049

March, 1981SupersedesPE-G2Dated Dec., 7975PE-G3Dated Oct., 1976

Westinghouse Electric CorporationCommercial-IndustrialAir Conditioning DivisionStaunton, Virginia 24401

OPERATION MANUAL

PE - 606310791160

Models PE 15OW 55OWPE 063/079/100Top MountedCompressor Units Only

- COMPRESSOR NAMEPLATE

MAIN UNITNAMEPLATE

ANDSHOP ORDER NO

Operation &

Maintenance

Manual

CONDENSER NAMEPLATE

EVAPORATOR NAMEPLATE

OPERATION

APPLICATION

The operation and maintenance procedures coveredin this publication apply to model PE (hermetic motor)and PG (open motor drive) units of the compressorsizes indicated throughout the literature. Open driveunits require additional operation and maintenanceinspections related to motor bearing lubrication cou-pling and shaft alignment. For coupling and shaftalignment, see Bulletin PE-G10. For motor mainte-nance, see the instructions for service provided by themotor manufacturer.

I. CONTROL CENTER

The control center contains all of the necessaryprotective and operating controls, (less water flowinterlocks). These include the cycling thermostat, theGuardistor protective circuit,SurgegardTM, high andlow pressure cutouts, oil pressure protector, oil temp-erature cutout, vane closed switch, low pressureoverride, oil pump time delay, oil pump contactor,oil pump overload, capacitor, recycling timer, indicatorlights and relays, motor load and temperature module.The current design control center is subject to redesignand modification. If the unit control center is differentthan the one shown in Figure 2, see PE-G063/079/100supplement.

A. Controls

(For complete control summary, see Table 1.)

The function of operating controls is as follows:

Oil Pump Time Delay (OTD) -Set at 30 secondsto keep oil pump running for 30 seconds aftermachine has shut down.

Recycling Timer (TDR) -Set 40 minutes.Limits number of starts per hour (3 starts in 2hours).

Cycling Thermostat-C.T.W ill stop machine when the leaving water

reaches its set point in normal operation.

Vane Closed Switch-V.C.Prevents the machine from starting if the vanes

are not closed.

The control center is wired so that an indicating lightwill be energized upon the action of any of the safetycontrols. The light will remain on until such a time asthe control circuit is reset even though the cause ofcompressor shutdown has been corrected or hascorrected itself. Repeated trippings of any safetycontrol should be investigated by a qualified refriger-ation mechanic or Westinghouse service engineer. Thecontrol reset buttons are located on the outside of thecontrol center. Discharge, suction and oil pressuregauges are provided on the control center.

An interior view of the control center is shown in Fig.2.

B. Guardistor Protective Circuit

Positive protection against motor overheating is pro-vided with this unique Westinghouse motor develop-ment. The heart of the Guardistor protective circuit arethe thermistors, embedded in the motor windings,which sense motor temperature.

When the motor temperatures are normal, the therm-

TABLE 1 - OPERATING CONTROL SUMMARY

CONTROL SETTING S Y M B O L FUNCTION

HIGH PRESSURE CUTOUT* 150 PSIG H. P. Stop machine on excessive head pressureLOW PRESSURE CUTOUT* 26 PSIG L. P. Stop machine on excessive drop in suction pressure.

OIL PRESSURE SWITCH* 50 PSIG 0. D. Stop machine when oil pressure differential drops to 50 PSIG.

LOW PRESSURE OVERRIDE 28-31 PSIG L. P. 0. Closes vanes, on drop in suction pressure

OIL TEMPERATURE SWITCH” 14O’=F 0. T. Stop machine when oil temperature entering machine exceeds setting.

DISCHARGE TEMPERATURE SWITCH* 23O’=F H. T. Stop machine on rise in discharge temperatureVANE CLOSED SWITCH 30 PSIG v. c. Will not allow machine to start if the vanes are not closed to minimum

OIL PUMP TIMER 3 Minutes 0. P. T. Stops oil pump if machine fails to start.

RECYCLING TIMER 40 Minutes T. D. R. Limits number of starts of machine to 3 every 2 hours.

OIL PUMP TIME DELAY 30 Seconds 0. T. D. Keeps oil pump running for set time after machine stops

CYCLING THERMOSTAT Adjustable C. T. Stop machine when chiller leaving water reaches temperature below36F 9OF design condition

LOW OIL TEMPERATURE* 120° (Min.1 L. 0. T. Prevents compressor from starting with low oil temperature

SYSTEM MONITOR TIMER 1 Minute S.M. Lights system monitor light if machine does not start due to externalinterlocks or starter safeties.

SURGEGARD RELAY” _ S.G.R. Lights Surgegard light and shuts down machine if surge conditiondevelopes-check condenser water and tower condition.

*All safety switches that stop the machine require manual resetting before machine will restart

3

1.. Relay Base 12.2. O.P.T. Relay 13.3. Oil Pump Run Capacitor 14.4. Oil Pump Contactor 15.5. Transformer 16.6. Oil Pump Time Delay (OTD) 17.7. Anti Recycle Timer (TDR) 18.8. Relay115Volts(R1 thruR7) 19.9. Guardistor Relay 20.

10. Solid State Module 21.11. Low Oil Temperature Cutout 22.

Figure 2

P P

istor has low resistance which remains nearly constantup to predetermined critical temperature. At thistemperature, a sharp increase in resistance occurs for asmall increase in temperature. This sharp increase inresistance causes the Guardistor relay to drop outwhich in turn interrups the flow of current to theGuardistor reset relay causing it to become de-energized. When the Guardistor reset relay contactsopen, the MCR relay hold ing coi l becomes de-energized stopping the compressor.

A thermistor-equipped motor which utilizes the Guard-istor protective circuit integrates all heat causingfactors of load, ambient, and power supply in themotor windings to give you greatly increased protec-tion against motor burnout.

The Guardistor control is a manual reset protective

VANE SPEEDADJUSTMEN

r-OPEN

J CL

Oil Pressure GaugeDischarge Pressure GaugeEvaporator Pressure GaugeOil Pump Motor OverloadHigh Pressure SwitchCycling ThermostatLow Pressure OverrideSurgegard RelayHigh Oil Temperature ThermostatLow Pressure SwitchSystem Monitor Timer

)SE

device. The reset button is provided on the controlcenter. THE CONTROL CIRCUIT MUST BE RESETIN THE EVENT OF A POWER FAILURE ORWHENEVER THE CONTROL VOLTAGE SOURCEIS INTERRUPTED.

C. SurgegardTM

Westinghouse currently uses a control device to sensethe occurance of a surge and stop the compressorbefore any damage can be sustained.

The Surgegard relay will prevent the compressor fromrestarting automatically until the malfunction can becorrected. Possible causes for a surge, or rotating stallcondition, may be dirty condenser tubes, coolingtower, pump, or control malfunction which acts toelevate the system’s head.

D. Solid State Capacity Control Figure 3

The Westinghouse solid state capacity control isdesigned to provide the temperature control andcurrent limit control in a single solid state package witha proportional type pulsing temperature control action.The control is provided with indicator lights and aquick disconnecting cable for replacement of the entiremodule in case of malfunction of its internal circuits.When the automatic temperature control is in opera-tion, the vane control solenoids are energized intermit-tently at a frequency which increases in intensity as thewater temperature departs from the set point until afull signal is maintained when the water temperature isapproximately 6OF or more away from the requiredtemperature. This action is designed to eliminate thesaw tooth operation of the conventional floating con-trol and should provide extremely stable temperaturecontrol when coupled with the needle valve vanespeed controls. The speed of the vane close operationis approximately one minute from full open to fullclose, and 3 to 5 minutes from full closed to fullopen.

A selector switch provides the operator with means formanual control in addition to the normal automaticoperation. Switch positions are:

Stop - this places the vanes in a stop position.Load - this energizes the load solenoid, moving the

vanes to an open position.

sketch Fig. 3.

Unload - this energizes the unload solenoid, mov-ing the vanes to a close position.

Automatic - this provides for automatic operationas described above.

2. Metering Valves

Indicator lights will function as follows: Red will lightduring the unloading control action; green will lightduring loading, and amber will light when the loadaction is overridden by the current limit control. Thislight will not light if the current limit acts while thecapacity control is in hold or unloading position.Current limit will override manual control.

1. Vane Operation

The needle metering valves in the oil drain lines areused to control the speed of vane travel while undertemperature control. The valves are factory-set so thatfrom a full close to full open position of the vanesrequires a minimum of 3 minutes. Maximum rate oftravel will be dictated by load requirements. Todecrease speed of travel, close the valve slightly.Speed should be slow enough to prevent over-controlling. At this rate of travel, the temperature canbe sensed and vanes stopped before a huntingsituation occurs. Vane speed can be adjusted throughaccess holes on the right hand side of the controlpanel.

The hydraulic system for the vane control operationconsists of a 4-way normally-open solenoid valve. Theaction of this solenoid valve controls the operation andposition of the vanes. Oil under pressure is supplied toeither or both sides of the piston depending upon whatsignal is being given by the electronic control.

E. Temperature Control

To open vanes, solenoid “SA” is de-energized and“SB” is energized allowing oil to flow from port C2 inthe solenoid valve to the piston and from the piston tothe drain through port Cl.

The temperature control has been calibrated at thefactory and should not need adjustment. Run theunit for several hours and check the leaving watertemperature against customer requirements. If cali-bration is required, operate the system by hand andobtain the proper condition.

To close vanes, “SB” is de-energized and “SA” isenergized allowing the oil to flow from port Cl to thepiston and draining from port C2.

When the vanes are in hold position, both solenoidcoils are de-energized putting full oil pressure on bothsides of the piston through both Cl and C2 ports. See

Because of the proportioning features of the temp-erature control, it will be necessary to have theselector switch in the hold position for at least 5minutes before calibration. (The thermal feedbackaction will cause an apparent and temporary shift inset point in the direction of the applied feedback orcontrol action. )

5

3. Set the temperature selector knob at the actualleaving water temperature. Switch the control toautomatic and immediately calibrate the tempera-ture control until both lights are out. One or theother of the lights will eventually begin to pulsebecause the dead band is less than .5F. However,the lights should never alternately pulse betweenload and unload unless the vanes are moving toofast.

F. Current Limit

1.

2.

3.

a

I I .

A 5.0 volt signal is required from the compressorstarter current transformer at full current. A 1 ohmresistance will provide 5.0 volts from a 5 amptransformer setting.

Set the current demand limit selector switch againstthe stop 100% and the current limit calibrationscrew fully counter-clockwise,

Start the system and place the selector switch inload position. When the full load current reachescustomer requirements, turn the current limit cali-bration clockwise until the amber light comes on.This places the control in current limit hold positionand insures that the unload action will be energizedif the current increases an additional 5%. Unloadthe machine and reload to R.L.A. (Rated LoadAmperage) and check calibration.

An alternate method of adjusting the motor loadcontrol is by allowing the motor to load to someamperage value below R. L.A.. Adjust the calibra-tion screw clockwise until the amber (hold) lightcomes on. At that point observe the amperage.Proceed by slowly adjusting the calibration screwcounter-clockwise until the amber light goes outand the green (load) light comes on. Allow themachine to load until the amber light again comeson. Again observe amperage. Continue this proce-dure until the full load amperage is reached. Whenthe 100% adjustment has been made, the 105% ismade simultaneously and no further adjustment isrequired.

LUBRICATION SYSTEM

The oil pump is completely self-contained in its ownreservoir. The assembly includes the pump, pumpmotor, oil heater and oil separator. The oil is pumpedthrough the oil discharge line, through a service valveto the shell and tube oil cooler, then to the 5-micron oilfilter in the compressor casting. The cooler serves adual purpose. It lowers the temperature of oil on startto prevent refrigerant flashing, and maintains proper oiltemperature under normal operating conditions. Thewater flow through the oil cooler must be adjustedwith the balancing valve so that the temperature of oilsupplied to the compressor bearings (leaving the oilcooler) is not less than 80°F nor more than 11O’F. Onsystems using chilled water for a cooling medium,

leaving oil temperatures should be on the low side ofthe acceptable temperature range when operating withthe coldest water. Long shutdown periods will producehigher than normal chilled water temperatures atstartup and will result in higher oil temperatures untilthe chilled water temperature is reduced.

Bearings are supplied with oil through internally drilledpassages. The oil drains from the bearings into thegear housing and returns to the oil pump through thescavenger line.

The oil pump also supplies the oil to the hydraulicpiston for positive positioning of the inlet guide vanes.Proper operation of the hydraulic system and bearinglube system can be maintained only if Westinghouserecommended oil is used. Westinghouse recommend-ed oils are 300 sus. viscosity (Suniso 4G or TexacoWF68) for PE063 and PE079, and 500 sus. eviscosity(Suniso 5G or Texaco WFIOO) for the PEIOO.

The quantity of oil charge for each machine is shownin the Physical Data, Section Xl.

The oil pump is equipped with an externally adjustablerelief valve - This valve should be adjusted tomaintain 100-110 Ibs. net oil pressure (100/110 Ibs.above suction pressure).

The heaters must remain on at all times the compres-sor is off. IN THE EVENT OF A POWER LOSS TOHEATER ALLOWING OIL TO COOL, THE OILHEATER SHOULD BE ENERGIZED A MINIMUM OF24 HOURS PRIOR TO THE TIME COMPRESSORIS STARTED. If the compressor has to start immedi-ately, oil should be drained and system recharged withfresh oil, which is free of refrigerant.

A low oil temperature thermostat in the control centerprevents starting the compressor with cold oil. Thisthermostat should be set as high as ambient conditionswill allow. This is an automatic reset device and whentripped, will cause the oil temperature light to glow.

There is also a heater in the gear case of thecompressor which maintains the proper heat in thegear case during the off period to insure proper oilreturn on start.

The oil filter should be changed after the first month ofoperation and annually thereafter.

Oil Safety

A spring-loaded piston and accumulator is incorpo-rated within the compressor to provide oil pressure tothe bearings, during spin-down, in the event of theloss of oil pressure.

6

Figure 4

1. Oil Cooler Water Connection In2. Oil Cooler Water Connection Out3. Oil Cooler4. Discharge Check Valve5. Discharge Victaulic Coupling6. Motor Cooling Line7. Guardistor Terminal Junction Box8. Motor Terminals

III. PRELIMINARY CHECKSBEFORE STARTING

Important

1.

2.

3.

4.

5.

Open all water valves to the condenser and seethat water flow is possible when the water pumpsare energized.

6.

Check that the actual line voltage is within theallowable plus or minus 10% of nameplate rating.

With the main disconnect switch in the “off”position, and the control circuit energized, makesure all linestarter contacts meet with even pres-sure and that all moving parts move freely. Checkthat the Fusetrons are in the circuit, that thecycling thermostat contacts are open and that theoff-on switch is in the “off” position.

7.

Check that the liquid shutoff valves are open. The(3) %” valves for discharge, suction, and oilpressure must be opened.

See that the oil pump has a proper supply of oil. 8.The oil should be visible in the sight glass. OIL INTHE SUMP SHOULD BE HOT- approximately130F to 140F. Assure oil pump valves are open.The front and the middle valves on the top of the 9.

7

9.. Motor Cooling Liquid Line Driers10. Hot gas by-pass thermostat11. Motor Cooling Liquid Line Shut Off Valve12. Main Expansion Valves13. Liquid Line Shut Off Valve14. Condenser Pressure Relief Valves15. Evaporator Pressure Relief Valve16. Hot Gas Bypass Valve.

oil sump should be opened fully, the back valve(closest to the unit going to the gear case) shouldbe open two turns from back seat.

Manually operate the condenser water-regulatingvalve (used on city water installations to clean thewater lines of sediment that accumulated duringinstallation. This will prevent the sediment fromdamaging the seat of the water-regulation valvewhen operating in an automatic position. When acooling tower is used, the HWR (condenser pump)relay should be energized when the compressorswitch is “on”. Flush the tower and piping beforestarting unit.

Check to make sure the compressor starter over-loads are filled with dash pot fluid if this typeoverload is used. See tag attached to overloads bystarter manufacturer for overload ratings. If starteris Star Delta the overloads are rated on phaseamps. DO NOT ATTEMPT FIELD CALIBRATIONOF OVERLOADS.

Check all pumps visually for proper rotation.Check evaporator and condenser water flow swit-ches for proper operation.

Check the power supply phase sequence.

10.

11.

12.

13.

IV.

A.

Check all electrical connections to make sure theyare tight. Serious difficulty could result from looseconnections. It is recommended all electrical con-nections be retightened prior to startup.

The oil cooler solenoid (SF) should energize at thesame time the oil pump is energized.

If all indicator lights are out and oil pumps fails tostart, check the following:

a.

b.

C.

d.

Recycling time (set at 40 minutes limit start perhour). CAUTION: Severe damage to the com-pressor can result if the anti recycle timer isturned to the Off position and the water flowinterlocks operate intermittently.

Interlocking devices

Oil pump-overload tripped.

Defective oil pump contactor, holding coil orcontacts.

If all the indicator lights are out, the oil pumpstarts and the MCR relay fails to energize, check:

a. Vane c losed swi tch (must be in c losedposition).

b. Oil pressure (must have minimum 50 PSIGdifferential).

c. Main starter overloads.

d. Condenser pump interlock.

e. Starter/control interlock wiring

PRESTART SYSTEM CHECK LIST

Unit

All service valves in operating positionControl circuit energized and oil heaters operating for24 hoursOil charge visible in sight glassAll safety switches interrupt M.C.R. operationOil cooler water balance adjusted to approximate flow,Proper flow through condenser and chiller. See A.D.100-20 8 A.D. 100-21 for water flow curves.

B. Electrical

Proper wire, breaker sizes and phase sequence (l-2-3)All wiring done as per Westinghouse diagramAll interlocks operating properlyAll pumps rotating in proper direction and lubricatedAll electrical connections tightAll starter parts move freely and contacts meet evenlyMotor overloads properly sized and filled with DashpotfluidAll load equipment operative and lubricated (fan coilunits, environmental equipment, process equipment)Recycling timer set to 40 minutes-Tower fan and controls operative (if applicable).

V. STARTING AND OPERATIONALCHECKS

A. Starting Sequence

When the 115 volt AC power supply is applied to thecontrol panel for the fist time or after an interruption incontrol voltage, the following will take place:

Both the oil sump heater and gear case heater will beenergized. With the compressor switch in an off posi-tion, no lights will be lit. When the switch is placed inthe “on” position, the oil pressure light will light. Bydepressing the reset button the lights will go out, andif an alarm circuit is used it too will be de-energized.

B. To Start The Machine

Start the chilled water pump. Place the compressorswitch in the “on” position.

W ith the system water temperature higher than thesetting of the cycling thermostat, the condenser waterpump starts. This closes the interlock circuit andallows the oil pump to start and energize oil coolerwater solenoid valve. When the oil pump develops thepressure required to close the oil differential switch (50Ibs. above suction pressure), it will close. If the vaneclosed switch is closed, it will energize the motorcontrol relay in the starter (MCR), and relay “R3”. Themachine will start. The vanes will be controlled byeither the electronic motor control (motor amps) or theelectronic temperature control (chilled water tempera-ture).

When and if the load drops below the minimum theunit can handle (approximately 10% of full load) theleaving water temperature will drop to the setting ofthe cycling thermostat and will open, stopping themachine. The oil pump will continue to run for 30seconds after the machine stops.

The machine can restart upon closing of the cyclingthermostat if the previous “on” cycle was greater than40 minutes. If the previous “on” cycle was less than 40minutes, it will be necessary for the remainder of the40 minutes to elapse before the machine can restart.This is determined by the T.D.R.

C. Operational Checks

1.

2.

Check the compressor and oil pump motor amper-age to make sure they are not in excess ofnameplate rating. The correct amperages are givenon the nameplates.

All accessories and controls should function accord-ing to requirements. If the performance of anyaccessories or any operational function appearabnormal, stop compressor and investigate themalfunction.

8

3. Check the operation of all the protective control tomake certain that each interrupts the control circuit.The correct settings for the controls are given inTable 1. Check the controls as follows:

a. High Pressure Cutout-Throttle the condenserwater supply slowly until reaching the cutoutpoint. Stop the compressor manually if the dis-charge pressure exceeds the correct cutoutsetting. Unit must be operating at 70% to 100%capacity to prevent a surge condition.

b. Low Pressure Switch--Low Pressure Override-Both switches can be checked simultanously byisolating the line going to the suction of thecontrol panel. Close the 3-way valve located onthe top of the evaporator to the right of the con-trol panel. Slowly bleed pressure off the linegoing to the control panel. Observe gauge pres-sure to determine trip point of the low pressurecutout. Low pressure override operation can bechecked using a voltmeter or ohmmeter at theterminals. LPO should close the vanes whensuction pressure drops below 32 to 28 psig.

c. Oil Pressure Protector- Manual ly Closethe differential pressure switch by holdingthe spring toward the front of the control.

d. Cycling Thermostat-Place a thermometer in theoutlet water of the chiller, the control can bechecked by slowly throttling the supply water tothe chiller. This will cause the outlet water temp-erature to drop. The reduction in water flowmust be done slowly enough for the ther-mometer to react to the temperature change. Ifa thermometer is not available in the outletwater, the control can be checked by placing thecontrol bulb in a container of water; by slowlyadding ice to the water, the operating point ofthe control can be reached. Observe tempera-ture on thermometer.

e. High Oil Temperature Control-To check theoperation, immerse sensing bulb in 150°F water.This should stop the compressor.

f. Check setting on recycling timer. It is set at 40minutes to limit compressor to 3 starts every twohours.

g. Overloads are calibrated and set by the startermanufacturer to trip at 105% of compressornameplate full load amperage.

h. Vane-Closed Switch-This switch is only func-tional until the machine starts. Before the ma-chine starts, manually open the switch. After theoil pressure switch has closed, the machine willremain off until the vane closed switch, which ismanually held open, is closed.

i. See that the oil pressure protector is set toapproximately 50 PSIG differential.

4.

5.

6.

Several causes for frequent complaints are listedbelow:

a.

b.

C.

d.

e.

f.

g.

h.

Air in water circuit or vessel

Inadequate quantity of water (check pressuredrop through chiller and condenser). See AD100-20 and AD 100-21 for vessel pressure drops.

Water pump not functioning properly

Plugged water strainer

Lack of head pressure control

O p e r a t i o n a t l o w e r t h a n d e s i g n w a t e rtemperature

Inadequate air over cooling coils

Lack of low side load-operating with only aportion of air units installed or operating.

Record complete set of operating data for futureusage.

Instruct the owner on proper operation and care ofthe system.

CAUTION: The disconnect switch for control cir-cuit (furnished by contractors) must be left on at alltimes in order to maintain operation of the oil andcompressor heaters. The control center selectorswitch can be turned to the “off” position at suchtimes that compressor operation is not desired.

D. Shutdown

The sequence in a normal shutdown is as follows.Upon placing the compressor switch in the “off”position, the condenser pump relay is de-energized,and the MCR relay drops out. The compressor and oilpump heaters come on and the oil pump continues torun for 30 seconds, after the machine has stopped, atwhich t ime the oi l cooler solenoid (S.F.) is de-energized.

If the unit is stopped by a safety, the sequence is thesame as a normal shutdown plus the appropriateindicator light becomes energized. The machine willstop and remain off until the reset is pushed, even ifthe cause of the outage has corrected itself.

When the machine is stopped by a current interruptionor the tripping of the oil pump overload, oil (fromaccumulator) will be supplied to the bearings for thespin-down period by the action of a spring-loadedpiston which forces oil through the oil passages. Thus,the machine has oil pressure on all shutdowns, even ifthere has been a power failure.

9

MAINTENANCE

VI. ROUTINE MAINTENANCE

A. Lubrication

After the system is once placed into operation, noadditional oil is required except in the event that repairwork becomes necessary to the oil pump or unless alarge amount of oil is lost from the system due to aleak.

The oil system can be isolated to service any oil pumpcomponent or IGV (inlet guide vanes) solenoid system.

To isolate the inlet guide vane system, it is onlynecessary to backseat the service valve on the oilpump (the one with the XI” line) and close the supplyvalve (on the oil filter). Relieve the pressure slowly; andthe inlet guide vane solenoids, oil pressure switch andoil pressure gauge can then be serviced.

B. Changing Oil Filters

Close the supply valve on the oil filter cavity on CEO79and CE100 compressors. On CEO63 compressors, closethe discharge valve on the oil pump pot. Relieve thepressure on the oil filter housing line by purging slowly.When all the pressure has been vented, remove thefilter cover and replace core. When reassembling, ventas much air as possible from the oil lines before placingthe machine back into operation. Westinghouse rec-ommends the oil filter be changed annually.

C. Refrigerant Cycle

Maintenance of the refrigerant cycle consists of main-taining a log of the operating conditions, and assuringthe unit has the proper oil and refrigerant charge.

At every inspection, the oil, suction and dischargepressures should be noted and recorded, along withcondenser and chiller water temperatures. Assumingwater flow is correct, this confirms correct refrigerantcharge. Correct suction pressure will be indicated byreference to past suction readings on the same unit.

The suction line temperature at the compressor shouldbe taken at least once a year. Subtracting from this,the saturated temperature equivalent of the suctionpressure will give the superheat. Extreme changes insuperheat over a period of time will indicate possibledeterioration of the expansion valves. Proper superheatsetting is 2-6OF at full load.

The factory oil charge, supplied with the compressor,is adequate for the system. Normal oil charge isindicated by an oil level visible in the oil reservoir sightglass.

D. Electrical System

Maintenance of the electrical system involves thegeneral requirement of keeping contacts clean andconnections tight and checking on specific items asfollows:

1.

2.

3.

The compressor current draw should be checkedand compared to nameplate value. Normally theactual current will be lower since the nameplaterating represents full load operation. Also check allpump and fan motor amperages and compare withnameplate ratings.

Inspection should verify that the oil heaters areoperative. The heaters are insert cartridge type andcan be checked by ammeter reading. They shouldbe energized whenever power is available to thecontrol circuit (whenever compressor is inopera-tive). When the compressor starts the heaters arede-energized.

At lease once a year, all safety controls exceptcompressor overloads should be made to operateand their operating point checked. Any control mayshift its operating point as it ages, and this must bedetected so the controls can be readjusted orreplaced. The compressor overload relays are asafety control, but to force a compressor load totrip them may cause more trouble than it saves.Purnp interlocks and flow switches should bechecked to assure the interrupt control circuit whentripped.

4

5.

F

Contactors in the motor starter should be inspectedand cleaned annually. Tighten all terminal connec-tions.

The compressor motor resistance to ground shouldbe checked and logged annually. This log will trackinsulation deterioration. Reading of 500,000 ohmsor less indicate insulation failure.

E.. Cleaning and Preserving

A common cause of service calls and equipmentmalfunction is dirt. This can be prevented with a littlemaintenance. The system components most subject todirt are:

Permanent or cleanable filters on the air handlingequipment must be washed in accordance with themanufacturer’s instructions; throwaway f i l tersshould be replaced. The frequency of this servicewi l l vary with each installation.

Remove and clean strainers in chilled water pump,oil cooler line and condenser water pump at everyinspection.

10

F. Westinghouse Maintenance Program

It is necessary that an air conditioning system receiveadequate maintenance if the full equipment life and fullsystem benefits are to be realized,

Followup Inspection-Maintenance should begin withan inspection of the system after 3 to 4 weeks ofnormal operation on a new installation.

Maintenance Contracts-Westinghouse offers a vari-ety of maintenance services through its NationwideService Organization. These contract services includeregular inspections and emergency service by factorytrained technicians. These services are availablearound the clock to keep your equipment running intop condition. With a Westinghouse Assured Mainte-nance contract, all parts, labor and materials arefurnished .with no additional cost to the customer.

It is widely recognized that a good maintenanceprogram is the essential first step in controlling energycosts. And through the Westinghouse Assured Main-tenance and Energy Management Program (W.A.M./E.M.) the owner is assisted in establishing a compre-hensive Energy Management plan to meet his needs.For further information concerning the many servicesavailable, contact your local Westinghouse ServiceRepresentative.

VII. SEASONAL SERVICING

Prior to seasonal shutdown periods and before startingagain, the following service procedures should becompleted.

A. Annual Shutdown

Where freezing temperatures may be encountered,the condenser and chiller water piping should bedisconnected from the supply and drained of allwater. Dry air blown through the condenser will aidin forcing all water out. Removal of condenserheads is also recommended. The condenser andevaporator are not self-draining. Water permittedto remain in the piping and vessels will rupturethese parts if subjected to freezing temperatures.FORCED C IRCULAT ION OF ANTIFREEZETHROUGH THE WATER CIRCUITS IS THEONLY SURE METHOD OF AVOIDINGTROUBLE.

Take measures to prevent the shutoff valve in thewater supply line from being accidently turned on.

If a cooling tower is used and if the water pump willbe exposed to freezing temperatures, be sure toremove the pump drain plug and leave it out so thatany water which may accumulate will drain away.

Open compressor disconnect switch, and removeFusetrons. If transformer is used for control vol-tage, disconnect must remain on to provide power

5.

to oil heater. Set compressor switch to “off”position. To insure against the possibility of anaccidental start, remove relay Rl.

Check for corrosion and clean and paint rustedsurfaces.

B. Annual Startup

A dangerous condition can exist if power is applied toa faulty compressor motor stator which has beenburned out. This condition can exist without theknowledge of the man starting the equipment.This is a good time to check the motor windingresistance to ground. Annual checking and recordingof this resistance will provide a record of any deteriora-tion of the winding insulation. All new units have wellover 100 megohms resistance between any motorterminal and ground. Whenever great discrepancies inreadings occur or uniform readings of less than 5megohms are obtained, the motor cover should beremoved for inspection of the winding prior to startingthe unit. Uniform readings of less than 5 megohmsindicate motor failure is imminent and motor should bereplaced or repaired. Repair before failure occurs cansave a great deal of time and labor expanded in thecleanup of a system after a motor burnout.

1.

2.

3.

4.

5.

6.

7.

The control circuit should be energized at all times.If the control circuit has been off and oil is cool,drain and replace with fresh oil or allow 24 hours forheater to remove refrigerant from the oil beforestarting.

Check and tighten all electrical connections.

Replace the drain plug in cooling tower pump if itwas removed at shutdown time the previousseason.

Install Fusetrons in main disconnect switch (ifremoved).

Reconnect water lines and turn on supply water.Flush out condenser and check for leaks.

Clean and flush water tower for all units operatingon a water tower. Make sure tower “blowdown” orbleedoff is operating. Set up and use a goodmaintenance program to prevent “liming up” ofboth tower and condenser. It should be recognizedthat atmospheric air contains many contaminantswhich increases the need for proper water treat-ment. The use of untreated water may result incorrosion, erosion, sliming, scaling or alge forma-tion. It is recommended the service of a reliablewater treatment firm be obtained to determinewhat, if any, treatment is required-Westinghouseassumes no responsibility for the results of un-treated or improperly treated water.

Clean all surfaces and remove all litter. A clean unitis the sign of an good serviceman.

11

8. Refer to the procedures of “Preliminary ChecksBefore Starting” before energizing the compressorcircuit.

VIII. REPAIR OF SYSTEM

A. Pumping Down

If it becomes necessary to pump the system down,extreme care should be used to avoid damage to thewater chiller due to freezing. Always make sure thatfull water flow is maintained through the chillerwhile pumping down. To pump system down, closeall liquid line valves (1 to the motor cooling line, 1 t othe chiller). With all liquid line valves closed and waterflowing through chiller, start the compressor. In orderto pump system down as far as possible, it will benecessary to by-pass the low pressure override switchand jumper the Low Pressure cuttout. Set temperaturemodule to manual load position. Vanes must be openwhile pumping down to avoid a surge or other dam-aging condition.

Operate machine until the suction pressure stabilizes atapproximately 20-25 PSIG.

Stop the machine. Allow pressure to build up. Repeatthis procedure 3 times.

After the system has been pumped down, the gaspressure remaining will have to be purged before themachine can be serviced.

B. Pressure Testing

No pressure testing is necessary unless some damagewas incurred. After repairs are made, pressure test thesystem at a pressure that does not exceed the standbypressure in the condenser. (A test pressure higher thancondenser pressure would open the discharge checkvalve and allow flow of test pressure into condenser).In cases where the entire refrigerant charge is lost,follow the recommendations in the following para-graphs. The evacuation procedure can be followed inboth cases.

C. Leak Testing

In the case of loss of the entire refrigerant charge, theunit should be checked for leaks prior to charging thecomplete system. This can be done by charging onlyenough refrigerant into the system to build thepressure up to approximately 10 PSIG and addingsufficient dry nitrogen to bring the pressure up to amaximum of 125 PSIG and then leak test with a Halideor electronic leak detector. CAUTION: DO NOT USEO X Y G E N T O B U I L D U P P R E S S U R E A S ASERIOUS EXPLOSION CAN RESULT. A Pressure-regulating valve should always be used on the drumbeing used to build up the system pressure. Also, donot exceed the test pressure given above. When thetest pressure is reached, disconnect the gas cylinder.

If any leaks are found in welded or silver soldered jointsor if it is necessary to replace a gasket, relieve the testpressure in the system before proceeding. For copperjoints, silver solder is recommended.

After making any necessary repair, the system shouldbe evacuated as described below.

D. Evacuation

After it has been determined that there are norefrigerant leaks, the system should be evacuatedusing a vacuum pump with a capacity of approximately3 cu. ft/min. and that will reduce the vacuum to atleast 1 millimeter (1000 microns).

A mercury manometer, electronic or other type ofmicron gauge should be connected at the farthestpoint from the vacuum pump. For readings below 1millimeter, the electronic or other micron gauge shouldbe used.

The triple evacuation method is recommended and isparticularly helpful if the vacuum pump is unable toobtain the desired 1 millimeter of vacuum. The systemif first evacuated to approximately 29 inches ofmercury. Enough refrigerant vapor is then added to thesystem to bring the pressure up to zero pounds. Thenthe system is once again evacuated to approximately29 inches of mercury. This is repeated 3 times. Thefirst pull down will remove about 90% of the non-condensables, the second about 90% of that re-maining from the first pull down and after the third,only 1/ 10 of 1% non condensibles will remain.

E. Charging the System

PE water chillers are leak tested at the factory andshipped with the correct charge of refrigerant-12 asindicated on the unit nameplate. In the event the re-frigerant charge was lost due to shipping damage, thesystem should be charged as follows after first repair-ing any leaks and evacuating the system.

1.

2.

3.

4.

13

Connect the refrigerant drum to the gauge port onthe liquid shutoff valve and purge the charging linebetween the refrigerant cylinder and the valve.Then open the valve to the mid position.

Turn on both the cooling tower water pump andchilled water pump and allow water to circulatethrough the condenser and the chiller. (It will benecessary to manually close the condenser pumpstarter).

If the system is under a vacuum, stand therefrigerant drum with the connection up and openthe drum and break the vacuum with refrigerantgas.

W ith a system gas pressure higher than theequivalent of a freezing temperature, invert thecharging cylinder and elevate the drum above the

5.

condenser. With the drum in this position, valvesopen, water pumps operating, liquid refrigerant willflow into the condenser. Approximately 75% of thetotal requirement estimated for the unit can becharged in this manner.

After 75% of the required charge has entered thecondenser, reconnect the refrigerant drum andcharging line to the service valve on the chiller.Again, purge the connecting line, stand the drumwith the connection up and place the service valvein the open position.

Important

6.

7.

F.

At this point, the charging procedure should beinterrrupted and all prestart checks made beforeattempting to complete refrigerant charge. Com-pressor must not be started at this time. (Prelimi-nary check must first be completed). When allprestart checks have been made, remaining steps incharging procedure can be made.

After machine has been jogged and proper rotationhas been established make sure refrigerant shutoffvalves are open and that water is still circulatingthrough the chiller and condenser. Start the com-pressor by first closing the disconnect switch andthen place the control center selector switch in the“on” position, checking that (a) oil pump startsimmediately and voltage and amperage are normal,(b) compressor motor voltage and amperage arenormal and (c) that suction pressure and leavingwater temperatures are above freezing temperature.

To complete the refrigerant charge, allow refrig-erant to enter the system through the chargingvalve on chiller.

Both the temperature and pressure readings mustbe taken at full load conditions. Charge can bechecked by measuring the sub-cooling. It should be9OF to ll°F on units with a lOoFAT across thecondenser. On units with larger A’s, the subcoolingshould be increased accordingly. Superheat at fullload should be 2 to 4 degrees F.

Pressure Relief Valve Replacement

one of the relief valves is leaking on the two valve set,the following procedures should be followed:

If the valve closest to the valve stem is leaking, backseat the three-way valve all the way, closing the portto the leaking pressure relief valve. Remove and re-place the faulty relief valve. Reopen the three-wayshutoff valve to the mid position.

If the relief valve furthest from the valve stem isleaking, front seat the three-way valve and replace thevalve as stated above.

IX. OPERATIONAL CHECK LISTS

Operational Check

Suction, discharge and oil pressure normal.Proper superheat.Proper sub-cooling.Cutout points of all safety controls.Oil level.Oil temperature (90°Fm1 lOoF entering bearings).Voltage within tI 10%.Proper amperage for load conditions.Vane operation, manual &thermostatic control.Motor control 50% 100%.Interlocks interrupt operation.Recycling timer setting (40 min.).Cycling thermostat setting. (3-5’ below leaving

chilled water temp. )Check overloads (nameplate rating only).

System Checks

All motors checked - amps and volts.All pumps lubricated.All strainers cleaned - condenser pump, evap-

orator pump and oil cooler.All fans checked and filters on air handlers clean (if

applicable).All condensate drains clean.All motors lubricated.All belts adjusted and checked.All electrical connections tight, starter contacts,

starter movement.

Current condenser design uses two relief valves (1 set)separated by a three-way shutoff valve. In the event

13

X. Model and Vessel Code Interpretations

Model and Vessel Codes are subject to change, as more possible combinations become available.

Old Model Code Interpretation (Prior to Jan. 1981)

Model number PEO63KAQ2ORFO2GA2Digit number 1 2 3 4 5 6 7 8 9 10 11 12 1

-rIl-l---IT

Evaporator Size Code*Tube Type**

No. of Passes

Condenser Size Code”Tube Type””

No. of Passes

New Model Code Interpretation (Used after Jan. 1981)

Model number PE063JADigit number 1234561

T-T-Type Compressor #-Unit Size

Gear Ratio

H 2

15 16

I

7

OFEFOZEEAZ8 9 10 11 12 13 14

WrTVoltage

Evaporator Size Code’,Tube Type**

No. of Passes ICondenser Size Code*Tube Type””

No. of Passes

*See Vessel Code Interpretation for corresponding model number“““A” Type-High Efficiency Tube, “0” Type-Smooth I.D. Conventional Tube.#PE Units are Hermetic; PG Units are open motor drive.

14

XII - TROUBLE DIAGNOSIS CHART

Compressor Won’t Start No Lights Lit

POSSIBLE CAUSE

Compressor

Fuse Blown

POSSIBLE REASON

Grounded Wiring

Grounded MotorFuse Too Small

VERIFICATION

Check ConnectionsCheck Insulation

Megger MotorRefer to Elec. Data

REMEDY

Repair or Replace

Replace Stator if NecessaryInstall Proper Size

Control

FuseBlown

Grounded

Fuse Too SmallShorted

Check Circuit

Refer to Elec. DataCheck -Electrical

Components-Transformer

Contactor

Repair

Resize FuseReplace if Necessary

Replace if Necessan/

Low Pressure

Fouled Evaporator Tubes

Shortage of Refrigerant

Restricted Refrigerant Flow

Restricted Water Flow

Low Temperature Differential

Check for LeaksCheck Filter

Check Strainer

CleanRepair Leak-Add Ref.

Clean

Clean

OilPressure Oil Pump Off

Check Overloads

Check Voltage Relay

Check CapacitorsCheck MotorCheck Bearings

Reset

Replace if NecessaryReplace if NecessaryReplace if Necessary

Replace if Necessary

Vane ClosedSwitch Vanes Open

Run Oil Pump AndCheck Vane Operation

Flush Needle Valve if NecessaryDisassemble IGV

Assembly and Check

Compressor Time Bad Contacts on RelayDelay (TDR) Bad Relay

Check ContinuityCheck Coil

Replace if Necessary

Replace if Necessary

Oil PumpTime Delay

(OTD)

instantaneous Contacts

OpenBad Coil

Check Continuity& Resistance

Replace or Repair

CompressorInterlocks

Chilled Water Pump Off

Condenser Pump OffCheck Starter CoilCheck OverloadsCheck Fuses

Repair

OrReplace

Guardistor

Circuit Guardistor Circuit Open

Check CapacitorCheck ContinuityOne Direction Only

200-900 Ohms

Replace

Check Internal Connections

Cycling

Thermostat

(CT)

Open ContactsSet To High

Discharged Element

Check ContinuityObserve SettingAdj. From High to LowIf Still Open

Replace

AdjustReplace

Starter

OverloadTripped

Current Limiter Module

Current Transformer

Grounded or ShortedMotor

See Electronic Control Check

Page 7Check Output

Voltage at 100%

Capacity ShouldBe 4.5 5.5 Volts

Megger Windings

Repair or Replace

Repair or Replace

Repair ConnectionsOr Replace Stator

-Continued Next Page

16

TROUBLE DIAGNOSIS CHART - (continued)

COMPRESSORS CYCLES OFF

POSSIBLE CAUSE POSSIBLE REASON VERIFICATION REMEDY

Cycling

Thermostat

Low Load

Low Water Flow

Set Higher Than

Control Module

Thermostat

Check Load

Check Pump Strainer

Observe Setting

Correct

Clean

Reset

Refrigerant Shortage Of

Temperature Refrigerant

Check Charge Check- Repair

Leaks Add Gas

High Head

Pressure

Non Condensables

High Condensing Temp.

Low Water Flow

Dirty Condenser Tubes

Little Temperature

Rise on Condenser

Water Flow

Check Tower Fan Operation

Check Strainer

Little Or No Temp Rise On

Water

Purge Non Cond.

Repair

Clean Strainer

Clean Tubes

High Discharge Low LoadVanes Closed

Load Compressor Check

Check Vane Operation

Correct

Repair

HighOil

Temperature

Oil Cooler Solenoid

Not Openrng

Hand Valve OffStrainer Plugged

Low Flow

Check Coil

Check Connection:.

Check Valve

Remove Et InspectCheck For Proper Flow

Replace if Necessary

Tighten Or Repair

Open

CleanAdjust

RUNS NOTCOOLING

POSSIBLE CAUSE POSSIBLE REASON VERIFICATION REMEDY

Low Oil Pressure

Plugged Needle ValveElectronic

Motor Control

Solenoids ClosedSA & SBElectronic TemperatureControlSolenoid Control

Circuit Off-___

CheckOpen Wide

Check SettingRefer To Electronic

Check Chart

Check Coils

Check ConnectionSee Electronic Check Chart

Check Starter

Interlock Connect ions_-___ -____

Flush Et Adjust

Reset

Replace If Neccessary

Clean ContactsOr Repair Wires

I.G.V. Closed

17

WESTINGHOUSE CENTRIFUGAL OPERATORS LOG

The weekly maintenance of a log is highly recommended by Westinghouse Corporation for the following reasons.

1.. It provides an itemized checklist of critical system components.

2. It provides a systematic record that wiil allow you to identify trends that may be leading to future componentfailure.

3. This log and the following information is sufficient for factory computer analysis of your chiller’s performance.

(a)Capacity control current settinq-%

(b)Water temperature set point _

(c)Temperature setting of cycling thermostat ~

Definitions of column headings:

Condenser and chiller water pressure drops: from inlet and outlet gauges in psi or differential pressure gauge ininches of mercury or feet of water. (1 psi = .4911 in. - Hg. = 2.307 ft H,O = .3416 kg/CM* = 6.9 Kilopascal

Compressor Amps: The greatest amperage of the three lines should be recorded.

Suction Superheat = Suction Line Temperature - Measured Liquid Line Temperature

Condenser Subcooling = Saturated Condenser Refrigerant Temperature Measured Liquid Line Temperature

NOTE: Liquid line temperature should be measured on line between condenser and service valve

Oil temperature leaving cooler: This temperature should be measured mid-way between cooler and oil filter housing. During normal running it

should be maintained between 80” and 1 lOoF.

Job number is the Westinghouse shop order number found on the main nameplate. PE/PF/PH, etc., followed by 4 digits. This number is

important anytime you need to contact the factory.

Full Load Design Conditions are listed on the Westinghouse shop order. If these have not been supplied by the contractor or engineer, they are

available from Westinghouse CIACD, P.O. Box 2510, Staunton, Virginia 24401, U S.A.

‘FAHRENHEIT = OF = ‘C x 915 + 32

’ CELSIUS = OC = loF -3215/g

Extra copies of the Operators Log Sheet may be obtained by ordering from the factory. Log sheets will be supplied in tablet formdesignated by part number Cl-344.

18