Problem Possible Cause Remedy | Hoshizaki KM-901MRH/3, KM-901MWH

	Problem	Possible Cause		Remedy

	[3] Compressor will	a) Magnetic Contactor	1. Bad contacts.	1. Check for continuity and
	not start or stops			replace.
	operating.		2. Coil winding open.	2. Replace.
			2. Coil winding open.	2. Replace.

		b) Start Capacitor or Run	1. Defective.	1. Replace.
		Capacitor

		c) Internal Overload	1. Loose terminal.	1. Tighten or replace.
		Protector Open (check
		Protector Open (check	2. Voltage.	2. Check and correct.
		1 through 3 to the right	2. Voltage.	2. Check and correct.
		and d through f below)	3. Dirty condenser.	3. Clean.

		d) Starter	1. Bad contacts.	1. Check and replace.
			2. Coil winding open.	2. Replace.
		e) Compressor	1. Power supply not	1. Refer to nameplate and
			within specifications.	correct.

			2. Wiring to compressor.	2. Check for loose connection
				or open, and replace.

			3. Defective.	3. Replace.

			4. Protector tripped.	4. Reduce temperature.
		f) Control Board	1. No power to contactor.	1. See "IV.B. Control Board
				Check."

	[4] Water continues to	a) Water Pressure	1. Too high.	1. Reduce.
	be supplied in freeze
	be supplied in freeze	b) Inlet Water Valve	1. Diaphragm does not	1. Check for water leaks with
	cycle.		close.	icemaker off.
			close.	icemaker off.

		c) Control Board	1. Defective.	1. See "IV.B. Control Board
				Check."
	[5] Pump motor will not	a) Pump Motor	1. Motor winding open.	1. Replace.
	start.
	start.		2. Bearing worn out.	2. Replace.
			2. Bearing worn out.	2. Replace.

			3. Wiring to pump motor.	3. Check for loose connection
				or open, and replace.

			4. Defective capacitor.	4. Replace.
			5. Defective or bound	5. Replace and clean.
			impeller.

			6. Mechanical seal worn	6. Check and replace.
			out.

		b) Control Board	1. Defective.	1. See "IV.B. Control Board
				Check."

		c) Control Switch	1. Bad contacts.	1. Replace.
	[6] Freeze cycle time is	a) Pump-Out Check Valve	1. Leaking by.	1. Clean or replace.
	too short.
	too short.	b) Float Switch	1. Dirty or erratic	1. Clean or replace. See "IV.
		b) Float Switch	1. Dirty or erratic	1. Clean or replace. See "IV.
			operation.	D. Float Switch Check and
				Cleaning."

		c) Control Board	1. Defective.	1. See "IV.B. Control Board
				Check."

		d) Water System	1. Water leaks.	1. Check connections for
				water leaks and repair.

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Hoshizaki KM-901MRH/3, KM-901MWH, KM-901MAH service manual Problem Possible Cause Remedy

Contents

KM-901MAH KM-901MWH Hoshizaki AMERICA, INC Contents Page Page Indicates important information about the use and care Important Safety InformationSerious injury Unit Specifications Icemaker 1a. KM-901MAH air-cooled Auxiliary Code T-0, U-0 1b. KM-901MAH air-cooled Auxiliary Code U-1 and Later 2a. KM-901MWH water-cooled Auxiliary Code T-0, U-0 Water Cooled Condenser 2b. 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-9F II. General Information Construction KM-901MAH air-cooled KM-901MWH water-cooled KM-901MRH/3 remote air-cooled Control Board Auxiliary Code T-0, U-0 Sequence of OperationSequence Cycles and Shutdown Shutdown Control Board Auxiliary Code U-1 and Later OFF Cycle at Shutdown Mechanical Bin Control Activation Cycle Control Board Sequence Flow ChartSequence Flow Chart Bin Full Minute Harvest Cycle Freeze Cycle Pump-Out Cycle Control Board Auxiliary Code U-1Later Fill Cycle Control Board Control Board Layout Control Board Part Number 2A3792-01 Low Water Safety Harvest Backup Timer and Freeze TimerHigh Temperature Safety Maximum Water Supply Period 6 minutes Sequence Step LED Lights and Audible Alarm SafetiesNo. of Beeps Type of Alarm Every 3 sec Energized Time LEDs are On Components Min Max Avg Control Board Auxiliary Code U-1 and Later Harvest Timer S4 dip switch 1 Controls and AdjustmentsDefault Dip Switch Settings S4 Dip Switch S4 Dip Switch No S4 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 Bin Control Bin Control Selector/Harvest Pump Timer S4 dip switchFactory Use S4 dip switch Control Board S4 Dip Switch Setting Pump Motor Time seconds Refill Counter S5 dip switch 2 through 5 G Control Board Freeze Timer S4 dip switch 9Float Switch Control S5 dip switch 1 G Control Board S4 Dip Switch Setting Time Minutes Bin Control Float SwitchControl Switch Thermistor Water 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 Switch Cooled-WaterModel Cooled-AirModel High* Pressure High Pressure Switch SwitchPressure Performance Data 1480 912835 1570 KM-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-0 Bin Control Check Control Correct LED Board Lighting Sequence Mechanical Bin Control Check Mechanical Bin Control Cleaning Float Switch Check and Cleaning Float Switch Check Float 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 Brazing Evacuation and Recharge R-404A Removal 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 Instructions Cleaning Procedure Sanitizing Procedure Following Cleaning Procedure Maintenance Preparing the Icemaker for Long Storage Drain the water tank