Hoshizaki KM-901MRH/3, KM-901MWH, KM-901MAH service manual Thermistor Check

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E. Thermistor Check

To check thermistor resistance, follow the steps below.

1)Turn off the power supply.

2)Remove the front panel, then move the control switch to the "OFF" position.

3)Remove the control box cover.

4)Remove the thermistor. See "V.L. Removal and Replacement of Thermistor."

5)Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes.

6)Remove the white thermistor connector from the control board WHITE K3 connector and check the resistance between thermistor leads. Normal reading is within 4.7 to 6.2 kΩ. If outside the normal reading, replace the thermistor. If inside the normal reading, continue to the next step.

7)Replace the thermistor in its correct position. See "V.L. Removal and Replacement of Thermistor."

8)Reconnect the white thermistor connector to the control board WHITE K3 connector.

9)Replace the control box cover in its correct position, then turn on the power supply.

10)Move the control switch to the "ICE" position.

11)Once the harvest cycle starts, begin timing the harvest cycle.

12)The harvest timer should expire and terminate the harvest cycle within 2 to 3 minutes. If the harvest timer does not expire and terminate the harvest cycle, the harvest timer is bad and the control board should be replaced. See "V.P. Removal and Replacement of Control Board."

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Contents KM-901MAH KM-901MWH Hoshizaki AMERICA, INC Contents Page Page Unit Important Safety InformationSerious injury Indicates important information about the use and care1a. KM-901MAH air-cooled Auxiliary Code T-0, U-0 Specifications Icemaker1b. KM-901MAH air-cooled Auxiliary Code U-1 and Later Water Cooled Condenser 2a. KM-901MWH water-cooled Auxiliary Code T-0, U-02b. KM-901MWH water-cooled Auxiliary Code U-1 and Later 3a. KM-901MRH remote air-cooled Auxiliary Code T-0, U-0 3b. KM-901MRH remote air-cooled Auxiliary Code U-1 and Later 4a. KM-901MRH3 remote air-cooled Auxiliary Code T-0, U-0 4b. KM-901MRH remote air-cooled Auxiliary Code U-1 and Later Condenser Unit Model URC-9F SpecificationsKM-901MAH air-cooled II. General Information ConstructionKM-901MWH water-cooled KM-901MRH/3 remote air-cooled Control Board Auxiliary Code T-0, U-0 Sequence of OperationSequence Cycles and Shutdown Control Board Auxiliary Code U-1 and Later ShutdownOFF Cycle at Shutdown Mechanical Bin Control Activation Bin Full Control Board Sequence Flow ChartSequence Flow Chart CycleFill Cycle Control Board Auxiliary Code U-1Later Minute Harvest Cycle Freeze Cycle Pump-Out CycleControl Board Control Board Control Board LayoutPart Number 2A3792-01 Maximum Water Supply Period 6 minutes Harvest Backup Timer and Freeze TimerHigh Temperature Safety Low Water SafetyEnergized Time LEDs are On Components Min Max Avg LED Lights and Audible Alarm SafetiesNo. of Beeps Type of Alarm Every 3 sec Sequence StepControl Board Auxiliary Code U-1 and Later S4 Dip Switch S4 Dip Switch No Controls and AdjustmentsDefault Dip Switch Settings Harvest Timer S4 dip switch 1S4 Dip Switch Setting Time seconds Inlet Pump-Out Timer S4 dip switch 3Pump-Out Frequency Control S4 dip switch 5 Control Board S4 Dip Switch Setting Pump Motor Time seconds Bin Control Selector/Harvest Pump Timer S4 dip switchFactory Use S4 dip switch Control Board S4 Dip Switch Setting Bin ControlS4 Dip Switch Setting Time Minutes Freeze Timer S4 dip switch 9Float Switch Control S5 dip switch 1 G Control Board Refill Counter S5 dip switch 2 through 5 G Control BoardThermistor Float SwitchControl Switch Bin ControlWater Pump Switch Discharge Line KM-901MAH air-cooled and KM-901MWH water-cooled Wiring DiagramsModelCooled-AirWater-Cooled Model PressureHigh* Switch High PressureSwitchKM-901MRH remote air-cooled KM-901MRH3 remote air-cooled Cooled-AirModel High* Pressure Switch Cooled-WaterModelHigh Pressure Switch SwitchPressure Performance Data 1570 912835 1480KM-901MRH remote air-cooled KM-901MRH3 remote air-cooled Diagnostic Procedure IV. Service DiagnosisPage OFF Shutdown Thermostatic Bin Control Auxiliary Code T-0, U-0 Control Board CheckControl Correct LED Board Lighting Sequence Bin Control CheckMechanical Bin Control Check Mechanical Bin Control Cleaning Float Switch Check Float Switch Check and CleaningFloat Switch Cleaning Thermistor Check No Ice Production Diagnostic ChartsProblem Possible Cause Remedy Problem Possible Cause Remedy Problem Possible Cause Remedy Evaporator is Frozen Up Problem Possible Cause Remedy Low Ice Production Abnormal Ice Other Refrigerant Recovery Removal and Replacement of ComponentsService for Refrigerant Lines Evacuation and Recharge R-404A BrazingRemoval and Replacement of Compressor Removal and Replacement of Expansion Valve Page Removal and Replacement of Evaporator Removal and Replacement of Air-Cooled Condenser Removal and Replacement of Water-Cooled Condenser Removal and Replacement of Remote Air-Cooled Condenser Page Adjustment of Water Regulating Valve water-cooled model Removal and Replacement of Thermistor Removal and Replacement of Inlet Water Valve Removal and Replacement of Pump Motor Removal and Replacement of Control Board Cleaning and Sanitizing Instructions VI. Cleaning and MaintenanceCleaning Procedure Sanitizing Procedure Following Cleaning Procedure Preparing the Icemaker for Long Storage MaintenanceDrain the water tank