Carrier AQUAFORCE 30XW150-400 Operation & Service Manual

Contents

63Compressor Assembly — The 30XW units utilizescrew compressors with a modulating slide valve which variescapacity from 15% to 100% of compressor capacity for eachcircuit. See Fig. 45 for a view of a typical 06T compressor.The slide valve position is varied by opening and closing the2 solenoid valves located on the compressor. To unload thecompressor, both solenoids are deenergized. To increase incapacity both solenoid valves are energized together whichwill cause the slide valve to slide towards the fully loaded posi-tion. To stop the loading process solenoid 2 is energized andsolenoid 1 is deenergized. This will cause the slide valve tomaintain its current position. There is no feedback for the posi-tion of the slide valve. The control utilizes compressor currentas an indicator of the slide valve position. Once the calculatedposition of the slide valve reaches 100% circuit capacity, thecontrol will try to increase capacity again if the compressorcurrent continues to increase. The control will continue to loadthe compressor until the compressor current no longerincreases. At that time the control will energize both solenoidsand the circuit will be considered fully loaded.COMPRESSOR OIL SYSTEM — Each compressor/circuithas its own oil system which includes an oil filter, oil solenoid,check valve, oil level switch, oil pressure transducer, and an oilshut-off valve. A typical oil system is shown in Fig. 46. SeeTable 42.Table 42 — Unit Oil Quantities30XW UNIT SIZE OIL CHANGE (gal, [liters])Circuit A Circuit B150-200 6.0 [22.7] —325-400 5.0 [18.9] 5.0 [18.9]Fig. 45 — Typical 06T CompressorSOLENOID 1SOLENOID 2HIGH PRESSURESWITCHMOTOR TEMPERATURESENSOR 2COMMONMOTOR TEMPERATURESENSOR 1t ex tCompressionProcessHigh Pressure OilDe- energizedFLOWValve #2 ( NO)De-energizedNO FLOWValve #1 ( NC)B leed Line to Low Pressure SuctionlD isch arg eP ortUnloader PistonChamberte xtCompressionP rocessLoaded Posi tionHigh Pressure OilEnergizedNO FLOWValve #2 ( NO)EnergizedFLOWVal ve #1 (NC)Bleed Line to Low Pressure S uctionSlide ValveDisc hargePortUnloader PistonChamberLoaded PositionHigh withHighPressureOilDrain toLow PressureUnloaded PositionSlide Valvet extHigh Pressure OilTrappedOil atHighPressureCompressionProcessPart Load PositionEnergizedNO FLOWValve #2 (NO)De-energiz edNO FLOWValv e #1 (NC)Bleed Line to Low Pressure SuctionSlide ValveD is ch ar g ePo r tUnloader Pist onChamberSlide ValveFULLY LOADED OPERATION FULLY UNLOADED OPERATION MAINTAIN POSITIONDISCHARGEGAS THERMISTORACCESSFITTINGSUCTIONTEMPERATUREA30-484112345678Fig. 46 — Typical Oil SystemA30-4842LEGEND1 — Oil Pressure Transducer2 — Oil Solenoid3 — Oil Filter4 — 1/ 4 in. FL (Female) Access Fitting5 — Shut-Off Valve6 — Oil Level Sight Glass7 — Oil Level Switch8 — 1/ 4 in. FL (Female) Access Fitting