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

Page 72

8)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.

9)Evacuate the system, and charge it with refrigerant. For air-cooled and water-cooled models, see the nameplate for the required refrigerant charge. For remote air-cooled models, see the rating label inside the icemaker.

10)Attach the expansion valve bulb to the suction line in the same location as the previous bulb. The bulb should be between the 10 and 2 o'clock position on the tube. Be sure to secure the bulb with the clamp and holder and to insulate it.

11)Place the expansion valve cover in position.

12)Replace the panels in their correct positions.

13)Turn on the power supply.

D.Removal and Replacement of Hot Gas Valve or Liquid Line Valve

CAUTION

1.Always use a copper tube of the same diameter and length when replacing the valve lines; otherwise, performance may be affected.

2.Always replace the strainer when replacing the hot gas valve.

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

4.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.

5.When brazing, protect the valve body and drier by using wet cloths to prevent the valve body and drier from overheating. Do not allow the valve body or drier to exceed 250°F (121°C).

1)Turn off the power supply.

2)Remove the panels.

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

4)Remove the bolt and the solenoid.

5)Disconnect the valve. If replacing the hot gas valve, also remove the strainer.

6)Place the new valve and strainer (if applicable) in position.

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

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

9)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.

72

Image 72
Contents KM-901MAH KM-901MWH Hoshizaki AMERICA, INC Contents Page Page Important Safety Information Serious injuryIndicates important information about the use and care UnitSpecifications Icemaker 1a. KM-901MAH air-cooled Auxiliary Code T-0, U-01b. KM-901MAH air-cooled Auxiliary Code U-1 and Later 2a. KM-901MWH water-cooled Auxiliary Code T-0, U-0 Water Cooled Condenser2b. 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 Specifications Model URC-9FII. General Information Construction KM-901MAH air-cooledKM-901MWH water-cooled KM-901MRH/3 remote air-cooled Sequence of Operation Sequence Cycles and ShutdownControl Board Auxiliary Code T-0, U-0 Shutdown Control Board Auxiliary Code U-1 and LaterOFF Cycle at Shutdown Mechanical Bin Control Activation Control Board Sequence Flow Chart Sequence Flow ChartCycle Bin FullControl Board Auxiliary Code U-1 LaterMinute Harvest Cycle Freeze Cycle Pump-Out Cycle Fill CycleControl Board Control Board Layout Control BoardPart Number 2A3792-01 Harvest Backup Timer and Freeze Timer High Temperature SafetyLow Water Safety Maximum Water Supply Period 6 minutesLED Lights and Audible Alarm Safeties No. of Beeps Type of Alarm Every 3 secSequence Step Energized Time LEDs are On Components Min Max AvgControl Board Auxiliary Code U-1 and Later Controls and Adjustments Default Dip Switch SettingsHarvest Timer S4 dip switch 1 S4 Dip Switch S4 Dip Switch NoPump-Out Timer S4 dip switch 3 Pump-Out Frequency Control S4 dip switch 5S4 Dip Switch Setting Time seconds Inlet Bin Control Selector/Harvest Pump Timer S4 dip switch Factory Use S4 dip switchControl Board S4 Dip Switch Setting Bin Control Control Board S4 Dip Switch Setting Pump Motor Time secondsFreeze Timer S4 dip switch 9 Float Switch Control S5 dip switch 1 G Control BoardRefill Counter S5 dip switch 2 through 5 G Control Board S4 Dip Switch Setting Time MinutesFloat Switch Control SwitchBin Control ThermistorWater Pump Switch Discharge Line Wiring Diagrams ModelCooled-AirWater-Cooled Model PressureHigh* SwitchKM-901MAH air-cooled and KM-901MWH water-cooled PressureSwitch KM-901MRH remote air-cooledHigh KM-901MRH3 remote air-cooled Switch Cooled-WaterModel Cooled-AirModel High* PressureHigh Pressure Switch SwitchPressure Performance Data 912 8351480 1570KM-901MRH remote air-cooled KM-901MRH3 remote air-cooled IV. Service Diagnosis Diagnostic ProcedurePage OFF Control Board Check Shutdown Thermostatic Bin Control Auxiliary Code T-0, U-0Bin Control Check Control Correct LED Board Lighting SequenceMechanical Bin Control Check Mechanical Bin Control Cleaning Float Switch Check and Cleaning Float Switch CheckFloat Switch Cleaning Thermistor Check Diagnostic Charts Problem Possible Cause RemedyNo Ice Production Problem Possible Cause Remedy Problem Possible Cause Remedy Evaporator is Frozen Up Problem Possible Cause Remedy Low Ice Production Abnormal Ice Other Removal and Replacement of Components Service for Refrigerant LinesRefrigerant Recovery Brazing Evacuation and Recharge R-404ARemoval 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 VI. Cleaning and Maintenance Cleaning and Sanitizing InstructionsCleaning Procedure Sanitizing Procedure Following Cleaning Procedure Maintenance Preparing the Icemaker for Long StorageDrain the water tank