Manitowoc Ice S1800 service manual HOW the Probe Works, Harvest Light, Freeze Time LOCK-IN Feature

Page 60

Electrical System

Section 6

 

 

Ice Thickness Probe (Harvest Initiation)

HOW THE PROBE WORKS

Manitowoc’s electronic sensing circuit does not rely on refrigerant pressure, evaporator temperature, water levels or timers to produce consistent ice formation.

As ice forms on the evaporator, water (not ice) contacts the ice thickness probe. After the water completes this circuit across the probe continuously for 6-10 seconds, a harvest cycle is initiated.

SV3135

Ice Thickness Probe

HARVEST LIGHT

This light’s function is to be on as water contacts the ice thickness probe during the freeze cycle, and remain on throughout the entire harvest cycle. The light will flicker as water splashes on the probes.

FREEZE TIME LOCK-IN FEATURE

The ice machine control system incorporates a freeze time lock-in feature. This prevents the ice machine from short cycling in and out of harvest.

The control board locks the ice machine in the freeze cycle for six minutes. If water contacts the ice thickness probe during these six minutes, the harvest light will come on (to indicate that water is in contact with the probe), but the ice machine will stay in the freeze cycle. After the six minutes are up, a harvest cycle is initiated. This is important to remember when performing diagnostic procedures on the ice thickness control circuitry.

To allow the service technician to initiate a harvest cycle without delay, this feature is not used on the first cycle after moving the toggle switch OFF and back to ICE.

MAXIMUM FREEZE TIME

The control system includes a built-in safety which will automatically cycle the ice machine into harvest after 60 minutes in the freeze cycle.

ICE THICKNESS CHECK

The ice thickness probe is factory-set to maintain the ice bridge thickness at 1/8" (.32 cm).

NOTE: Make sure the water curtain is in place when performing this check. It prevents water from splashing out of the water trough.

1.Inspect the bridge connecting the cubes. It should be about 1/8" (.32 cm) thick.

2.If adjustment is necessary, turn the ice thickness probe adjustment screw clockwise to increase bridge thickness, or counterclockwise to decrease bridge thickness. Set a 1/4” gap between the ice thickness probe and evaporator as a starting point. Then adjust to achieve a 1/8” bridge thickness.

NOTE: The starting point before final adjustment is approximately a 3/16 inch gap.

ADJUSTING SCREW

1/8” ICE BRIDGE THICKNESS

SV3132

Ice Thickness Check

Make sure the ice thickness probe wire and the bracket do not restrict movement of the probe.

Ice Thickness Probe Cleaning

1.Mix a solution of Manitowoc ice machine cleaner and water (2 ounces of cleaner to 16 ounces of water) in a container.

2.Soak ice thickness probe in container of cleaner/ water solution while disassembling and cleaning water circuit components (soak ice thickness probe for 10 minutes or longer).

3.Clean all ice thickness probe surfaces including all plastic parts (do not use abrasives). Verify the ice thickness probe cavity is clean. Thoroughly rinse ice thickness probe (including cavity) with clean water, then dry completely. Incomplete rinsing and drying of the ice thickness probe can cause premature harvest.

4.Reinstall ice thickness probe, then sanitize all ice machine and bin/dispenser interior surfaces.

6-22

Part Number 80-1634-3

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Page 59 Page 61
Contents Service Manual Read These Before Proceeding Personal Injury PotentialTable of Contents Table of Contents Section Ice Machine Operation Section MaintenanceSection 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 StepMaintenance Section Sanitizing ProcedureSolution Type Water Mixed With Sanitizer Removal of Parts for CLEANING/SANITIZING Solution Type Water Mixed WithWater Curtain Water Curtain Removal Ice Thickness ProbeIce Thickness Probe Removal Water Distribution Tube Water TroughWater Distribution Tube Removal Water Level Probe Water PumpWater Pump Removal Dump Valve Disassembly Water Dump ValveEvaporator Tray Removal Drain Line Check ValveWater Inlet Valve Maintenance Section Removal from Service/Winterization Pry Open the Water Regulating Valve AUCS→ AccessorySELF-CONTAINED WATER-COOLED ICE Machines Checklist Problem Possible Cause To CorrectBefore Calling For Service Section Safety Limit FeatureEnergized Parts Charts Section Electrical SystemSELF-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 5 Seconds Toggle Switch Refrigeration System START-UPSelf-Contained Refrigeration System Start-Up Electrical System Section Freeze SequencePRE-CHILL Self-Contained Pre-Chill Self-Contained ModelsToggle Switch Bin Switch Control Board Relays FreezeSelf-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 SeizedPtcr Diagnostics What is a PTCR?Compressor 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 Check ICE/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 CircuitryProblem Water Trough Overfilling During Freeze Cycle Diagnosing Water Level Control CircuitryWait 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 minutesINSTALLATION/VISUAL Inspection Checklist Water System ChecklistPossible Problem Corrective Action ICE Formation Pattern Extremely Thin at Evaporator OutletNormal Ice Formation Extremely Thin at Evaporator Inlet No Ice FormationSafety Limits Safety Limit IndicationAnalyzing 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 Temperature Check General Harvest Valve AnalysisFindings 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 NumberTotal System Refrigerant Charges Series Version Charge S1800M48 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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