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

Page 77

I. Removal and Replacement of Water Regulating Valve (water-cooled

model)

CAUTION

1.Always install a new drier every time the sealed refrigeration system is opened.

2.Do not replace the drier until after all other repair or replacement has been made. Install the new drier with the arrow on the drier in the direction of the refrigerant flow.

3.When brazing, protect the drier by using a wet cloth to prevent the drier from overheating. Do not allow the drier to exceed 250°F (121°C).

1)Turn off the power supply.

2)Remove the panels.

3)Close the condenser water supply line shut-off valve. If connected to a closed loop water supply, also close the condenser return outlet shut-off valve.

4)Open the condenser water supply line drain valve. If connected to a closed loop water supply, also open the condenser return outlet drain valve.

5)Attach a compressed air or carbon dioxide supply to the condenser water supply line drain valve.

6)Open the water regulating valve by using a screwdriver to pry up on the spring retainer underneath the spring. While holding the valve open, blow out the condenser using the compressed air or carbon dioxide supply until water stops coming out.

7)Recover the refrigerant and store it in an approved container.

8)Disconnect the capillary tube at the condenser outlet.

9)Disconnect the flare-connections of the valve.

10)Remove the screws and the valve from the bracket.

11)Install the new valve.

12)Remove the drier, then place the new drier in position.

13)Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.

14)Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of refrigerant to the system (if using an electronic leak detector), and then raise the pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with pressurized air for leak testing.

15)Evacuate the system, and charge it with refrigerant. See the nameplate for the required refrigerant charge.

16)Connect the flare-connections.

17)Close the drain valve(s). Open the condenser water supply line shut-off valve. If connected to a closed loop water supply, also open the condenser return outlet shut-off valve.

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Contents KM-901MAH KM-901MWH Hoshizaki AMERICA, INC Contents Page Page Serious injury Important Safety InformationIndicates important information about the use and care Unit1a. 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 Sequence Flow Chart Control Board Sequence Flow ChartCycle Bin FullLater Control Board Auxiliary Code U-1Minute Harvest Cycle Freeze Cycle Pump-Out Cycle Fill CycleControl Board Control Board Control Board LayoutPart Number 2A3792-01 High Temperature Safety Harvest Backup Timer and Freeze TimerLow Water Safety Maximum Water Supply Period 6 minutesNo. of Beeps Type of Alarm Every 3 sec LED Lights and Audible Alarm SafetiesSequence Step Energized Time LEDs are On Components Min Max AvgControl Board Auxiliary Code U-1 and Later Default Dip Switch Settings Controls and AdjustmentsHarvest Timer S4 dip switch 1 S4 Dip Switch S4 Dip Switch NoS4 Dip Switch Setting Time seconds Inlet Pump-Out Timer S4 dip switch 3Pump-Out Frequency Control S4 dip switch 5 Factory Use S4 dip switch Bin Control Selector/Harvest Pump Timer S4 dip switchControl Board S4 Dip Switch Setting Bin Control Control Board S4 Dip Switch Setting Pump Motor Time secondsFloat Switch Control S5 dip switch 1 G Control Board Freeze Timer S4 dip switch 9Refill Counter S5 dip switch 2 through 5 G Control Board S4 Dip Switch Setting Time MinutesControl Switch Float SwitchBin Control ThermistorWater 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 835 9121480 1570KM-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