Manitowoc Ice S1800 service manual Compressor Electrical Diagnostics, Check Resistance Ohm Values

Page 52

Electrical System

Section 6

 

 

COMPRESSOR ELECTRICAL DIAGNOSTICS

The compressor will 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 cuber 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.

THREE PHASE COMPRESSORS

1.Disconnect power from the cuber and remove the wires from the compressor terminals.

2.The resistance values between L1 and L2, between L2 and L3, and between L3 and L1 should all be equal.

3.If the overload is open, there will be open readings between L1 and L2, between L2 and L3, and between L3 and L1. 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.

Determine if the Compressor is Seized

Check the amp draw while the compressor is trying to start.

COMPRESSOR DRAWING LOCKED ROTOR

The two likely causes of this are:

•Defective starting component

•Mechanically seized compressor To determine which you have:

1.Install high and low side gauges.

2.Try to start the compressor.

3.Watch the pressures closely.

A.If the pressures do not move, the compressor is seized. Replace the compressor.

B.If the pressures move, the compressor is turning slowly and is not seized. Check the capacitors and start relay.

COMPRESSOR DRAWING HIGH AMPS

The continuous amperage draw on start-up should not be near the maximum fuse size indicated on the serial tag.

Diagnosing Capacitors

•If the compressor attempts to start, or hums and trips the overload protector, check the starting components before replacing the compressor.

•Visual evidence of capacitor failure can include a bulged terminal end or a ruptured membrane. Do not assume a capacitor is good if no visual evidence is present.

•A good test is to install a known good substitute capacitor.

•Use a capacitor tester when checking a suspect capacitor. Clip the bleed resistor off the capacitor terminals before testing.

6-14

Part Number 80-1634-3

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Contents Service Manual Read These Before Proceeding Personal Injury PotentialTable of Contents Section Maintenance Table of Contents Section Ice Machine OperationSection Before Calling For Service Table of Contents Section Electrical System Section Refrigeration SystemTable of Contents How to Read a Model Number Model NumbersIce Cube Sizes Self-Contained Water-CooledGeneral Information Section Accessories Section General Information Model/Serial Number Location Model/Serial Number LocationWarranty Coverage Ice Machine Dimensions Width, Depth, and Height DimensionsElectrical and AuCS Dimensions GeneralInstallation Instructions Section Location of Ice Machine Ice Machine Heat of RejectionS1800M Water-Cooled Series Heat of Rejection Ice Machine Air ConditioningSection Installation Instructions Electrical Service VoltageMinimum Circuit Ampacity Electrical RequirementsFor United Kingdom Only Self Contained ICE Machine 115/1/60 or 208-230/1/60Self Contained ICE Machine 208-230/3/60 Self Contained ICE Machine 230/1/50Cooling Tower Applications Water SupplyWater Inlet Lines Drain ConnectionsInstallation Instructions Section Typical Water Supply Drain InstallationWater Supply and Drain Line SIZING/CONNECTIONS CondenserSection Installation Instructions Installation Check List AuCS Automatic Cleaning System Potential Personal Injury SituationSection Ice Machine Operation Component IdentificationIce Machine Operation Section Sequence Of Operation Initial START-UP or START-UP After Automatic SHUT-OFFSafety Timers Harvest Sequence 5. Water PurgeHarvest Automatic SHUT-OFF 7. Automatic Shut-OffIce Machine Operation Section Operational Checks Water LevelICE Thickness Check Ice Thickness CheckWater Purge Adjustment Harvest Sequence Water PurgeIce Machine Operation Section This page Intentionally Left BlankExterior Cleaning Ice Machine InspectionWater-Cooled Condenser Water Regulating Valve AlphaSan→Maintenance Section Guardian InstallationSachet Replacement Frequency Sachet Replacement ProcedureSection Maintenance Interior Cleaning and Sanitizing Cleaning ProcedureModel Amount of Cleaner StepSanitizing Procedure Maintenance SectionSolution Type Water Mixed With Sanitizer Removal of Parts for CLEANING/SANITIZING Solution Type Water Mixed WithWater Curtain Removal Ice Thickness Probe Water CurtainIce Thickness Probe Removal Water Trough Water Distribution TubeWater Distribution Tube Removal Water Pump Water Level ProbeWater Pump Removal Dump Valve Disassembly Water Dump ValveEvaporator Tray Removal Drain Line Check ValveWater Inlet Valve Pry Open the Water Regulating Valve AUCS→ Accessory Maintenance Section Removal from Service/WinterizationSELF-CONTAINED WATER-COOLED ICE Machines Checklist Problem Possible Cause To CorrectBefore Calling For Service Section Safety Limit FeatureSection Electrical System Energized Parts ChartsSELF-CONTAINED WATER-COOLED Models SELF-CONTAINED Models Initial Start-Up or Start-Up After Automatic Shut-OffWater Purge Self-Contained Water PurgeRefrigeration System START-UP Refrigeration System Start Up 5 Seconds Toggle SwitchSelf-Contained Refrigeration System Start-Up Electrical System Section Freeze SequencePRE-CHILL Self-Contained Pre-Chill Self-Contained ModelsFreeze Toggle Switch Bin Switch Control Board RelaysSelf-Contained Freeze Self-Contained Models Harvest Sequence Harvest Automatic SHUT-OFF Automatic Shut-OffSelf-Contained Automatic Shut-Off Section Electrical System Wiring Diagrams Wiring Diagram LegendS1800 SELF-CONTAINED 1 Phase Control BoardS1800 SELF-CONTAINED 3 Phase Specifications Check ProcedureBIN Switch Main FuseSymptoms Diagnostic AidsContinuity Test Water Curtain Removal NotesCompressor Electrical Diagnostics Check Resistance Ohm ValuesCheck Motor Windings to Ground Determine if the Compressor is SeizedWhat is a PTCR? Ptcr DiagnosticsCompressor Start Sequence Troubleshooting PTCR’s WHY a Good Ptcr MAY Fail To Start the CompressorModel Automatic Shut-Off and Restart During Start-Up First .25 1.0 SecondsChecking the Ptcr Manitowoc PtcrModel Manitowoc Cera-Mite Room Part NumberDiagnosing Start Components CapacitorRelay Relay Operation CheckICE/OFF/CLEAN Toggle Switch Switch Setting Terminals Ohm ReadingElectronic Control Board Control BoardSafety Limits InputsFreeze Time LOCK-IN Feature Ice Thickness Probe CleaningHOW the Probe Works Harvest LightDiagnosing ICE Thickness Control Circuitry Monitoring of Harvest Light CorrectionWater Inlet Valve Safety SHUT-OFF Electrical System Section Water Level Control CircuitryWater Level Probe Light Freeze Cycle CircuitryDiagnosing Water Level Control Circuitry Problem Water Trough Overfilling During Freeze CycleWait until the freeze cycle starts On or OFF Step Check Self Contained 1 Phase with Terminal Board SELF-CONTAINED Water -COOLED Models Freeze Cycle Refrigeration SequenceRefrigeration System Section S1800 SELF-CONTAINED Tubing Schematic General Before Beginning Service Weights are in poundsICE Production Check Times are in minutesWater System Checklist INSTALLATION/VISUAL Inspection ChecklistPossible Problem Corrective Action Extremely Thin at Evaporator Outlet ICE Formation PatternNormal Ice Formation Extremely Thin at Evaporator Inlet No Ice FormationSafety Limit Indication Safety LimitsAnalyzing Why Safety Limits May Stop the Ice Machine Safety Limit Notes Possible Cause Check/CorrectSection Refrigeration System Procedure Freeze Cycle Discharge Pressure High ChecklistFreeze Cycle Discharge Pressure Low Checklist Analyzing Discharge Pressure During Freeze or Harvest CycleStep Example Using SY1004A Model Ice Machine Analyzing Suction Pressure During Freeze CycleFreeze Cycle Suction Pressure High Checklist Freeze Cycle Suction Pressure Low ChecklistHarvest Valve Analysis Harvest Valve Temperature Check GeneralFindings Comments Discharge Line Temperature Analysis General Final Analysis Column 1 Harvest Valve LeakingColumn 2 LOW CHARGE/TXV Starving Column 3 TXV FloodingRefrigeration System Operational Analysis Tables Models Dual Expansion Valve Ice Machine Model NumberHigh Pressure CUT-OUT Hpco Control S1800 Series Self-Contained Water-Cooled Cycle TimesHour Ice Production Operating PressuresSELF-CONTAINED RECOVERY/EVACUATION ConnectionsSelf-Contained Charging Procedures Charging ConnectionsSystem Contamination CLEAN-UP Determining Severity Of ContaminationMild System Contamination Cleanup Procedure Severe System Contamination Cleanup ProcedureSection Refrigeration System 10. Using Pinch-Off Tool FILTER-DRIERS Drier End Part Model Connection Size NumberSeries Version Charge S1800M Total System Refrigerant Charges48 oz Recover New Product SpecificationsRefrigerant Definitions RecycleRecovered or Recycled Refrigerant Refrigerant RE-USE PolicyNew Refrigerant Reclaimed RefrigerantHFC Refrigerant Questions and Answers This page Intentionally Left Blank Page Attend a Manitowoc Factory Service School
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