Hoshizaki KM-901MRH/3, KM-901MWH Maximum Water Supply Period 6 minutes, High Temperature Safety

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2. Features

a)Maximum Water Supply Period - 6 minutes

"E" control board: The inlet water valve is open during harvest for 6 minutes or the length of harvest, whichever is shorter.

"G" control board: The inlet water valve is open during harvest for 6 minutes or the length of harvest minus 0 or 50 seconds (harvest pump timer (S4 dip switch 7)), whichever is shorter. For details, see "II.C.3.e) Bin Control Selector/Harvest Pump Timer

(S4 dip switch 7)."

b)Harvest Backup Timer and Freeze Timer

The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest cycle takes more than 20 minutes to complete. The control board signals this problem using 2 beeps every 3 seconds.

The freeze timer shuts down the icemaker if, for two cycles in a row, the freeze cycle takes longer than the time specified to complete. The control board signals this problem using 3 beeps every 3 seconds. The freeze timer is factory set using S4 dip switch 9 &10. For details, see "II.C.3.g) Freeze Timer (S4 dip switch 9 & 10)."

The "ALARM RESET" button on the control board must be pressed with power on to reset either of these safeties.

c)High Temperature Safety

The temperature of the suction line in the refrigeration circuit is limited by the high temperature safety. This protects the unit from excessively high temperatures. If the evaporator temperature reaches 127°F±7°F (53°C±4°C), the control board reads a

.8 kΩ signal from the thermistor and shuts down the icemaker.

The control board will signal this problem using 1 beep every 3 seconds. The "ALARM

RESET" button on the control board must be pressed with power on to reset the safety.

d)Low Water Safety

The control board checks the position of the float switch at the end of the initial 1-minute fill cycle and at the end of each harvest cycle. If the float switch is in the up position (electrical circuit closed), the control board changes to the next cycle. If the float switch is in the down position (electrical circuit open), the control board changes to additional

1-minute fill cycles until water enters the tank and closes the float switch. When the float switch closes, the control board changes to the next cycle. The unit will not start without adequate water in the tank. This serves as a low water safety to protect the water pump. For water-cooled model, if the condenser water supply is shut off, the unit is protected by the high-pressure switch.

e)High Voltage and Low Voltage Cut-outs

The maximum and minimum allowable supply voltages of this icemaker are limited by the high voltage and low voltage cut-outs. If miswiring (especially on single phase 3 wire models) causes excessive voltage (147Vac±5% or more), the high voltage cut-out shuts down the circuit in 3 seconds and the icemaker automatically stops. The control board will signal this problem using 7 beeps every 3 seconds.

The icemaker also automatically stops in cases of insufficient voltage (92Vac±5% or less). The control board will signal this problem using 6 beeps every 3 seconds. When the proper supply voltage is resumed, the icemaker automatically starts running again.

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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
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