Manitowoc Ice STH003 manual Compressor Electrical Diagnostics, Check Resistance OHM Values

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COMPRESSOR ELECTRICAL DIAGNOSTICS

The compressor does not start or will trip repeatedly on overload.

CHECK RESISTANCE (OHM) VALUES

NOTE: Compressor windings can have very low ohm values. Use a properly calibrated meter.

Perform the resistance test after the compressor cools. The compressor dome should be cool enough to touch (below 120°F/49°C) to assure that the overload is closed and the resistance readings will be accurate.

SINGLE PHASE COMPRESSORS

1.Disconnect power from the condensing unit and remove the wires from the compressor terminals.

2.The resistance values between C and S and between C and R, when added together should equal the resistance value between S and R.

3.If the overload is open, there will be a resistance reading between S and R, and open readings between C and S and between C and R. Allow the compressor to cool, then check the readings again.

CHECK MOTOR WINDINGS TO GROUND

Check continuity between all three terminals and the compressor shell or copper refrigeration line. Scrape metal surface to get good contact. If continuity is present, the compressor windings are grounded and the compressor should be replaced.

To determine if the Compressor is seized check the amp draw while the compressor is trying to start.

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Contents CM050 CM Model Ice Machines Safety Notices Procedural Notices Read These Before Proceeding Personal Injury PotentialPotential Personal Injury Situation Table of Contents Liquid Line Thermistor Model Numbers CMS050A004Accessories Legs Manitowoc ICE Machine Cleaner and SanitizerDrain Pump MODEL/SERIAL Number Location General Owner Warranty Registration CardPage Manitowoc ICE, INC Location of ICE Machine InstallationHeat of Rejection Air Conditioning** Peak ICE Machine Heat of RejectionLevelers Legs Leveling the ICE MachineWater SERVICE/DRAINS Water Supply Water Inlet LinesDrain Connections Water Supply and Drain Line SIZING/CONNECTIONS Drain PumpGfci Requirements Electrical SpecificationsElectrical Requirements Voltage Minimum Circuit AmpacityComponent Identification Water Pump Evaporator Shutter Assembly Operational Checks BIN Thermostat AdjustmentPower Button Green Clean GreenSafety Timers ICE Machine Inspection Cleaning the CondenserAIR-COOLED Condenser Interior Cleaning and Sanitizing Place CLEANING/SANITIZING Procedure Interior Cleaning and Sanitizing GeneralPage Cleaning Procedure Page Page Removal of Parts for Cleaning and Sanitizing TOP Cover Water Shutters ICE Chute Sump Drain Overflow Tube Water Trough Spray BAR, Water Pump and Hose Spray BAR Disassembly SELF-CONTAINED AIR-COOLED ICE Machines Removal from SERVICE/LONG Term STORAGE/WINTERIZATION GeneralAutomatic Shut-Off Refrigeration System Start-UpFreeze HarvestSequence Energized Parts Chart SELF-CONTAINED ICE MachinesDiagnosing AN ICE Machine That will not RUN TroubleshootingPage ICE Machine will not Harvest ICE Quality is Poor Cubes are SHALLOW, Incomplete or White Freeze Cycle is LONG, LOW ICE Production ICE Machine Runs & no ICE is Produced Freeze Harvest Cycle Psig Beginning Freeze Cycle Discharge Pressure LOW Checklist Analyzing Suction Pressure Step ProcedureSuction Pressure High Checklist Problem Suction Pressure LOW Checklist ProblemDischarge Pressure HOT GAS Valve GeneralNormal Operation HOT GAS Valve Analysis Freeze cycle. If Function SpecificationsNo Ice on Ice on Bulb Result Check ProcedureFreeze Time Harvest Time Total Cycle Time Additional finishing time check Adjusting Finishing TimeLiquid Line Thermistor SM50 Resistance Chart TEMPERATURE/RESISTANCE ChartTotal System Refrigeration Charge Component Specifications Check Procedures Check Motor Windings to Ground Compressor Electrical DiagnosticsSingle Phase Compressors Check Resistance OHM ValuesCompressor Drawing High Amps Compressor Drawing Locked RotorRelay CapacitorPage Cycle Times Freeze Time + Harvest Time = Cycle Time Reclaim RecoverNew Product Specifications RecycleRefrigerant RE-USE Policy Page Connections Refrigerant Recovery/Evacuation/ChargingRecovery/Evacuation Charging Procedures Page System Contamination Cleanup General No symptoms or suspicion Normal Mild System Contamination Cleanup Procedure Change the vacuum pump oil Severe System Contamination Cleanup ProcedureFollow normal evacuation procedures Page FIG. a Pinching OFF Tubing Using Pinch Off ToolDo not disassemble valve Brazing Procedures for Danfoss Solenoid ValvesMAX F 700C Liquid Line Filter Drier Control Board Wiring Diagrams Tubing Schematic Manitowoc Ice, Inc