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Page 1: Single/Dual Compressor Centrifugal Chillers · step start functions of its host centrifugal compressor unit, monitor and regulate the compressors capacity, protect it, and sequence

Supersedes: new

Single/Dual Compressor Centrifugal ChillersPEH/PHH 050,063,079,087, 100, 126PFH/PJH 050,063,079,087, 126

0 1996 McQuay International

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Page 3: Single/Dual Compressor Centrifugal Chillers · step start functions of its host centrifugal compressor unit, monitor and regulate the compressors capacity, protect it, and sequence

Introduction

General DescriptionThe McQuay Model PE Centrifugal Water Chillers are complete, self-contained, automatically controlledwater chilling units. Each unit is completely assembled and factory tested before shipment.

In the PEH series, each unit contains one compressor connected to a condenser and evaporator. Asister model, the PHH Heat Recovery Chiller is similar to the PEH models except for the substitution of asplit condenser (two water circuits) for heat recovery applications. The PHH models are equipped witha hot-gas bypass system for operation at light cooling loads. This hot gas system is standard on PHHunits and optional for PEH models.

The PFH series are equipped with two compressors operating in parallel on a single evaporator andcondenser. Model PJH series are the equivalent double bundle heat recovery units.

The standard chillers use refrigerant R- l34a, to reduce the size and weight of the package comparedto negative pressure refrigerants and since R-134a operates at a positive pressure over the entireoperation range, no purge system is required.

The controls are pre-wired. adjusted and tested. Only normal field connections such as piping,electrical and pump interlocks, etc. are required thereby simplifying installation and increasing reliability.All necessary safety and operating controls are factory installed in the control panel.

The basic sizes of units are the PEH/PHH/PFH/PJH 048,050,063,076,079,087 , 100 and 126. Theyprovide a capacity range from 80 tons to 2500 tons. In this manual all references to the PEH models willequally apply to other models unless specifically referenced otherwise.

ApplicationThe operation and maintenance procedures presented in this manual apply to the standard PEH familyof chillers. Reference to the Installation Manual, IM 306 for these units should be made for detailspertaining to receiving and handling, installation. piping and wiring, and preparation for initial startup.

All McQuay centrifugal chillers are factory tested prior to shipment and must be initially started atthe job site by a factory trained McQuayService technician. Failure to follow this startup proceduremay affect the equipment warranty.

The standard warranty on this equipment covers parts which prove defective in material orworkmanship. Specific details of this warranty can be found in the warranty statement furnished withthe equipment and also found at the end of this manual.

Cooling towers used with McQuay model PE centrifugal chillers are normally selected for maximumcondenser inlet water temperatures between 75°F and 90°F (24°C and 32°C). Lower entering watertemperatures are desirable from the standpoint of energy reduction but a minimum does exist. Forrecommendations for optimum entering water temperature and cooling tower fan control, consultMcQuay Catalog 955. Applications Section.

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Operation

Operator ResponsibilitiesIt is important that the operator become familiar with the equipment and the system before attempting tooperate the chiller. In addition to reading this manual the operator should study installation andoperation bulletin IM6 16 and the control diagram furnished with the unit so that he understands thestarting, operating and shutdown sequences as well as the safety shutdown modes.

During the initial startup of the chiller the McQuay technician will be available to answer anyquestions and instruct in the proper operating procedures.

It is recommended that the operator maintain an operating log for each individual chiller unit. Asuggested log sheet is shown on page 19 of this manual.

In addition, a separate maintenance log should be kept of the periodic maintenance and servicingactivities.

This McQuay centrifugal chiller represents a substantial investment and deserves the attentionand care normally given to keep this equipment in good working order. If the operator should encoun-ter abnormal or unusual operating conditions, it is recommended that a McQuayService technician beconsulted.

McQuay International conducts training for McQuay centrifugal operators at its factory TrainingCenter several times a year. These sessions are structured to provide basic classroom instruction andinclude hands-on operating and troubleshooting exercises. For further information, contact yourMcQuay representative.

NomenclatureEach centrifugal chiller is assigned a set of identifying numbers which are used to describe the unitfeatures and to identify each individual unit. These number groups are stamped on each unit name-plate.

All inquiries pertaining to operating and servicing of this unit should include all identificationnumbers.

Each of the major individual components also have nameplates to provide certain necessaryinformation to the installer and the operator.

Compressors are designated as model CE. For example a model CEO50 compressor is used on amodel PEHO5O chiller unit. The compressor nameplate identifies the compressor model, style and serialnumber and includes the electrical characteristics of the compressor motor. The CEO50 compressornameplate also shows the oil pump electrical characteristics.

The condenser and evaporator vessels have nameplates stamped with the maximum workingpressure of the vessel, the National Board Number, and the vessel style number. It should be notedthat the vessel relief valve maximum settings coincides with the maximum refrigerant side vesselworking pressure.

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MicroTech Control PanelThe MicroTech unit controller is a microprocessor based control panel designed to initiate the step-by-step start functions of its host centrifugal compressor unit, monitor and regulate the compressorscapacity, protect it, and sequence the compressor shutdown on lack of load or in response to a presettime. On dual compressor units, each compressor has its own controller. They are interconnected toprovide lead-lag and load-balance functions.

The full information on the features, installation, operation and problem analysis of the McQuaymicroprocessor control for Centrifugal chillers, see Installation and Operation Manual IM 616 andOperators Manual OM125. The MicroTech panel provides a wide range of control options and datareporting and recording capability. Familiarity with the control system is important for optimum unitoperation.

Figure 1. MicroTech Control Panel

Capacity Control SystemThe compressor capacity is controlled by the movement of the inlet vanes, opening or closing to permitthe correct quantity of refrigerant to enter the impeller, The vane movement occurs in response to oilflow frotn the SA or SB solenoid valves which, in turn. respond to a control module signal. This oil flowactivates a piston to rotate the vanes.

Vane Operation

The hydraulic system for the inlet guide vane capacity control operation consists of a 4-way normallyopen solenoid valve located in the oil management control panel. Oil under pressure from the oil filter isdirected by the 4-way valve to either or both sides of the piston depending on whether the controlsignal is to load, unload, or hold.

To open the vanes (or load the compressor) solenoid SA is de-energized and solenoid SB isenergized, allowing oil flow from port SA to one side of the piston then drain through port SB.

To close the vanes (unload compressor) valve SB is de-energized and valve SA is energized tomove the piston and vanes toward the unload position.

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When both solenoid valves SA and SB are de-energized, full oil pressure is directed to both sidesof the piston through ports SA and SB, thus the vanes are held in that position. Refer to figures 3 and 4for solenoid action. Note that both solenoids cannot be energized simultaneously.

Metering Values

The speed at which the capacity control vanes are opened or closed can be adjusted to suit systemoperating requirements. Adjustable needle valves in the oil drain lines are used to control the rate ofbleed-off and consequently the “vane speed”. These needle valves are part of the 4-way solenoid valveassembly located in the compressor lube box (Figure 2).

The valves are normally factory set so the vanes will move from fully closed to fully opened inapproximately 3 minutes and from fully open to fully closed in 1 minute (except CEI 26). The speedshould be slow enough to prevent over-controlling and hunting.

Vane Speed Adjustment

The vane speed at which the capacity control vanes open or close is controlled by the rate of oil bleed-off from the vane actuating position. This bleed-off rate is adjustable by positioning the needle valveson SA and SB solenoid valves located in the lube box.

Screwdriver openings in the left side of the lube box permit access. The upper opening accessesthe SB needle valve for adjusting the vane OPENING speed for loading the compressor (refer to Figure2). Turn this screw clockwise to decrease the vane opening and counterclockwise to increase theopening speed.

The lower opening accesses the SA needle valve for adjusting the CLOSING speed for unloadingthe compressor. The same adjustment applies clockwise to decrease closing. counterclockwise toincrease vane closing.

The vane speed is factory set and varies by compressor size:

Compressor Model Opening Time

CEO48 - CEO50 2 - 2 1/2 min.

CEO63 - CE1 00 3 - 5 min.

CE126 5 - 8 min.

Closing Time

3/4 - 1 min.

1 - 2 min

1 - 2 min.

FiguIre 2. Lube Box

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Oil SystemThe oil system for the PEH family of units provides lubrication and heat removal for compressorbearings and internal parts. In addition, the system provides oil under pressure to hydraulically operatethe unloading piston for positioning the inlet guide vanes for capacity control. PFH dual compressorchillers have completely independent lubrication systems for each compressor.

Proper operation of the hydraulic system and bearing lubrication system can be assured only ifrecommended oil is used, recommended oils are shown in Table 1. Each unit is factory charged with thecorrect amount of the recommended oil. Under normal operation, no additional should be needed. Oilshould be visible in the oil sump sight glass at all times.

The oil pump for the CE038/050 compressor is completely self-contained within the compressorhousing. The assembly includes the pump, pump motor, oil heater and oil separator. The oil is pumpedthrough the oil discharge line to the oil filter in the compressor casting and then to the internal refriger-ant-cooled oil cooler.

The other compressor sizes-CE063. through CE1 26-utilize a separate oil pump contained in the oilreservoir. This assembly includes pump, motor, heater and oil separator system. Oil is pumped throughthe external oil cooler and then to the oil filter located inside the compressor housing. Standard PEH/PHH 063- I26 units utilize a water-cooled oil cooler although an optional refrigerant-cooled oil cooler isavailable. All dual compressor PFH/PJH chillers are equipped with refrigerant-cooled oil coolers asstandard.

The oil coolers maintain the proper oil temperature under normal operating conditions. The coolantflow control valve should maintain 9O”F- 100°F (32”C-38°C). Lubrication protection for coast down inthe event of a power failure is accomplished by a spring loaded piston in models CEO50 through 100.When the oil pump is started, the piston is forced back by the oil pressure, compressing the spring andfilling the piston cavity with oil. When the pump stops. the spring pressure on the piston forces the oilout to the bearings.

In model CEI 26 the compressor coast down lubrication is supplied from a gravity feed oil reservoir.

A typical flow diagram is shown in figure 5.

Table I Approved Polyolester Oils For R-134a Units

Compressor Models CE048/050, 063, 0761079, 087 CE100, 126

Lubricant Designation Mobil Artic EAL 22: Mobil Artic EAL 46;ICI Emkarate RL22N (1) ICI Emkarate RL32H@

McQuay Part Number

55 Gal. Drum 735030430, Rev 47 735030432, Rev 47

5 Gal. Drum 735030431, Rev 47 735030433, Rev 47

1 Gal. Can 735030434. Rev 47 735030435, Rev 47

Compressor Oil Label 070200105, Rev OB 070200106, Rev OB

1. ICI RL22S and 22H are not approved, only RL22N is acceptable2. ICI RL32S Ester lubricant is not approved, only RL32H is acceptable

3. Approved Oil from two suppliers can be mixed.

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Figure 5. Typical Oil Flow Diagram

COMPRESSOR7

PISTONDRAIN C

HEATER

UNLOADERPISTON

I 1

THRUSTPUMP

BYPASS RELIEFi , V A L V E

_ PUMP ’ OIL SUMP

. FILTER

OILCOOLEf

I

OUTCOOLIN

.ING WATER

I. Does not apply to CE 04X.050 compressors2. Refrigerant cooled oil coolers use high pressure refrigerant

expanded t h r u a temperature control valve.3. Connections not necessarily in correct relative location

Hot Gas BypassThe PHH and PJH heat recovery chillers are equipped as standard with a hot gas bypass system usedto feed discharge gas directly into the evaporator when the system load falls below a predeterminedminimum compressor capacity. PEH and PFH units can be so equipped as an option when operationbelow the minimum 10 % compressor capacity is desired.

Light load conditions are signaled by measurement of a set percentage of RLA amps by theMicroTech control panel. When the RLA drops to the setpoint the hot gas bypass solenoid is ener-gized making hot gas bypass available for use. This introduction of hot gas provides a stable refriger-ant flow and keeps the chiller from short cycling under light load conditions. It also prevents surgeduring heat recovery operation.

The factory setpoint for bringing on hot gas bypass is 40% of RLA. See IM 6 16.

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Maintenance

Routine Maintenance

Lubrication (See Caution)

After the system is once placed into operation, no other additional oil is required except in the eventthat repair work becomes necessary to the oil pump or unless a large amount of oil is lost from thesystem due to a leak.

If oil must be added with the system under pressure, use a hand pump with its discharge lineconnected to the service valve at the bottom of the oil pump. (The CEO50 compressor with its internaloil pump is equipped with an oil service valve on the compressor. The synthetic oils used with R-l 34aare hydrophilic and care should be exercised to avoid exposure to moisture.

Changing Oil Filters (See Caution)

McQuay chillers are at positive pressure at all times and do not leak contaminated moist air into therefrigerant circuit eliminating the need for annual oil changes.

CEO50 Compressors-If the unit is equipped with a suction line service valve (dual compressorunits are so equipped as standard), close this valve and close the valve on the motor cooling liquid lineto isolate the compressor. Remove the refrigerant from the compressor using approved procedures.Remove the filter cover and the old filter and install the new filter, open end first. Replace the coverusing a new gasket. Reopen the suction and liquid line valves.

If the unit is not equipped with a suction line service valve, the unit will have to be pumped downin order to remove the pressure in the compressor before removing the cover and changing the filter.Refer to later section for pumpdown procedure.

CEO63 and Larger Compressors-The oil filter in each of these machines can be changed by simplyisolating the filter cavities. Close the oil discharge line service valve at the oil pump (at the filter onCE 126). Remove the filter cover: some foaming may occur but the check valve should limit leakage fromother compressor cavities. Remove the filter, replace with new element and replace filter cover usingnew gasket. Reopen valve in pump discharge line.

When machine is operated again, the oil level should be checked to determine if oil needs to beadded to maintain the proper operating level.

Caution

Improper servicing of the lubrication system, including the addition of excessive or incorrect oil,substitute quality oil filter, or mishandling of the equipment under pressure is hazardous. Only autho-rized and trained service personnel should attempt this service. For qualified assistance, contact yourlocal McQuay Service technician.

Refrigerant Cycle

Maintenance of the refrigerant cycle consists of maintaining a log of the operating conditions, andassuring the unit has the proper oil and refrigerant charge. (See the maintenance schedule and theappropriate operating log at the end of this bulletin)

At every inspection, the oil, suction and discharge pressures should be noted and recorded, aswell as condenser and chiller water temperatures.

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The suction line temperature at the compressor should be taken at least once a month. Subtractingfrom this, the saturated temperature equivalent of the suction pressure will give the superheat. Extremechanges in superheat over a period of time will indicate losses of refrigerant or possible deterioration ofthe expansion valves. Proper superheat setting is 1 l/2 to 2 degrees Fahrenheit (1 degree Celsius) at fullload. Such a small temperature difference can be hard to measure accurately. Another method is tomeasure the compressor discharge superheat, the difference between the actual discharge temperatureand the saturated discharge temperature. The superheat should be between 14 and 16 degrees Fahren-heit (8 to 9 degrees Celsius) at full load. The liquid injection should be deactivated (remove relay #10)when taking the discharge temperature. The superheat will increase linearly to 55 degrees Fahrenheit(30 degrees Celsius) at 10% load. The Series 200 MicroTech Control can display all superheat andsubcooling temperatures.

Figure 8. Typical Refrigerant Flow Diagram

CHII-LED

LIQUID

T

p/OUT

CONDENSED WATER

IIN

w

&TCONDENSER

NOTE 2rTEXPANSION‘?4LVE

FILTERDRIER

Electrical System

Maintenance of the electrical system involves the general requirement of keeping contacts clean andconnections tight and checking on specific items as follows:

1. The compressor current draw should be checked and compared to nameplate RLA value. Normallythe actual current will be lower since the nameplate rating represents full load operation. Also checkall pump and fan motor amperages and compare with nameplate ratings.

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2.

3.

4.

5.

6.

Inspection should verify that the oil heaters are operative. The heaters are insert cartridge type andcan be checked by ammeter reading. They should be energized whenever power is available to thecontrol circuit and when the compressor is inoperative). When the compressor starts the heatersare de-energized.

At least once a quarter, all safety controls except compressor overloads should be made to operateand their operating points checked. Any control may shift its operating point as it ages, and thismust be detected so the controls can be adjusted or replaced. Pump interlocks and flow switchesshould be checked to be sure they interrupt the control circuit when tripped.

The contactors in the motor starter should be inspected and cleaned quarterly. Tighten all terminalconnections.

The compressor motor resistance to ground should be checked and logged semi-annually. This logwill track insulation deterioration. A reading of 5 megohms or less indicates possible insulationfailure and should be further checked.

The centrifugal compressor must rotate in the direction indicated by the arrow on the casting nearthe rotation sightglass. If the operator has any reason to suspect that the power system connec-tions may have been altered, (phases reversed) the compressor should be jogged to check rotation.For assistance. call McQuayService.

Cleaning and Preserving

A common cause of service calls and equipment malfunction is dirt. This can be prevented with normalmaintenance. The system components most subject to dirt are:

1. Permanent or cleanable filters in the air handling equipment must be washed in accordance with themanufacturer’s instructions; throwaway filters should be replaced. The frequency of this servicewill vary with each installation.

2. Remove and clean strainers in chilled water system, oil cooler line and condenser water system atevery inspection.

Seasonal ServicingPrior to shutdown periods and before starting up again, the following service procedures should becompleted.

Annual Shutdown

1. Where the chiller may be subject to freezing temperatures, the condenser and chiller water pipingshould be disconnected and drained of all water. Dry air blown through the condenser will aid inforcing all water out. Removal of condenser heads is also recommended. The condenser andevaporator are not self-draining. Water permitted to remain in the piping and vessels will rupturethese parts if subjected to freezing temperature.

Forced circulation of antifreeze through the water circuits is the only sure method of avoidingtrouble.

2. Take measures to prevent the shutoff valve in the water supply line from being accidentally turnedon.

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

4. Open the compressor disconnect switch, and remove the Fusetrons. If the transformer is used forcontrol voltage, the disconnect must remain on to provide power to the oil heater. Set the manualstop/auto switch (SWI) to the stop position. To insure against the possibility of an accidental start,remove the fault relay from the left side of the MicroTech panel (see IM 616).

5. Check for corrosion and clean and paint rusted surfaces.

6. Clean and flush water tower for all units operating on a water tower. Make sure tower “blowdown”or bleed-off is operating. Set up and use a good maintenance program to prevent “liming up” ofboth tower and condenser. It should be recognized that atmospheric air contains many contami-nants which increase the need for proper water treatment. The use of untreated water may result incorrosion, erosion, sliming, scaling or algae formation. It is recommended that the service of areliable water treatment company be used. McQuay International assumes no responsibility for theresults of untreated or improperly treated water.

7. Remove condenser heads at least once a year to inspect the condenser tubes and clean if required.

Annual Startup

A dangerous condition can exist if power is applied to a faulty compressor motor starter which has beenburned out. This condition can exist without the knowledge of the person starting the equipment.

This is a good time to check all the motor winding resistance to ground. Semi-annual checking andrecording of this resistance will provide a record of any deterioration of the winding insulation. All newunits have well over 100 megohms resistance between any motor terminal and ground.

Whenever great discrepancies in readings occur or uniform readings of less than 5 megohms areobtained, the motor cover should be removed for inspection of the winding prior to starting the unit.Uniform readings of less than 5 megohms indicate motor failure is imminent and motor should bereplaced or repaired. Repair before failure occurs can save a great deal of time and labor expended inthe cleanup of a system after motor burnout.

1.

2.

3.

The control circuit should be energized at all times. If the control circuit has been off and oil is cool,energize oil heaters and allow 24 hours for heater to remove refrigerant from the oil before starting.

Check and tighten all electrical connections.

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

4. Install Fusetrons in main disconnect switch (if removed).

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

6. Refer to Manual IM 6 16 before energizing the compressor circuit.

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Repair of System

Pumping Down

If it becomes necessary to pump the system down. extreme care should be used to avoid damage to theevaporator from freezing. Always make sure that full water flow is maintained through the chiller andcondenser while pumping down. To pump the system down, close all liquid line valves. With all liquidline valves closed and water flowing, start the compressor. Set the MicroTech panel to the manual load(see IM 6 16). The vanes must be open while pumping down to avoid a surge or other damagingcondition. Pump the unit down until the MicroTech cuts out at approximately 20 psig. It is possiblethat the unit might experience a mild surge condition prior to cutout. If this should occur, immediatelyshut off the compressor. Use a portable condensing unit to complete the pump down, condense therefrigerant, and pump it into the condenser or pumpout vessel.

Pressure Testing

No pressure testing is necessary unless some damage was incurred. After repairs are made, pressuretest the system at a pressure that does not exceed the standby pressure in the condenser. (A testpressure higher than condenser pressure would open the discharge check valve and allow flow of testpressure into condenser). In cases where the entire refrigerant charge is lost. refer to the followingparagraphs. The evacuation procedure can be followed in both cases.

Leak Testing

In case of the loss of the entire refrigerant charge. the unit should be checked for leaks prior to chargingthe complete system. This can be done by charging only enough refrigerant into the system to buildthe pressure up to approximately 10 psig and adding sufficient dry nitrogen to bring the pressure up toa maximum of 125 psig and then leak test with halide or electronic leak detector. Caution: Do not useoxygen to build up pressure, as a serious explosion can result. A pressure regulating valve shouldalways be used on the drum being used to build the system pressure. Also, do not exceed the testpressure given above. When the test pressure is reached disconnect the gas cylinder.

If any leaks are found in welded or silver soldered joints or if it necessary to replace a gasket.relieve the test pressure in the system before proceeding. For copper joints, silver solder is recom-mended.

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

Evacuation

After it has been determined that there are no refrigerant leaks, the system should be evacuated using avacuum pump with a capacity of approximately 3 cu.ft./min. and that will reduce the vacuum to at least 1millimeter( 1000 microns).

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

The triple evacuation method is recommended and is particularly helpful if the vacuum pump isunable to obtain the desired I millimeter of vacuum. The system is first evacuated to approximately 29inches of mercury. Enough refrigerant vapor is then added to the system to bring the pressure up tozero gauge pressure. Then the system is once again evacuated to approximately 29 inches of mercury.This is repeated 3 times. The second pull down will remove about 90% of that remaining from the firstpull down and after the third, only 1/10 of 1 c% non-condensibles will remain.

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Refrigerant Charging

Since January 1993, all McQuay centrifugal chillers use R- 134a. R- 12, or R-500 refrigerants may havebeen used prior to December 1992. Therefore it is recommended that the operator check the unitnameplate to assure the correct refrigerant selection prior to charging or adding refrigerant.

An initial operating charge of R- 134a is made at the factory prior to shipment. In the event theoperator needs to add refrigerant after the unit is installed, certain precautions should be taken toprotect equipment components. Refrigerant charging lines must be kept dry, clean and free of non-condensable gasses. Care should be taken on selecting the best charging point in the unit so as toprotect the unit from damage.

If the entire charge is lost or removed from the unit, recharging can be accomplished quickly andsafely by introducing the liquid refrigerant directly into the bottom of the evaporator with the expansionvalve manually opened. Both condenser water and chilled water must be flowing through the respec-tive vessels to prevent localized freezing. Consult the chiller nameplate for the proper refrigerantcharge.

With a near-normal charge in the system, final charging can best be accomplished with the unitrunning at full load. In this operating mode the unit should be charged until suction superheat isbetween 1 l/2 to 2 degrees Fahrenheit (1 degree Celsius). or by the discharge superheat as explainedearlier. Adjusting the thermal expansion valve as necessary. Continue charging until 8 to 10 degreesFahrenheit (4.5 to 5.5 degrees Celsius) liquid subcooling is obtained leaving the condenser if the unit isoperating at full load. At less than full load, liquid subcooling will be proportionally less.

Pressure Relief Valve Replacement

Current condenser designs use two relief valves ( 1 set) separated by a three way shutoff valve. Thisvalve allows either relief valve to be shut off, but at no time can both be shut off. In the event one ofthe relief valves is leaking in the two valve set, the following procedures should be followed:

If the valve closest to the valve stem is leaking, back seat the three-way valve all the way, closingthe port to the leaking pressure relief valve. Remove and replace the faulty relief valve. The three-wayshutoff valve should remain either fully back seated or fully forward to normal operation. If the reliefvalve farthest from the valve stem is leaking, front seat the three-way valve and replace the relief valveas stated above.

The refrigerant in the evaporator must be pumped down to the condenser to replace its relief valve.

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Service Programs

It is important that an air conditioning system receive adequate maintenance if the full equipment lifeand full system benefits are to be realized.

Maintenance should be an ongoing program from the time the system is initially started. A fullinspection should be made after 3 to 4 weeks of normal operation on a new installation and on a regularbasis thereafter.

McQuay offers a variety of maintenance services through McQuayService, its nationwide serviceorganization, and can tailor these services to suit the needs of the building owner. Most popular amongthese services is the McQuayService Comprehensive Maintenance Contract.

For further information concerning the many services available, contact your local McQuayServicerepresentative.

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