Compressor bo dy, Discharge

line during operation.

When the condenser fan has

stopped wait until the motor

has cooled down.

Wear protecti ve gloves.

Electrical Shock Hazards

All p ower must

be disconnected

prior to installation

and servicing this

equipment. More

than one source of

power may be present. Disconnect

all power sources to avoid

electrocution or shock injuries.

Avoid breathingfiber glass dust.

Use a NIOSH approved dust/mist respirator.

Avoid contact with the skin or eyes. Wear

long-sleeved, loose-fitting clothing, gloves,and eye protection.

Wash clothes separately from otherclothing: rinse washer thoroughly.

Operations such as sawing, blowing,tear-out, and spraying may generate

fibre concentrations requiring additional

respiratory protection. Use the appropriate

NIOSH approved respiration in these

situations.

Fiber glass Insulation!This Product contains fiber glass wool. Disturbing

the insulation in this product during installation,

maintenance or repair will expose you to airborne

particles of glass wool fibers and ceramic fibers.

All necessary Personal Protective Equipment

(PPE) including gloves, eye protection, mask,long sleeves and pants must be worn when

working with products containing fibreglass

wool. Exposition to glass wool fibers without

all necessary PPE equipment could result in

cancer, respiratory, skin or eye irritation, which

could result in death or serious injury.


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Compressor

Compressors used in PACV-S packaged unit series are

hermetically sealed, compact scroll with the following features:

Vacuum operation!Compressor damage!

Scroll compressors should never be

used to evacuate a refrigeration or

air-conditioning system.

Do not pump down the scroll

compressor into a vacuum!

Three phase compressors

only: On initial startup, if

the compressor sound isabnormally high and the readings

of suction and discharge pressures

are outside normal range, there is

a possibility that the compressor

rotation is in the reverse direction.

In this case, interchange any

two legs of the power supply

and attempt to restart. Running

a scroll compressor in reverse

direction for an extended period

of time will cause damage to the

compressor. such damage is not

covered under manufacturers

limited warranty.

Reverse rotation for 5 to

15 minutes will result in

the overheating of motor

windings. In thi s case, the thermostat

in the motor windings open and

result in stopping of the compressor.

Continued reverse operation of scroll

compressor will result in failure of scroll

compressors. Such failures are

Component Features

High Efficiency.

Quite operation, Low Sound levels.

Compact and light .

Limited wear.

70% fewer moving parts than comparably sized

reciprocating compressors

Unique ability to handle liquid refrigerant.

Suction gas motor cooling.

Centrifugal oil pumps with filter and magnet.

Brazed fittings or Rotalock as options.

Multiple refrigerant circuits on larger units provides

efficient part load.

Parallel Operation

A parallel compressors installation, with common suction line

and common discharge line, gives a reduced operating cost

through greater control of capacity and power consumption. This

is achieved by staggering compressor switch-on sequences that

allow the parallel system to match its power with the capacity

needed. By switching-off individual compressor from parallelinstallation, while other compressor is operating 100%, the

improved part load efficiency can be achieved. The specially

developed and adopted oil equalization system ensures correct

compressors operation, oil balancing between compressors and

reliability.

Condensers

Condenser coils are manufactured of seamless copper tubesmechanically bonded to aluminum

fins to ensure optimum heat transfer.

All coils are tested against leakage by

air pressure of 450 psig (3100 kPa)

under water. All standard coils are

2,3 or 4 rows/14 FPI, 3/8 (9.5 mm)

O.D. tubes. An integral subcooling

circuit is provided to increase the

cooling capacity, without additionaloperating cost.

For different application requirements,

other optional condenserfin materials

are available:

Copper fins. Electrotinned Copper Fins.

Copper finned coils with electro-tinned after manufacturing.

Precoated Aluminum fins

The pre-coated is hydrophobic polyurethane resin. This optionprovides substantial corrosion protection beyond standard

coil construction.

Aeris Guard Coil Coating

The Aeris Guard Coil is a self etching high performance

modified epoxy finish that is specifically designed to coat

and protect Aluminum and Copper surfaces. In addition, the

coating is ideal for the protection of ferrous and non ferrous

materials.

SKM PACV-Sseries, all models, are restricted to a 14FPI (1.8

mm) fin spacing condenser coil. Gulf dust storms and the general

level of available maintenance in Gulf countries ensures this

condenser coil design shall provide long life and maintenance

free operation with the least possibility operational blockage on

the condenser. Ample condenser surface and sensible air flow

across the condenser ensures a low temperature differentialbetween condensing temperature and the high Gulf ambients

making thePACV-Spackaged unit perform efficiently and durably.

NOT covered under the manufacturers limited

warranty.


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Condenser Fans

Condenser fans are

propeller type, aluminium

alloy blades, directly driven

by electric motors. Motors

are Totally Enclosed Air Over(TEAO) six pole with class F

insulation and minimum IP55

protection. The TEAO and class F insulation features ensurelong life and are unique for SKM.

The motors are factory wired, using wires specially selected forhigh ambients operation, to unit control panel where the motor

contactors are located to control the operation of these motors.

The condenser fans are individually statically and dynamically

balanced at the factory.

Complete fan assembly is provided with suitable acrylic coated

fan guard.

EvaporatorEvaporator coils are manufactured of seamless copper tubes

mechanically bonded to aluminium fins to ensure optimum

heat transfer. All evaporator coils are tested against leakage

by air pressure of 300 psig (2068 kPa) under water. The DXevaporator coils are complete with headers of seamless

copper tubing. Supply headers incorporate a correctly sized

distributor. For different application requirements, other

evaporator coil material and/or treatment are available

on request.

Evaporator coil supplied with suitable size

thermostatic expansion valve(s) and multi-

circuited distributors providing capacitymodulation to match the compressors. The cross

wave fins and staggered tubes design uses the

evaporator surface effectively by creating uniform

air turbulence and optimum heat transfer over the

entire finned surface. Requirements for higher

face velocities can be handled by use of moisture

eliminators to avoid carryover.

Copper fins.

Electrotinned Copper fins.

Copperfinned coils with electro-tinned after

manufacturing.

Precoated Aluminum fins.

The pre-coated is hydrophobic polyurethane

resin. This option provides substantial

corrosion protection beyond standard coil

construction.

Aeris Guard Coil Coating.

The Aeris Guard Coil is a self etching high

performance modified epoxy finish that is

specifically designed to coat and protect

Aluminum and Copper surfaces. In addition,

the coating is ideal for the protection of

ferrous and non ferrous materials.

Fan Section

Fans in the PACV-S units are selected for the best sound

characteristics based on maximum fan efficiency. More than one

arrangement of evaporator fans are used in the PACV-Sseries

packaged units due to the wide range of air flow rates.

Commonly, all fans are double inlet, double width, centrifugaltype with forward curved impellers provide the combination of

efficiency and quietness of operation. All fans are statically and

dynamically balanced, belt driven by motor sizes up to 15 kW are

provided with adjustable pitch pulleys as standard.

Above 15 kW motor sizes are equipped with fixed pitch pulleys

s standard and adjustable pitch pulleys are option. Specify PP.

Single fan is used for PACV-51008S, PACV-51010S, PACV-

61009S & PACV-61012S models. Models PACV-51014S~PACV-

52055S & PACV- 61018S~PACV- 62066S are equipped with twofans. These fans are mounted on a single heavy duty shaft driven

by a single electric motor. Shaft end insert into over sized, tapered

lock self aligning long life bearings. The motor is mounted on

an adjustable base, so that belt tension can be easily adjusted.

Models PACV-52065S and PACV-62076S onwards, use singlefan assembly, which has maximum strength, high performance,

quietness and reliability. These fans use self aligned ball or pillow

block bearings that are greased for life. Pillow block bearings

are provided with re-greasing fittings. The motor is mounted on

an adjustable base, so that belt tension can be easily adjusted.

The complete fan-motor drive assembly is mounted on a floating

sub-base. In order to limit transmission of noise and vibration,

the complete fan motor sub-base assembly is mounted on anti-

vibration mounts. Flexible connection is provided between fandischarge and casing panel to avoid transmission of vibration to

the connecting duct.

The optional modular construction units for models PACV-

51008S~PACV-52055S & PACV-61009S~62066S are also using

the same fan specifications as mentioned above.

The electric motors are foot mounted, 4 pole, totally enclosed fan

cooled (TEFC), IP-55 protected, Class F insulation with Class

B temperature rise.

Drive package is factory selected for the medium air flow rate as

shown in the capacity ratings. Alternative drive packages to meet

specific job or client requirements can be provided.

Refrigerant Circui t

PACV-S series comes complete, as standard, with correctly

sized and piped refrigerant lines including sight glass, filter drier,

thermostatic expansion valve, solenoid valve, shut-off valve, and

a full operating charge of R-134a in each circuit.

Piping is fabricated from ACR grade copper piping. Suction line isinsulated with (12 mm) wall thickness closed cell pipe insulation.

Filter Section

PACV-Sseries can be with a range of filter sections and filters

to meet requirements for the most demanding applications.

Flat or vee filter sections to accommodate 1 or 2

cleanable aluminium media filters can be provided.

A bag filter section to house 22, 30 or 36 deep

bag filters having efficiencies as desired can also

be provided, as required. Filter sections come with

latches to provide easy access for removal and formaintenance.


9/65 | 9


Shut Off Valve/Ball Valve

Usually used so that portions of refrigeration system can be

isolated for service or repairs.

Sight glass

Used to observe the flow of liquid refrigerant. Bubbles or

foaming in the sight glass indicate a shortage of refrigerant or

restriction in the liquid line that can adversely affect system

operation. Sight glasses are widely used as a means of

determining if the system is adequately charged.

Filter Driers

Driers are mounted in the refrigerant liquid line to ensure that

all the refrigerant in circulation passes through the drier each

time it circulates through the system so as to remove any

moisture or foreign matter from the refrigerant stream.

To order a sand trap louvre from SKM specify fresh air opening

size with option ASL.

Casing/Structure

Designed for ease of handling and low cost to install. ThePACV-S

Air Cooled Packaged Units are factory assembled and mounted

on a rigid base. The unit casing used in PACV-SPackaged units

is made of zinc coated galvanized steel sheets conforming to

JIS-G 3302 and ASTM A653 which is phosphatized then bakedafter an electrostatic powder coat of approximately 60 microns.

This finish and coating pass a 1000 hours in 5 % salt spraytesting at 95F (35C) and 95% relative humidity as per ASTM

B117. The entire casing panels are designed to be leak proof

against rain and ensure rain cannot enter the PACV-Sseries

packaged air conditioner interior. Evaporator section sealed

by the use of vinyl gasketing material.

The evaporator section is insulated from all sides with black-

neoprene faced heavy density 1 thick fiber glass insulation

for models up to PACV-52055S & 62066S and 2 thick

fiber glass insulation for models PACV-52065S & 62076S

onwards. The insulation cum sound liner meets the fire

requirements of NFPA90A and is secured with mechanicalfasteners in addition to water resistant adhesive.

For applications requiring an inner skin in the evaporatorsection, option DSE provides 0.7 mm galvanized inner

skin. Suitable isolation to ensure no cold-bridges

and no condensation on the exterior of the unitsis provided. The condensate drain pan is heavily

insulated to ensure that condensation may not

occur. Stainless steel condensate drain pans are

available on request.

Liquid Line Controls

Thermostatic Expansion Valve

For controlling the flow of liquid refrigerant into

the evaporator, an orifice in the valve meters

the flow into the evaporator, the rate of being

modulated as required by needle type plunger

and seat, which varies the orifice opening.

On 100% fresh air applications an initial sand

trap louvre can effectively minimize entrance

of sand into the air stream. High efficiency mini pleat panel filters are

available as an alternative for bag filter where

space is limited. Filter sections come with

latches to provide easy access for removaland for maintenance.

Low Pressure Switch

This switch is fitted in the suction side of each refrigerant circuit

and is wired to the unit controller digital input. Its function is to

protect the compressors against low suction pressure. If therefrigerant circuit is On to meet the cooling demand and this

switch remains open for a specific time (low pressure alarm delayset point), then the unit controller will switch off that circuit and

generate Low suction pressure alarm.

Solenoid ValveIt is used to stop the flow of refrigerant within

the refrigeration system.

The valve is typically a normally-closed type of

valve so that it is closed when it is energized


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10 |

Electrical Control PanelThe unit mounted control panel enclosure is fabricated out of heavy

gauge sheet steel in phosphatized powder coated baked finish.

The enclosure conforms to IP54 as per guidelines in IEC 529. A

hinged access door and key-fastener is provided for easy access

and security. The panel is factory wired in accordance with NEC430 & 440, labelled, tagged and features 220V/240v controls.

All compressors are with DOL starting.

Individual compressor, condenser fan motors and evaporator

fan motor contactors.

Motor protector circuit breaker for condenser and evaporator

fan motors.

Control circuit breaker.

Control circuit on/off switch.

Microprocessor control boards.

Control Relays.

Power and control terminal blocks.

Microprocessor Controller

All PACV-Sseries package units are equipped with a full function

microprocessor based controller as a standard feature. Thecontroller is factory programmed for the control of evaporator

fan, compressors and condenser fans. The controller comes

with a built in keypad and display for simple but meaningful man

machine interface. This controller provides complete operational

control for the unit and has built-in auto diagnostic capability

that can signal normal operation or alarm conditions as well asshutting down the unit or system if necessary.

.The Main Features of the controller are as follows:

Built in LCD display with back light.

Roll & push knob and 3 function buttons.

Battery backed up built in real time clock.

Multiple authorization level to provide tight security

for the control system.

Capacity control based on room temperature or

return air temperature.

Alarm history.

A sleek & elegant design room unit.

Discharge Pressure Transducer

This transducer is fitted in the discharge side of

each refrigerant circuit and is wired to the analogueinput of the unit controller. Through this transducer,

the unit controller will monitor the discharge

pressure of the refrigerant circuits and cycle thecondenser fans (when compressors are running)

in order to maintain proper head pressure.

Facto ry se t t ings fo r p ressu re

switches and Fan cycling

Factory Switch Settings

DescriptionCut Out

(PSIG)

Cut In

(PSIG)

Low Pressure

Switch14.5 29

High PressureSwitch

300 200

Table 1

Factory Fan Cycling Settings

in Unit Controller

(Units with 4 fans)

Description On (PSIG) Off (PSIG)

Fan Cycling

Stage- 1180 130

Fan Cycling

Stage- 2200 150

Fan Cycling

Stage- 3220 170

Fan Cycling

Stage- 4240 190

Table 2

digital input. Its function is to protect the compressors

against high discharge pressure. If this switch

remains open for one second, then the unit controllerwill switch off the corresponding refrigerant circuit

and generate High Discharge pressure alarm.

High Pressure Switch

This switch is fitted in the discharge side of each

refrigerant circuit and is wired to the unit controller


11/65 | 11


Display Information

SKM Pacvs series package units offer LCD

display which allows the operator to accessdifferent parameters of the unit. Operator can

view and change the unit parameters. The display

information includes: Status

Outputs

Inputs

Alarms

Set points

Password

System Protection

The intelligent microprocessor based controller

monitors all the safeties related to the unit and

makes the necessary protections,by shutting

down the entire unit or the effected circuit. Theprotection includes

Low suction pressure. High discharge pressure.

High compressor motor temperature. (For

compressors with internal motor protector).

Compressor short cycling.

Evaporator fan motor overload

BMS Connectivi ty (Optional)

Volt free contacts for run status, common fault

status, auto mode status and provision for remote

on/off shall be provided as option if required.

In addition, the PACVS microprocessor can

support the major BMS protocols such as BACnet,

Modbus & LON. Extra hardware may be required

depending on the protocol.

Room UnitThe controller comes with a loose supplied sleek

and elegant design room unit for installing in the

conditioned space. Communication between

unit controller and room unit is through two

wire interface. The communication cable

should be 2 core, twisted pair, unscreened

with stranded conductors, as per KNX

specification. Maximum distance between room

unit and controller can be 700 meters. The room

unit has a built in sensor for measuring the room

temperature. It transmits room temperature,

set point, unit operating mode etc. to the unitcontroller. Control of the compressors is based

on room temperature and the set point, as

standard. If unit control needs to be based

on duct temperature, please specify during

time of order.

Room unit display (Operator Controls)

ON/OFFButton for unit power on or unit

power off

Program

Button for Time scheduler, pressing

this button allows date/time setting,while holding it allows schedule

programming

Minus

Button for set-point adjustment,

each operation of the Minus (-)

button reduces the set point by

differential which is defined in

controllers setting

Plus

Button for set-point adjustment,

each operation of the Plus (+)

button increases the set point by

differential which is defined in

controllers setting

OK

Button for confirmation of date/time

and scheduler settings. Long pressof this button can toggle between

measurement units -oC and oF

FanButton for fan mode either

continuous mode or auto mode

Mode

Button for unit mode: Cool, heat,

ventilation and or cool-heat

auto changeover (*Cool-Heat

is available only if heat mode is

applicable)

Control or data communication

cables should not be routed alongwith power cables. Sufficient distance

is to be maintained while routing the cables

between Power and data communication cables

(If any).

Room Unit Installation

Installation must be carried with unit

power off.

Table 3

A brief description of each button in the room unit is shown in

table below:


12/65 12 |12 |

Figure 1

Figure 2

Step Two: Remove back cover

Open the back cover of the room unit as shown

using a screwdriver.

Step Three: Back plate Wiring

Install wiring into terminal blocks as indicated,

and push slack wire back into wall or junction box.

The communication cable between

room unit and microprocessor

controller should be 2 core, twisted pair,

unscreened with stranded conductors (As per

KNX Specification). Maximum distance between

room uni t and con troller can be 700 meters.

Step Four: Cover Installation

Install cover plate as shown. Cover plate may be removed using

a screwdriver as needed to access the terminals for wiring.

The room unit is not protected against

accidental connection to AC 230 V

The microprocessor controller & room

unit include electrical and electronic

components and must not be disposed

off as domestic waste. Current local laws on

disposal of electronic waste are to be observed.


Step One: Location and Mounting

Select a mounting location with good air circulation away

from ventilation inlets, doors, windows, or other fresh air entry

points or near direct heat sources. For room installation, the

room unit should be mounted at least 4-1/2 feet above thefloor. Avoid direct sunlight and draught. Admissible ambient

conditions are to be observed.The room unit is designed for semi-flush surface mounting

with recessed conduit box. Cable entry is through the rear of

the unit. The unit comprises front housing and rear housing.

These can be locked together and released by snap

mechanism. Both the housings are plastic. Use the backplate as a template for locating holes for screws and wiring.

Mount the back plate using screws provided. Wall anchors

are recommended for drywall installations.


13/65 | 13

INSTALLATION,

Use all lift ing point s. Improper lifting can

cause severe personal injury and property

damage.

a. Support the unit well along the length of the base rail

b. Level the unit (no twists uneven ground surface)

c. Provide proper draining around the unit to prevent

flooding of the equipment

d. Provide adequate protection from vandalism,

mechanical contact, etc.

e. Securely close the doors

f. Cover the supply and return air openings an limits

without isolation dampers.

Rigging holes are provided on the sides of the unit.

Avoid twisting or uneven lifting of the unit

The cable length from bracket to the hook should always

be longer than the distance between the outer lifting points.

If the unit is stored at the construction site for an intermediateperiod, follow these additional precautions:

HandlingReceiving of Equipment

Responsibility should be assigned to a

dependable individual at the job site to

receive material. Eachshipment should be

carefully checked against the bill oflading. The shipping receipt should

not be signed until all items listed on

the bill of lading have been accounted

for.

When uncrating, care should

be taken to prevent damage.Heavy equipment should be

left on its shipping base until it has been

moved to the final location.

Check carefully for concealed damage. Any

shortage or damages should be reported to the

delivering carrier. Damaged material becomes thedelivering carrier s responsibility, and should not be

returned to the manufacturer unless prior approval is given

to do so.

The packing list included with each shipment

should be carefully checked to determine if

all parts and equipment have been received.Any accessories such as starters, contactors

or controls should be fastened to the basic unit to avoid

loss and prevent possible interchanging with other

units.

Make sure that wiring diagrams and

IOM manuals are available within theequipment control panel.

Rigging

Regardless of the packaging

used in transporting of the units, it

should preferably be lifted with a fork

lift truck or a crane and belts. The

units should be unpacked as close

as possible to its final installation position. The

unit should always be left standing upright.

Before positioning the unit, it is advisable tore-check the weights.

Remove the wooden pallet from underneath

the machine before installation

Use protectors to prevent sling or cable as

per Figure 3-4.

All protection/spreader bars shown in the

rigging illustration should be provided by the

customer on site.

WOODEN PIECE

HOOK

SLING

SHACKLE

WOODEN PIECE

SPREADER

SHACKLE

4No.EQUAL SLING

HOOK

Figure 3

Figure 4


14/65 14 |

INSTALLATION,

Storage Single Unit Installation

Table 4

Location and Space Requirements

When thePACV-Sunits need to be stored in a prolonged

period prior to installation, the following protective

measures are required: Units must be stored in a protected area and

safe from construction debris. Do not remove thewooden coil guard.

Check the pressure in high pressure side of

refrigerant circuit to confirm that the refrigerant

charge is intact in every three months. Take note

of the ambient while checking. Contact SKM After

Sales Office or SKM sales representative.

Keep the liquid line Shut Off valve closed.

When selecting a location for the unit, the following

points should be considered:

There should be enough space for air movement

beside the condenser coils which should beapproximately equal to the height of the coils.

The discharged air from the condenser fan should

not be obstructed by any roofing, ducting etc whichcould cause air short circuiting.

There should be sufficient area provided to enable

for the servicing of the unit.

The schematic shown in Figures 5-9 gives the

recommended clearance areas around the unit for

both maintenance and air flow.

A B C

51008-S 61009-S

51010-S 61012-S

51014-S 61018-S52015-S 62018-S

51017-S 61020-S

52017-S 62020-S

52020-S 62024-S

52023-S 62028-S 54

52026-S 62033-S

52030-S 62036-S

52032-S 62037-S

52038-S 62046-S

52045-S 62055-S

52050-S 62060-S

52055-S 62066-S 86

52065-S 62076-S 78

53070-S 63085-S53075-S 63090-S

53080-S 63095-S

53085-S 63100-S 108

53090-S 63105-S 114

53095-S 63110-S 121

54100-S 64120-S 124

54110-S 64130-S 128

54115-S 64136-S 134

54125-S 64145-S 142

ALL DIMENSIONS ARE IN INCHES

72

78

72

82

66

96

104

78108

PACV-S

50

52

-84

6066

SPACING FOR SERVICE

DUCT

A

B

A

PACV- 51008 S TO 52055 S

PACV- 61009 S TO 62066 S

Figure 5

SPACING FOR AIR FLOW

[1981]78

A

A

PACV- 62076 SPACV- 52065 S

DUCT

B

DUCT

Figure 6

[1165]46

A*

B

A

*

PACV- 63085 S TO 64145 S

PACV- 53070 S TO 54125 S

DUCT

DUCT

SPACING FOR BOTH AIR FLOW AND SERVICE*

Figure 7

Figure 8

DUCT

C

DUCT

B

SPACING FOR SERVICE SPACINGFOR AIR FLOW

PACV- 61009 S TO 62066S

PACV- 51008 S TO 52055S

Multiple Unit Installation


15/65 | 15

INSTALLATION,

Multiple Units Installation (Modular

Construction)

t.

Recommendations

It is a necessity that the units are installed with adequate

free space around them to ensure proper circulation ofair that is rejected by the condensers and to provide

adequate space for unit access for servicing and

maintenance. There is a possibility of recycling of air

if the rejected air from condenser encounters any

obstacles leading to an increase in the ambient air

temperature surrounding the units.

Air distribution across the entire heat exchange

area will be impaired if the air outlet is obstructed.

These conditions lead to a reduction in the

heat exchange capacity of the coils causing

an increase in discharge pressure of the

compressors. This leads to a loss of capacity &increase in compressor power input

Units should not be

completely shrouded

with higher uninterrupted

wind shield in order to prevent

reversing of airflow. In case, sucha confi guration cannot be avoided,

a properly designed exhaust duct

or hood that does not influence

any additional pressure a properly

designed exhaust duct or hood that

does not influence any additional

pressure on the fans and which of the

same hight as surrounding shield to be

installed.

PACV- 51008 S TO 52055S

PACV- 61009 S TO 62066S

DUCT

DUCT

B

If there are walls on one or two adjacent sides of the unit.

The walls may be of any height. If there are walls on more

than two adjacent sides of the unit. The walls should not behigher than the unit.

Do not locate outside air intakes near exhaust vents or

other sources of contaminated air.

If the unit is installed where windy conditions are common,

install wind screens around the unit.

Units surrounded byscreensor solid walls must have no

over head obstructions over any part of the unit.

The area above the condenser must be installed

unobstructed to allow vertical air discharge.

A flat concrete foundation or floor which can support the

weight of the equipment must provided as the unit must be

level for proper operation and functioning of controls.

Under certain critical conditions it is recommended thatvibration isolators of rubber-in-shear or spring type beinstalled under the base refer to loading points(Page 49).

Electrical

Pre-Installation Check-Up

IMPORTANT: When installi ng t he unit , always

disconnect the electric supply.

Make sure that the power supply is compliant with current

safety standards. Always install the air conditioner in

compliance with current local safety standards.

Verify that suitable grounding connection is available.

Verify that the voltage and frequency of the power supply

comply with the specifications and that the installed poweris sufficient to ensure the operation of any other domestic

appliance connected to the same electric lines.

Verify that the air conditioner is connected to the power

supply in accordance with the instructions provided in the

wiring diagram included in the manual.

Verify that electric connections (cable entry, section

of leads, protections....) are compliant with the electric

specification and with the instructions provided in the

wiring scheme. Verify that all connections comply with the

standards applicable to the installation of air conditioners.

Figure 9

Foundation

A flat level concrete foundation which can support the weight of

the equipment must be provided.

Where units are to be located, over steel trusses or on a steel

platform, careful analysis to ensure proper distribution of weight

onto the structural members should be ensured. The steel platform

should be strong enough to hold the operating weight.


16/65 16 |

OPERATION

Avoid installing the equipment in the

following:

In areas where it is exposed to

direct sunlight. Close to any heat

source.

In damp areas or locations where

it could come into contact with

water.

In areas where curtains and

furniture could affect the supply

and discharge of air.

In areas in which there is no

enough space around the unit.

(Must install as per the required/

recommended spacing, shown in

the lay out drawings).

On surfaces that are unable to

support the weight of the unit

without deforming, breaking or

causing vibrations when the unit

is running.

General

Do NOT install the equipment in a location

where it will come in contact with the

following elements :

Combustible gases

Saline air

Machine oil

Sulphide gas

Special environment conditions,

if you must install the unit in such

conditions, first consult SKM.

Carrying Out Installation

1. Unpack the unit carefully.

2. Unfasten or dismantle transport locks.

3. Packing material to be fully removed and disposed.

4. The unit base frame must be fixed without stresses to the

supporting structure.

5. AVM to be regularly placed around centre of gravity and

firmly fixed. Check whether AVM is balanced under load.

6. No forces or vibrations may be transferred from other plant

parts.

7. The flexible connections at intake and/or discharge should

be installed, well aligned and freely moving.

8. The AVM should be freely moving and under even load.

9. The impeller should be turning idly and should not touch

the intake cone.

10. The stability against collapse of the unit should be checked.

Preparation For Installation

When deciding on the location of the unit with the

owner, the following restrictions must be taken into

consideration:

The discharge air from the condenser fan

should not be obstructed by any roofing,

shelter, ducting etc. Any obstruction will

cause short circuiting of condenser fans leading

to reduction in capacity or nuisance tripping of

the PACV-Spackage unit from the high pressure

control and sometimes in motor burnout .

Condensate Draining

It is mandatory to install a properly sized drain trap in order toensure proper draining of condensate collected in the drain pan.

Below mentioned are recommendations for sizing a drain trap.

Measure the maximum negative static pressure upstream from

the fan. The height H1 shown in belowfigures must be greater

than or equal to the negative static pressure at design conditions.

Ensure that there is sufficient water in the trap before starting in

order to maintain the seal.

H1= 1 f or each 1 of negative static pressure + 1

H2= H1/2

H= H1 + H2+ Pipe Diameter + Insulation

Condensate traps serving the cooling coils should be of sufficient

height to be effective.

The unit should be located on a suitable base to provide adequate

height from the ground in order to accommodate the drain trap.

Figure 10


17/65 | 17

OPERATION

Pre-Startup Procedure

After the installation has been completed, the following points

should be covered before the system is placed in operation.

Precaution: Carry out a fan test run

Risk of injury from rotating impeller!

Never reach into t he impeller when the fan

is in operation.

a. Check electrical connections. Be sure they

are all tight.

b. Observe compressor oil level before start-up.

The oil level should be at or slightly above the

center of the sight glass. Use only oil approved

by compressor manufacturer.

c. Remove or loosen shipping retainers undermotor- compressors. Make sure hold down

nuts on spring mounted compressors are nottouching the compressor feet.

d. Check high and low pressure controls,pressure regulating valves and all other safety

controls, and adjust if necessary.

e. Check refrigerant used in the system.

f. Wiring diagrams, instruction bulletins, etc

attached to PACV-S units should be read

and filed for future reference.

g. Make the proper refrigerant connections

and charge the unit with the refrigerant to

be used. Weigh the refrigerant drum before

charging so an accurate record can be kept

of the weight of refrigerant put in the system.h. Observe system pressures during charging

and initial operation. Do not add oil while the

system is short of refrigerant, unless oil level

is dangerously low.

i. Continue charging until system has sufficient

refrigerant for proper operation. Do not over-

charge. Remember that bubbles in a sight

glass may be caused by a restriction as well

as a shortage of refrigerant.

j. Do not leave unit unattended until the system

has reached normal operating conditions and

Pre Startup Checklist

Make sure the power supply voltage and frequency

are as given in the unit name plate.

Make sure that unit has been installed in accordance

with the installation instruction and applicable codes.

Check all electrical connections in unit control panel;

tighten them as required.

Make sure the compressor oil level is within the

sight glass range.

Check the power supply phase sequence for proper

direction of rotation of motors.

Make sure all system hand valves are in fully open

position and system contains an operating charge

of refrigerant.

Switch on the power supply to the unit

Crank case heaters of all compressors to be

energized at least 24 hours prior to start up.

PACV-S unit is factory charged

Please make sure to open supply air

dampers fully (if any) before starting the

fan motor. Otherwise, blower fan can be

damaged due to back pressure and warranty

will be void.

Take measures to prevent centrifugal fan

from being switched on accidentally.

Clear the ducting system and fan of all foreign

bodies (tools, small parts, construction

waste, etc.).

Close all the inspection openings.

Switch on fan and check direction of rotation

of impeller by comparing it with the arrow on

the fan indicating the direction of rotation. If the direction of rotation is wrong, reverse

the polarity of the motor having due regard to

the safety instructions.

Once operating speed has been reached

measure the current consumption and

compare it with the nominal motor current on

the fan type plate or motor rating plate.

If there is continuous overload switch the

centrifugal fan off immediately.

Check that the fan runs smoothly and quietly.

Ensure that there are no unusual oscillations

or vibrations.

Check the motor for any abnormal noises.

Prior to starting up the unit, we

recommend checking if the following

steps have been carried out:

the oil charge has been properly adjusted to maintain the oil level

at the center of the sight glass.

If the state of the fan does not allow adapted

action for repair it has to be put out of

order immediately and to be replaced if

required.


18/65 18 |

OPERATION

Operational Check-Out

After the system has been charged and has operated for

at least two hours at normal operating conditions without

any indication of malfunction, it should be allowed to operate

over-night on automatic controls. Then a thorough recheckof the entire system operation should be made as follows:

a. Compressor manufacturer model and serial number.

b. Equipment manufacturer model and serial number.

c. Design operating temperatures.

d. Refrigerant and weight of charge.

e. Electrical service, volts, cycles, phase, wire size.

f. Control circuit, voltage, breaker size.

g. Contactor or starter, manufacturer, model, size, part

number.

h. Compressor motor protection(if available), type, size,

part number.

i. Data on relays or other electrical components.

j. Pressure control, type, size, model number, setting.

k. Data on miscellaneous components such as pressure

controls, crankcase heaters, solenoids, valves, etc.

l. Liquid line drier, manufacturer, size, model number,

connections.

m. Schematic diagram of refrigerant piping.

n. Final settings on all pressure, regulating and safety

controls.

o. Microprocessor details

a. Check compressor head and suctionpressures. If not within system design limits,

determine why and take corrective action.

b. Check liquid line sight glass and expansion

valve operation. If there are indications that

more refrigerant is required, leak test allconnections and system components and

repair any leaks before adding refrigerant.

c. When applicable, observe oil level in

compressor crankcase sight glass, and addoil as necessary to bring level to center of

the sight glass.

d. Thermostatic expansion valves must be

checked for proper superheat settings.Sensing bulbs must be in positive contact with

the suction line. Valves with high superheat

settings produce little refrigeration and poor

oil return. Too little superheat causes low

refrigeration capacity and promotes liquid

slugging and compressor bearing washout.

Liquid refrigerant must be prevented from

reaching the crankcase. If proper control

cannot be achieved with the system in normaloperation, a suction accumulator must be

installed in the suction line just a head of the

compressor to prevent liquid refrigerant from

reaching the compressor.

e. Using suitable instruments, carefullycheck line voltage and amperage at the

compressor terminals. If high or low voltage

indicated, notify the power company. The

current normally should not exceed 120%

of the nameplate rating. If amperage draw

is excessive, immediately determine the

cause and take corrective action. On three

phase motor-compressors, check to see that

a balanced load is drown by each phase.

f. All fan motors on air cooled condensers,

evaporators, etc should be checked for

proper rotation. Fan motor mounts should

be carefully checked for tightness and properalignment. If belt drives are used, check the

belt tension. All motors requiring lubrication

should be oiled or greased as necessary.

Service Record

A permanent data sheet should be prepared on each

installation, with a copy for the owner and the original for the

installing contractors files. If any other firms are to handle

service and maintenance, additional copies should be prepared

as necessary.The form of the data sheet may vary, but a complete record

of sizes and identification of all components used in theinstallation, together with any pertinent information should be

included. Following is suggested check-off list:


19/65 | 19

OPERATION

Unit Start Up

Sequence of OperationThe unit may be enabled or disabled through the Run/

Stop toggle switch in the unit mounted control panel or

from the room unit on/off button. Control is based on room

temperature sensed by room unit(for units with duct sensor

,control is based on duct temp). Evaporator fan motor

starts first. Compressors will be staged based on the set

point and actual room temperature. On an increase inroom temperature, cooling stages will be added and

on a decrease in room temperature, cooling stages

will be removed from the system. Sequence for the

compressors and motors are as given below:

Switch on the three phase power supply to the unit.

Switch on the control circuit breakers. Unit controller

will start up.

Check for any alarms in the controller. If there are

any alarms, correct the cause and clear them.

Turn on the Run/Stop toggle switch in the unit

control panel.

Press the power button in the room unit. Then

supply fan will start.

Make sure the refrigerant circuits are enabled in

the relevant circuit screen in the controller display.

Compressors will start based on the temperature setpoint set in the room unit and the indoor temperature.

Make sure that the unit is in cooling mode, which

can be selected from the room unit.

Condenser fans will start with compressors and will

cycle based on discharge pressure.

Supply FanSupply fan will be switched on if the belowconditions are satisfied.

Controller start up is finished.

Run/Stop switch in the unit controlpanel is ON.

Room unit power icon is ON.

Room unit schedule is ON (If schedule is

disabled, then unit will run continuously)

Communication between unit controller

and room unit is healthy.

Motor overload is healthy.

Voltage Monitor is healthy.

Supply fan has two modes; ON (continuouslyON) or AUTO (ON when there is cooling or

heating demand).

Compressor

Compressor will switch on if the below conditions

are satisfied.

Compressor minimum OFF time

completed.

Supply fan runs for 30 seconds.

Circuit enable (from controller display)

is enabled. Unit is in cool mode.

Demand for compressor is present.

Discharge pressure and motor protector

module (if available in compressor) are healthy.

If above are satisfied, solenoid valve will be opened

and when the low pressure switch closes, compressor

will be started.

A typical two compressor control is as shown below:

Condenser fans

Condenser fans will switch on with associated compressor(s)

and cycle based on discharge pressure.

For single compressor units or units with circuits having

independent condenser fans, condenser fans will be

switched on based on the discharge pressure of that

circuit. Each fan will switch on if pressure is above the

stage on value and will switch of if the pressure is below

stage off value.

For units with more than one compressor sharing the

condenser fans, the highest pressure among the circuits

will be taken to cycle the fans.

Unit Control ler Display and Keypad

The keypad/display of the controller consists of a 64 x 144 screen

resolution 5 line 22 character display screen,3 buttons and a push

& turn knob for navigation.

Buttons

Info button: This is used to enter the unit information screen

where the SKM Unit model & serial number can be viewed.Alarm but ton: This is used to enter directly the alarm screen for

viewing the alarm details & to reset them manually if required.

Esc button:This is a back button to move back to the previous

screen or to the home screen.

Push & Turn Knob

This is a navigation wheel that can be rotated as well as pushed.

Rotating the wheel navigates between the lines of the screenand also to change/edit the changeable values on the screen.

Clockwise rotation increases the values and anti-clockwise rotation

decreases the value. Pushing the wheel acts as an Enter button

to acknowledge the changed value.


20/65 20 |

OPERATION

If supply fan is not starting, navigate to these screens to find out

the reason. In order for the supply fan to start, the Run/Stop input

should be Run, Room Unit should be On, Schedule Status

should be On in case the schedule is enabled, Motor over load

should be healthy and Voltage monitor should be healthy.

Circuit ScreenEach circuit screen will show the status of all the inputs and

outputs related to that circuit.

These will show the status of supply fan motor (On or Off), Circuit

enable/disable selection, Unit mode (Cool, Heat, Auto or Vent),

Discharge pressure (Healthy or Trip), Suction pressure (Healthy

or Trip), compressor motor protectors if available (Healthy or

Trip), compressors (On or Off) and liquid line solenoid valve

(Open or Closed).

Note that circuit can be enabled or disabled from the controller

display itself. In order to do that, highlight the Circuit Enable line

and then press the navigation wheel. Then rotate the navigation

wheel in order to enable or disable the circuit and then press

the wheel.

Unit operating mode selection is from the Room unit.

Condenser fans

These screens will show the discharge pressures of each circuit

and status of the condenser fans.

Schedule

The schedule screen will allow setting the On time and Off time

for each day of the week. If the schedule is enabled, then unit

will work based on this schedule only.

Set poin ts

This screen will show the temperature set point and actual indoor

temperature (or duct temperature if optional duct sensor is used).

If factory password is entered, then set points screen will show

access to factory parameters as well.

The main displayscreen consists of a5 line display, with

the first linedisplayingthe page title and a numeric display

of the number ofalarms along with the symbol if any

alarmsare present. Second& third lines display the date &

time respectively. There arethreesubmenus inthe display

namely, SYSTEMOVERVIEW, PASSWORD &ALARMS.

Everypagecan consist of data fields, eitherchangeable or with

information only. As the cursormoves over each line, thetext

in thelineis highlighted with ablackbox around it and the text

turning white. As thenavigation wheel is rotated thesubsequent

lines get highlighted witha black box around them. When a line

consists of anarrow in the far rightof the page, it isreferred to as

amenu group. When the navigation wheel ispushed, the display

goesto a new page consisting of thesubmenus. Thetitleof the

menu group appears as the title of the new page.

Figure:Rotation of the navigation wheel

Figure: Pushing the navigation wheel

The system overview menu consists of information on

thesupply fan, circuits, condenserfans, andset points.

These submenus give more information on the unit

including safeties and status of compressors, motors

and setpoints. Different screensof thecontrollerare

as given below.

Main ScreenThis screen will show date & time,system over view,

password & alarms.

SystemOverviewSelecting thesystem overviewwill lead tobelow

screens

Fromthe abovetwo screens, further navigation

is possible to different screenswhich will giveinformation about supply fan,each refrigerant

circuit, condenser fans, schedule and set points.

Supply fan

Thebelow screens will give information about all

theinputs andoutputs relatedto supply fan.

Display and Keypad operation

.


21/65 | 21

OPERATION

Factory parameters will show Compressor Minimum offtime, Compressor Minimum On time, Low pressure alarm

delay, Cooling step, Cooling Differential, Condenser Stage1

On pressure, Condenser Stage1 Off pressure, Condenser

On Differential pressure, Condenser Off Differential pressure,

Schedule enable/disable, Clearing alarm history and software

BSP version of the controller.

Note that factory parameters should be changed only by SKM.

Unit InformationThis screen will provide the information about the unit model

name and SKM serial number.

Alarms

This screen will show alarm list and alarm history.

Pressing the alarm list will show all the active

alarms. All alarms will be with date & time and will

be in easily readable English language.

Note that some of the alarms (like high

discharge pressure) are manual reset. In orderto acknowledge the manual reset alarms, follow

below steps.

Below Screen will appear.

Rotate the Navigation wheel and then screen will show

Exe...

Press the navigation wheel and all the alarms which are

not active will get reset.

List of Alarms in the Unit Controller

Below are the various alarms configured in the Unit controller.

Supply Fan Motor: Trip

This alarm occurs when the overload of supply fan motor detects

an overload condition in the motor. When this alarm happens,

entire unit will be switched off. This alarm is auto reset as standard.

Voltage Monitor: Trip

This alarm occurs when the voltage monitor connected in the

main incomer detects an under voltage or over voltage or phase

reversal or phase imbalance or single phasing condition. Whenthis alarm happens, entire unit will be switched off. This alarm is

auto reset as standard.

Room Unit Communication: Lost

This alarm occurs when the unit controller looses communication

with the room unit. When this alarm happens, entire unit will be

switched off. This alarm is auto reset as standard.

Circuit-# Suction Pressure: Trip

This alarm occurs when the low pressure switch senses a low

suction pressure in the refrigerant circuit. This alarm will be

generated, if one refrigerant circuit is On for cooling demand

and the low pressure switch doesnt close for a specific time (low

pressure alarm delay set point). When this happens, corresponding

circuit will be switched off and alarm will be generated. This alarm

is automatic reset as standard.

Circuit-# Discharge Pressure: Trip

This alarm occurs when the high pressure switch senses a

high discharge pressure in the refrigerant circuit. This alarm

will be generated, if the high pressure switch remains open for

one second. When this happens, corresponding circuit will be

switched off and alarm will be generated. This alarm is manual

reset as standard.

Compressor-# Motor Protector: Trip

This alarm will be generated only for those compressors with a

built in electronic motor protector module. It occurs when the motor

Enter the user password 1234 (Refer

Passwords)

Go to alarm list screen and press

acknowledge


22/65 22 |

OPERATION

If the room unit address is not set correctly, it will display as

below (P- - blinking).

Passwords

In order to enter the password, use Password screen.Follow the below steps.

Go to the Password screen in the Main Menu.

Use the navigation wheel to enter password

(Rotate to change and Press to select.). If user

password is required, enter 1234.

Once the password is entered, a number

corresponding to the password level will

appear on left top of the screen. For user

password, it will be 4.

Operation of the Room Unit

The room unit displays indoor temperature (duct temperature if

optional duct sensor is used), temperature set point, unit on/off

status, unit operating mode, fan mode, day of the week, time of

the day and schedule. Room unit will let the user to make the

unit on/off, change the operating mode, change the fan mode,adjust the set point, change the temperature measurement unit,

change date & time and operating schedule.

Adjust the set point, change the temperature measurement unit,

change date & time and operating schedule.

Press power button, mode button, minus button and

plus button simultaneously as shown below.

Setting the address in Room Unit

Room unit will display the software version as below.

Press mode button; room unit will display parameter 001

as below, with 001 blinking

22 |

asswor s

In order to enter the password, use Password screen.Follow the below steps.

Go to the Password screen in the Main Menu.

wordUse the navi ation wheel to enter ass

(Rotate to change and Press to select.). If user

password is required, enter 1234.

Once the password is entered, a number

corresponding to the password level will

appear on left top of the screen. For user

password, it will be 4.

Power Button

Minus Button

Mode Button

Plus Button

protector module senses a high internal temperature

in the compressor. When this happens, corresponding

circuit will be switched off and alarm will be generated.

This alarm is automatic reset as standard.


23/65 | 23

OPERATION

Press plus button multiple times to reach

parameter 005. At this stage parameter 005

will be blinking. On pressing mode button;

parameter value will start blinking. Use plus

button or minus button to make it 005 as

shown below (if it is already 0005, no need

to do this step). Press mode button again,

then parameter 005 will start blinking.

Press plus button to reach parameter 006.

At this stage parameter 006 will be blinking.

Press mode button and then use plus

button or minus button to make the value

0002 (if it is already 0002, no need to do

this step). Press mode button again, then

parameter 006 will start blinking.

Press plus button to reach parameter 007. At

this stage parameter 007 will be blinking. Press

mode button and then use plus button or

minus button to make the value 0003 (if it is

already 0003, no need to do this step). Press

mode button again, then parameter 007 will

start blinking.

Press plus button multiple times to get back

to parameter 001. Then press power button,

the version screen will be displayed.

Press power button again, then room unit

will show normal display as below.

Switching on and switching off the unit

Press the button to make the unit on and off. When the unit is

on, will be shown on the display.

Changing the Unit operating mode

Operating mode of the unit can be changed by pressing button.There are two modes for cooling only units and four modes for

units with electric heater. The modes are cool ( ), heat ( ),

auto cool-heat ( ) and Vent ( ). Note that in vent mode,

compressors or heaters ( if available ) will not operate.

Changing the fan operating mode

Operating mode of the fan can be changed by pressing the button.

There are two modes for the fan which are Auto ( ) and On ( ).

Auto means the supply fan will run only when there is cooling or

heating demand. On means supply fan will run continuously. Inthe units where there is much changes in temperature, always

use On mode.

Changing the Set poin t in Room Unit

Press + and - buttons to adjust the temperature set point.

Changing the Temperature display un it

Long press the button to toggle the temperature display unitbetween oCelsius and oFahrenheit.

Alarm Indication

In case if there is any alarm present in the unit, will blink onthe room unit display. Once the alarms are cleared from the unit

controller, then the alarm symbol will disappear.

Time and Day of the week

Room unit will show the time in 12 hour format and the day of

the week. Day of the week will be 1 for Monday, 2 for Tuesday,

3 for Wednesday, 4 for Thursday, 5 for Friday, 6 for Saturday

and 7 for Sunday.

Time and Date Setting

By pressing the button, user will enter time and date setting.

Pressing + or -button can change the variables those are

blinking on the screen, while pressing button will confirm the

changes and the cursor will move to the next variable automatically.

The first view is time setting, user can change 3 items: hour,minute and time for-mat. The view is showed as follows:

Firstly the hour area will be blinking; pressing + or - canchange the number of hour, pressing will confirm the changes

and the cursor will move to the minute area automatically.

After the number of minute is confirmed, the whole time areawill blink. Pressing + or -button will switch time format

between 12-hour with AM/PM and 24-hour. It will shows as

)


24/65 24 |

OPERATION

After the year is confirmed, it will jump to the view of month

and day. The view is showed as follows:

After the month and day is confirmed, HMI-SG will return

to the view of time. Press button PROG or there is no any

operation for 1 minute, it will exit the setting.

follows in 24-hour time format:

After the time format is confirmed, HMI-SG will jumpto the view of year. It will show as follows:

ENTER PASSWORD

ENTRY ****

CIRCUIT-1SUPPLYFAN MOTOR : OFF

CIRCUIT1 ENABLE : ENABLE

UNIT MODE : VENT

DISCH.PRES.-1 : TRIP

SUCT.PRES-1 : HEALTHY

COMPRESSOR-1 : OFF

SOL.VALVE-1 : CLOSED

SUPPLY FAN

RUN/STOP INPUT : STOP

ROOM UNIT : ON

ON/OFF SCHEDULE : ENABLE

SCHEDULE STATUS : ON

FAN MODE : ON

MOTOR OVERLOAD : TRIP

VOLTAGE MONITOR : TRIP

SUPPLY FAN MOTOR : OFF

CIRCUIT-2

SUPPLYFAN MOTOR : OFF

CIRCUIT2 ENABLE : ENABLE

UNIT MODE : VENT

DISCH.PRES.-2 : TRIP

SUCT.PRES-2 : HEALTHY

COMPRESSOR-2 : OFF

SOL.VALVE-2 : CLOSED

CONDENSER FANS

DISCH.PRES.-1 : XX.X PSI

DISCH.PRES.-2 : XX.X PSI

_____________________________FAN-1 : OFF

FAN-2 : OFF

FAN-3 : OFF

FAN-4 : OFF

SCHEDULE

MONDAY:

SCHEDULE-1: HH: MM-HH:MM

TUESDAY:


WEDNESDAY:


THURSDAY:


FRIDAY:


SATURDAY:


SUNDAY:


MAIN MENU

DATE

TIME

SYSTEM OVERVIEW

PASSWORD

ALARMS

SYSTEM OVERVIEW

SUPPLY FAN

CIRCUIT-1

CIRCUIT-2

CONDENSER FANS

SCHEDULE

SETPOINTS

HMI PASSWORDENTER PASSWORD

CLOSE ACCOUNT

ALARMS

ALARMLIST

ALARMHISTORY

FACTORY SETTINGS

COMP.MIN.OFF TIME : XXX s

COMP.MIN.ON TIME : XXX s

LP ALARM DELAY : XXX s

COOLING STEP : XX.X C

COOLING DIFF. : XX.X C

COND.STG1 ON : XXX PSI

COND.STG1 OFF : XXX PSI

COND.DIFF.ON : XXX PSI

COND.DIFF.OFF : XXX PSI

ON/OFF SCHEDULE : Enable

SETPOINTS

TEMP.SETPOINT : XX.X C

: XX.X C

FACTORY SETTINGS

BSP VERSION

CLEAR ALM HIST

: X.XX: PASSIVE

INDOOR TEMP

An Overview Of Menu Structure


25/65 | 25

OPERATION

Table 5


26/65 26 |

MAINTENANCE

26 |

Periodic MaintenanceFollowing Checklist describes the suggested maintenance schedule to maintain proper operation of the unit. Detailed

procedures are mentioned in the corresponding pages.

The above mentioned schedule is typical and will vary largely based on si te conditions.

Table 6

Component Checkl ist Weekly Month ly Hal f Yearly Annual ly

EvaporatorFan/MotorSection

General Yes

Check for Corrosion andRepaint as Necessary

Yes

Check amperage draw onblower motor

Yes

Check condensate lineand clean if necessary

Yes

Check for correct voltageat unit

Yes

Motors General Check Yes

Check for unusual noisefrom the motor

Yes

Check all wiring for loose

connectionsYes

Filter SectionAir filter to be washed &cleaned

Yes

Evaporator CoilSection

Check for Debris /Blockage over fins & cleancoil if necessary

Yes

Check connecting lines,joints & coil for evidenceof oil leaks

Yes

Operation LevelMaintenance

Oil Level at Sight Glass Yes

Superheat at Compressor Yes

Crank Case HeaterOperation

Yes

Refrigerant Sub cooling inLiquid Line

Yes

Operating Pressures Yes

Control Panel

Dust & Debris on PowerTerminals/ Contactors/Loose Cable Lugs

Yes

Check for correct voltageat unit (Unit operating)

Yes

Check Unit Operation Yes

Check for alarms in UnitMicroprocessor

Yes

Condenser Fan& Motor

Check for Vibrations &Noise

Yes

Check unbalance of theFan

Yes

Motor Bearings to bechecked

Yes

Corrosion Yes

Fan Blades to be checked/Balancing

Yes

Condenser CoilSection

Check connecting lines ,joints & coil for evidenceof oil leaks

Yes

Clean & inspect outdoorcoil , wash with water ifnecessary

Yes


27/65 | 27

MAINTENANCE

Never use oxygen fo r pressurizing a

system; an explosion may occur if oil

is present in the system. Always use

a gauge equipped pressure regulator

on the high pressure back-up gas, and never

interconnect the refrigerant cylinder and the

inert gas cylinder through a gauge manifold.

Nitrogen and carbon dioxide cylinder pressures

can rupture a refrigerant cylinder.

6.Apply heat evenly over the length and circumference of thejoint to draw the brazing material into the joint by capillaryaction. Remove the brazing rod and flame from the joint assoon as a complete fillet is formed to avoid possible restriction

in the line.

7. Visually inspect the connection after brazing to locate anypin holes or crevices in the joint .

Never solder, braze or weld on

refrigerant lines or any unit

components with pressures that are

above atmospheric pressure or where

refrigerant may be present. Always remove

refrigerant by following the local guidelines.

Af ter ref rigerant removal, use dry ni trogen to

bring system back to atmospheric pressure

before opening system for repairs. Mixtures of

refrigerants and air under pressure may become

combustible in the presence of an ignition sourceleading to an explosion. Excessive heat from

soldering, brazing or welding with refrigerant

vapours present can form highly toxic gases

Failure to follow all proper safe refrigerant

handling practices could result in death or

serious injury!

Maintenance

The maintenance of this equipment shall be in accordance

with the regulation of authorities having jurisdiction and

all applicable codes. It is the responsibility of the installer

to determine and follow the applicable codes. Low head

pressure may lead to poor, erratic refrigerant feed control at

the thermostatic expansion valve. The units have automatic

control of the condenser fans which should provide adequate

head pressure control down to 50 F (10 C) provided the

unit is not exposed to windy conditions. The system design isresponsible for assuring the condensing section is not exposed

to excessive wind or air recirculation.

ProceduresIt is quite probable that a majority of operating failures can be

traced to careless or inadequate maintenance procedures. The

following instructions have been prepared to help the service

engineer systematically cover the many points which must

be considered to provide each installation with trouble freeperformance.

Take extreme care to keep refrigeration tubing clean and

dry prior to installation. The following procedures should be

followed:

Brazing Procedures

1. When copper is heated in the presence of air,Copper oxide forms. To prevent copper oxide fromforming inside the tubing during brazing, an inert gas

should be passed through the line at low pressure

to prevent scaling and oxidation inside the tubing.

Dry nitrogen is preferred. Nitrogen displaces air

in the tubing and prevents oxidation of the interior

surfaces. A pressure regulating valve is to be usedto control the flow.

2. Ensure that the tubing surfaces to be brazedare clean, reaming at the ends of tubes isto be done to remove any burrs and keep the

surface even.

3. Make sure the inner and outer tubesof the joint are symmetrical and have aclose clearance, providing an easy slip fit. If

the joint is too loose, the tensile strength of

the connection will be significantly reduced.

The overlap distance should be equal to the

diameter of the inner tube.

4. Wrap the body of each refrigerant linecomponent like expansion valve, solenoidvalve, Hot gas bypass with a wet cloth to keep

it cool during brazing. Move any tube entrance

grommets away for the brazing area.

5. Flux , when used is to be applied in smallquantities only. Excessive flux, when used,can enter the system and contaminate the

refrigerant system.

7/24/2019 7.Installation,Operation & M

7.installation,operation & maintenance(iom)

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