Hoshizaki KM-901MAH, KM-901MWH, KM-901MRH/3 service manual Off

Page 52

5)Freeze Cycle – LED 1 is on. Comp and FMR remain energized, PM, LLV, and FM energize. WV and HGV de‑energize. The unit is held in freeze by a 5-minute short cycle protection timer (CB will not accept a signal from F/S). After the

5‑minute short cycle protection timer expires, CB turns freeze termination over to F/S. Diagnosis: During the first 5 minutes of freeze, confirm that the evaporator temperature drops. After 5 minutes in freeze, disconnect black F/S connector from CB BLACK K5 connector. If the evaporator is not cold, check to see if HGV is still open or if TXV is not opening properly, if WV is continuing to fill the reservoir, if there are improper unit pressures, an inoperative Comp, or an inoperative HM. The unit should switch out of the freeze cycle ("G" CB - 15 second delay after F/S opens before terminating the freeze cycle). If the unit switches out of freeze with F/S removed, but would previously not switch out of freeze with F/S connected (long freeze - 3 beep alarm), F/S may be sticking. To check and clean F/S, see "IV.D. Float Switch Check and Cleaning." If the unit remains in freeze (longer than 15 seconds on "G" CB)

after disconnecting the black F/S connector, replace CB. See "V.P. Removal and Replacement of Control Board."

Note: Normal freeze cycle will last 20 to 40 minutes depending on model and conditions. Cycle times and pressures should follow performance data provided in this manual. See "III.C. Performance Data."

6)Pump-Out Cycle – (10/20 second pump-out) – LEDs 1, 3, and 2 are on. LED 4 is on when S4 dip switch 3 & 4 are set to 3 off and 4 on. Comp and FMR remain energized, HGV energizes. WV energizes if S4 dip switch 3 off and 4 on. LLV and FM de‑energize. PM stops for 2 seconds, then reverses for 10/20 seconds depending on pump‑out timer S4 dip switch 3 & 4 setting. When the pump-out timer expires, the pump-out is complete. The pump-out frequency control is factory set for every 10th cycle, and generally no adjustment is required. However, where water quality is bad and the icemaker needs a pump‑out more often, the pump‑out frequency can be adjusted. The pump-out frequency control (S4 dip switch 5 & 6) can be set to have

a pump-out occur every cycle, or every 2, 5, or 10 cycles. For details, see "II.C.3.d) Pump‑Out Frequency Control (S4 dip switch 5 & 6)."

Timing of the first pump-out is dependent on CB. "E" CB first pump‑out is after the first freeze cycle. "G" CB first pump-out is determined by S4 dip switch 5 & 6. See the table below.

"E" & "G" Control Board Settings

1st Pump-Out

 

 

 

 

 

S4 Dip Switch Setting

Pump-Out

"E" Control Board

"G" Control Board

No. 5

No. 6

Frequency

 

 

 

 

 

 

 

OFF

OFF

Every cycle

After 1st freeze cycle

After 2nd freeze cycle

 

 

 

 

 

ON

OFF

Every 2 cycles

 

After 3rd freeze cycle

 

 

 

 

 

OFF

ON

Every 5 cycles

 

After 6th freeze cycle

ON

ON

Every 10 cycles

 

After 11th freeze cycle

 

 

 

 

 

Diagnosis: If PM does not reverse, check to see if S4 and S5 dip switch settings are in the factory default position. Check PM circuit and capacitor, check #5 pin (DBu wire) on CB K1 ten-pin connector for voltage. If water does not pump out, check and clean the check valve assembly and tubing.

52

Page 51 Page 53
Image 52
Page 51 Page 53
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
Top Page Image Contents