Hoshizaki KM-901MAH, KM-901MWH, KM-901MRH/3 service manual Part Number 2A3792-01

Page 28

b) "G" Control Board: Auxiliary Code U-1 and Later

"G" Control Board

Bin Control Switch	"ALARM RESET" Button	S4 Dip
Closed LED (green)	"ALARM RESET" Button	Switch
(on continuously
in thermostatic bin
control application)
Bin Control Switch
Open LED (yellow)
(mechanical bin control
application only)
Part Number
Alarm Buzzer
Power LED (red)
(lights when
power is supplied
to the control board)
Relay LEDs (4)
(indicate which
relays are energized
as listed below)
LED 2 (X2 Relay)
Hot Gas Valve (HGV)
Fan Motor (FM)
(FM off when LED on)
Liquid Line Valve (LLV)
LED 3 (X3 Relay)
Pump Motor (PM)
(on at pump-out,
harvest (if applicable))
LED 4 (X4 Relay)
Inlet Water Valve (WV)
LED 1 (X1 Relay)
Compressor (Comp),
Fan Motor-Remote
(FMR)

K2 Connector

Transformer

"OUTPUT TEST" Button

(used to test relays on control board)

WHITE K3 Connector Harvest Control (thermistor)

RED K4 Connector Mechanical Bin Control or K4 Jumper (thermostatic bin control application)

S5 Dip Switch

BLACK K5 Connector Float Switch

Label

(control board revision level indicated on label on side of relay)

K1 Ten-Pin Connector

Pins #1 through #10

#1, 9 Magnetic Contactor

#2 Hot Gas Valve (HGV)

#3 Fan Motor (FM),

Liquid Line Valve (LLV)

#4 Pump Motor (icemaking)

#5 Pump Motor (pump-out,

harvest (if applicable))

#6 Inlet Water Valve (WV)

#7, 10 Component Power

Supply

#8 Open

Switch for "C" control board and "ALPINE" control board (service control board only)

"G" Control Board

Part Number 2A3792-01

28

Image 28

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 Cycles and Shutdown Sequence of OperationControl 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 Frequency Control S4 dip switch 5 Pump-Out Timer S4 dip switch 3S4 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 ModelCooled-AirWater-Cooled Model PressureHigh* Switch Wiring DiagramsKM-901MAH air-cooled and KM-901MWH water-cooled KM-901MRH remote air-cooled PressureSwitchHigh 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 Problem Possible Cause Remedy Diagnostic ChartsNo Ice Production Problem Possible Cause Remedy Problem Possible Cause Remedy Evaporator is Frozen Up Problem Possible Cause Remedy Low Ice Production Abnormal Ice Other Service for Refrigerant Lines Removal and Replacement of ComponentsRefrigerant 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