Manitowoc QF0400 Service Manual

Also see for QC0700: Installation, use & care manual Service manual Building instructions Technician's handbook

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Manitowoc QF0400 Service Manual Manual pdf 117 page image

Section 6 Electrical SystemPart No. 80-1214-3 6-55HIGH PRESSURE CONTROL (HPCO)FunctionThe high pressure control stops the ice machine ifsubjected to excessive high-side pressure.The HPCO control is normally closed, and opens on arise in discharge pressure.SpecificationsCut-out:450 psig ±10Cut-in:Automatic reset(must be below 300 psig to reset).Check Procedure1. Set ICE/OFF/CLEAN switch to OFF.2. Disconnect main power supply to the ice machine.3. Connect manifold gauges to access valves.4. Hook voltmeter in parallel across the HPCO, leavingwires attached.5. Reconnect main power supply to the ice machine.6. Set ICE/OFF/CLEAN switch to ICE and blockcondenser with cardboard or similar material.7. No air flowing through the condenser will cause theHPCO control to open because of excessivepressure. Watch the pressure gauge and record thecut-out pressure.Replace the HPCO control if it:• Will not reset (below 300 psig).• Does not open at the specified cut-out point.LOW PRESSURE CUT-OUT CONTROL (LPCO)RFC2085/RFC2385 (QF2200/QF2300) ONLYFunctionEnergizes and de-energizes the contactor coil when suctionpressure rises above or falls below setpoint.The LPCO control is closed at pressures above setpoint andopens at pressures below setpoint.SpecificationsCheck Procedure1. Connect manifold gauges at suction and dischargeaccess valves at the condensing unit.2. Set ICE/OFF/CLEAN switch to OFF.3. The liquid line solenoid valve will de-energize andthe suction pressure will begin to decrease. The low-pressure control will open at the listed specification.4. Use the manifold gauge set to increase suctionpressure. Feed refrigerant from the high side accessvalve to the low side access valve. Add refrigerant insmall increments to allow the low side pressure tobe monitored. The low pressure control will close atthe listed specification.Replace the LPCO control if it:• Will not close at the specified set point.• Does not open at the specified set point.! WarningIf discharge pressure exceeds 460 psig and theHPCO control does not cut out, set ICE/OFF/CLEANswitch to OFF to stop ice machine operation.Model Cut-In(Close)Cut-Out(Open)RFC2085RFC2385 22 psig+3 7 psig +3Revised 8/2003Downloaded from www.Manualslib.com manuals search engine