Low Ice Production | Hoshizaki KM-901MRH/3, KM-901MWH, KM-901MAH

Problem	Possible Cause		Remedy

[2]All ice formed on	l) Refrigerant	1. Low charge.	1. Check for leaks. Recover,
evaporator does not			repair, evacuate, and
fall into bin in harvest			recharge.
cycle. (continued)	m)Water Regulating Valve	1. Leaking by in harvest.	1. Check and replace.
	m)Water Regulating Valve	1. Leaking by in harvest.	1. Check and replace.
	(water-cooled model)

[3]Other.	a) Ice Cube Guide	1. Out of position.	1. Place in position.

	b) Thermostatic Bin	1. Bulb out of position.	1. Place in position.
	Control
	Control	2. Bad contacts.	2. Check for continuity and
		2. Bad contacts.	2. Check for continuity and
			replace. See "IV.C.1.
			Thermostatic Bin Control
			Check."
	c) Mechanical Bin Control	1. Movement restricted.	1. Check and free.
		2. Defective.	2. See "IV.C.2. Mechanical
			Bin Control Check and
			Cleaning."

3. Low Ice Production

Problem	Possible Cause			Remedy

[1] Freeze cycle time is	a) Inlet Water Valve		1. Diaphragm does not	1. Check for water leaks with
long.			close.	icemaker off.
	b) Float Switch		1. Float switch does not	1. Clean or replace. See "IV.
			move freely or switch	D. Float Switch Check and
			defective.	Cleaning."

	c) Evaporator		1. Scaled up.	1. Clean.

			2. Damaged.	2. Replace.

	d) Spray Tubes		1. Dirty.	1. Clean.

			2. Out of position.	2. Place in position.
	e) Pump Motor		1. RPM too slow.	1. See chart 1.[5].

	f)	Condenser (except	1. Air filter or condenser	1. Clean.
		water-cooled model)	clogged.

	g) Refrigerant Charge		1. Low charge.	1. Check for leaks. Recover,
				repair, evacuate, and
				recharge.

	h) Hot Gas Valve		1. Open.	1. Check and replace.
	i)	Expansion Valve	1. Bulb loose.	1. Secure bulb.

			2. Operating erratically.	2. Check and replace.

	j)	Compressor	1. Erratic or off.	1. See chart 1.[3].

	k) Condenser Water		1. Water regulating valve	1. Adjust or replace. See
		(water-cooled model)	set too high.	"V.J. Adjustment of Water
				Regulating Valve."

			2. Condenser water	2. Check and get
			pressure too low.	recommended pressure.
			3. Water temperature out	3. Correct to specification.
			of specification.

	l)	Liquid Line Valve	1. Erratic, sticking.	1. Check and replace.

	m)Headmaster (C.P.R.)		1. Bypassing.	1. Replace.
		(remote condenser
		unit)

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Image 65

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

Contents

KM-901MAH KM-901MWH Hoshizaki AMERICA, INC Contents Page Page Serious injury Important Safety InformationIndicates important information about the use and care Unit 1a. KM-901MAH air-cooled Auxiliary Code T-0, U-0 Specifications Icemaker 1b. KM-901MAH air-cooled Auxiliary Code U-1 and Later Water Cooled Condenser 2a. KM-901MWH water-cooled Auxiliary Code T-0, U-0 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 Model URC-9F Specifications KM-901MAH air-cooled II. General Information Construction KM-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 Shutdown OFF Cycle at Shutdown Mechanical Bin Control Activation Sequence Flow Chart Control Board Sequence Flow ChartCycle Bin Full Later Control Board Auxiliary Code U-1Minute Harvest Cycle Freeze Cycle Pump-Out Cycle Fill Cycle Control Board Control Board Control Board Layout Part Number 2A3792-01 High Temperature Safety Harvest Backup Timer and Freeze TimerLow Water Safety Maximum Water Supply Period 6 minutes No. of Beeps Type of Alarm Every 3 sec LED Lights and Audible Alarm SafetiesSequence Step Energized Time LEDs are On Components Min Max Avg Control 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 No S4 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 seconds Float 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 Minutes Control Switch Float SwitchBin Control 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 Cooled-AirModel High* Pressure Switch Cooled-WaterModel High Pressure Switch SwitchPressure Performance Data 835 9121480 1570 KM-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 Check Control Correct LED Board Lighting Sequence Bin Control Check Mechanical Bin Control Check Mechanical Bin Control Cleaning Float Switch Check Float Switch Check and Cleaning 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 Evacuation and Recharge R-404A Brazing 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 Cleaning and Sanitizing Instructions VI. Cleaning and Maintenance Cleaning Procedure Sanitizing Procedure Following Cleaning Procedure Preparing the Icemaker for Long Storage Maintenance Drain the water tank