ICE MACHINES Q-Model Service Manual

Section 7Refrigeration SystemREMOTE MODELSEVAPORATORHEATEXCHANGEREXPANSION VALVECOMPRESSORSTRAINERXHARVEST SOLENOID VALVECHECK VALVEREMOTECONDENSERLIQUIDLINESOLENOIDVALVEDRIERHARVEST PRESSUREREGULATING VALVEXH.P.R. SOLENOIDVALVEHEADPRESSURECONTROLVALVERBCHECK VALVECRECEIVERSERVICEVALVERECEIVERHIGH PRESSURE VAPOR HIGH PRESSURE LIQUID LOW PRESSURE LIQUID LOW PRESSURE VAPORFigure 7-3. Remote Pre-Chill and Freeze Cycle (Models 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 evaporators. The suctionpressure decreases during the prechill.SV1566The refrigerant absorbs heat from the water running overthe evaporator surface. The suction pressure graduallydrops as ice forms.The headmaster control valve maintains dischargepressure in ambient temperatures below 70°F (21.1°C).(See “Headmaster Control Valve” on Page 7-30.)Part No. 80-1100-3 7-3