ICE MACHINES Q-Model Service Manual

Section 7Refrigeration SystemSequence of OperationSELF-CONTAINED AIR OR WATER -COOLED MODELSEVAPORATORHEATEXCHANGEREXPANSION VALVEHARVEST SOLENOID VALVECOMPRESSORSTRAINERXAIR OR WATERCONDENSERDRIERRECEIVER(WATER COOLED ONLY)HIGH PRESSURE VAPORHIGH PRESSURE LIQUIDLOW PRESSURE LIQUIDLOW PRESSURE VAPORSV1569Figure 7-1. Self-Contained Prechill and Freeze Cycle(Models Q200/Q280/Q320/Q370/Q420/Q450/Q600/Q800/Q1000)Prechill Refrigeration SequenceFreeze Cycle Refrigeration SequenceNo water flows over the evaporator during the prechill.The refrigerant absorbs heat (picked up during theharvest cycle) from the evaporator. The suction pressuredecreases during the prechill.The refrigerant absorbs heat from water running over theevaporator surface. The suction pressure graduallydrops as ice forms.Part No. 80-1100-3 7-1