Carrier GR-45 Operation And Service

Contents

Carrier GR-45 Operation And Service Manual pdf 36 page image

T-2954-3DS1 61023457891. Filter-Drier InletService Valve2. ThermostaticExpansion Valve3. Manifold GaugeSet4. Thermistor VacuumGauge5. Vacuum Pump6. Refrigerant Cylinder7. Reclaimer8. Filter-Drier9. Liquid SolenoidValve10. Filter-Drier OutletService ValveFigure 4-4. Low Side Pump Down Connectionsi. Re--connect suction pressure transducer and removelow pressure switch jumper. If required, clear anyalarms that have been generated during this proce-dure.j. Open service valves and check refrigerant level. Re-fer to paragraph 4.8.1.4.5.2 Refrigerant Removal From An InoperativeCompressor.To remove the refrigerant from a compressor that is notoperational, do the following:a. Attach a manifold gauge set as shown in Figure 4-5and isolate the compressor by frontseating the suctionand discharge valves.b. Recover refrigerant with a refrigerant reclaimer. If thedischarge service valve port is not accessible, it willbe necessary to recover refrigerant through the suc-tion service valve port only.c. Service or replace components as required and leakcheck the compressor.d. Using refrigerant hoses designed for vacuum service,connect a vacuum pump to center connection of man-ifold gauge set. Evacuate system to 500 microns.Close off pump valve, isolate vacuum gauge and stoppump. Wait 5 minutes to verify that vacuum holds.e. Once vacuum is maintained, recharge low side to 20to 30 psig (1.36 to 2.04 bar) by admitting vapor fromthe refrigerant cylinder. Disconnect manifold gaugeset and backseat compressor service valves.f. Check refrigerant level. Refer to paragraph 4.8.1. Itmay be necessary to clear any alarms that have beengenerated.DS71234561. Discharge ServiceValve and Port2. Suction ServiceValve and Port3. Manifold GaugeSet4. Vacuum Pump5. Reclaimer6. Refrigerant Cylinder7. Thermistor VacuumGaugeFigure 4-5. Compressor Service Connections4.5.3 Pump Down An Operable Compressor ForRepairTo service an operable compressor, pump the refrigerantinto the condenser coil and receiver as follows:a. Install manifold gauge set. Refer to Figure 4-5.b. Frontseat the compressor suction service valve byturning clockwise.c. Place a jumper on the low pressure switch. Start theunit and run in cooling until 10 ”/hg (25.4 cm/hg) ofvacuum is reached. Shut the system down.d. Frontseat the compressor discharge service valve andwait 5 minutes to verify vacuum is maintained. If thepressure rises above vacuum, open the compressordischarge service valve and repeat steps c and d until avacuum is maintained.e. Service or replace components as required and leakcheck the compressor.f. Using refrigerant hoses designed for vacuum service,connect a vacuum pump to center connection of man-ifold gauge set. Evacuate system to 500 microns.Close off pump valve, isolate vacuum gauge and stoppump. Wait 5 minutes to verify that vacuum holds.g. Once vacuum is maintained, re--connect low pressureswitch, disconnect manifold gauge set and open com-pressor service valves.h. Check refrigerant level. Refer to paragraph 4.8.1. Itmay be necessary to clear any alarms that have beengenerated.