Hoshizaki KM-901MWH, KM-901MAH, KM-901MRH/3 Bin Control, Float Switch, Thermistor, Control Switch

Page 36

D. Bin Control

1. Thermostatic Bin Control: Auxiliary Code T-0, U-0

CAUTION

When the ambient temperature is below 45°F (7°C), the thermostatic bin control switch opens and shuts down the icemaker even if the ice storage bin is empty. When the thermostat is set in the prohibited range, the icemaker operates continuously even if the ice storage bin is filled with ice. Setting in the prohibited range may result in severe damage to the icemaker.

The thermostatic bin control switch is a temperature controlled switch used to control the level of ice in the bin. It is in line with the power supply to the control switch.

The thermostatic bin control switch shuts down the unit within 10 seconds when ice contacts the thermostatic bulb, regardless of the cycle at activation. The thermostatic bin control is factory set, and generally no adjustment is required. However, adjustment may be needed in some conditions, particularly at higher altitude locations. For further details, see "IV.C.1. Thermostatic Bin Control Check."

2. Mechanical Bin Control: Auxiliary Code U-1 and Later

The mechanical bin control is a lever-actuated bin control switch used to control the level of ice in the bin. The mechanical bin control connects to the control board RED K4 connector. When the actuator paddle is not engaged (mechanical bin control switch closed; control board green "BC CLOSED" LED on), the unit produces ice. When the actuator paddle is engaged (mechanical bin control switch open; control board yellow "BC OPEN" LED on), the unit shuts down as outlined in the table below.

Cycle at

Shutdown

Mechanical Bin

 

Control Activation

 

 

 

Fill Cycle

15 seconds after activation.

 

 

Harvest Cycle

At the end of the harvest cycle, or up to 15 seconds into the freeze cycle if

 

activated at the end of the harvest cycle.

 

 

Freeze Cycle

15 seconds after activation if activated at least 15 seconds before the 5-minute

 

short cycle protection timer expires. Otherwise, at the end of the next harvest

 

cycle.

E. Float Switch

The float switch is used to determine that there is sufficient water in the tank after the 1‑minute fill cycle and after each harvest cycle. The float switch is also used to determine that the appropriate volume of water has been converted into ice before switching out of the freeze cycle. No adjustment is required.

F. Thermistor

The thermistor is used as a harvest control sensor. The thermistor's resistance varies depending on the suction line temperature. The control board monitors the resistance to start the harvest timer. No adjustment is required.

G. Control Switch

The control switch has three positions: "OFF" for power off, "ICE" for icemaking, and "WASH" to activate the water pump when cleaning and sanitizing.

36

Page 35 Page 37
Image 36
Page 35 Page 37
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
Top Page Image Contents