Hoshizaki KM-81BAJ Service Manual
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Hoshizaki KM-81BAJ Service Manual

Self-contained crescent cuber
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See also: Instruction Manual
Service Manual
Self-Contained Crescent Cuber
Models
KM-81BAJ
KM-116BAJ
KM-161BAJ, BWJ
hoshizakiamerica.com
Number: 73240
Issued: 8-20-2019

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Summary of Contents for Hoshizaki KM-81BAJ

  • Page 1 Service Manual Self-Contained Crescent Cuber Models KM-81BAJ KM-116BAJ KM-161BAJ, BWJ Number: 73240 hoshizakiamerica.com Issued: 8-20-2019...
  • Page 2 Hoshizaki provides this manual primarily to assist qualified service technicians in the service of the appliance. Should the reader have any questions or concerns which have not been satisfactorily addressed, please call, send an e-mail message, or write to the Hoshizaki Technical Support Department for assistance. Phone: 1-800-233-1940; (770) 487-2331 Fax: 1-800-843-1056;...

  • Page 3: Table Of Contents

    1. Air-Cooled Models (BAJ) ..................7 2. Water-Cooled Models (BWJ) ................... 8 3. Icemaking Compartment ..................9 B. Water/Refrigeration Circuit Diagram ................10 1. KM-81BAJ, KM-116BAJ ..................10 2. KM-161BAJ ......................11 3. KM-161BWJ ......................12 II. Sequence of Operation and Service Diagnosis ............... 13 A.
  • Page 4 VI. Preparing the Appliance for Periods of Non-Use ............48 VII. Disposal ......................... 50 VIII. Technical Information ....................51 A. Specification and Performance Data Sheets ............... 51 1. KM-81BAJ ......................51 2. KM-116BAJ ......................52 3. KM-161BAJ ......................53 4. KM-161BWJ ......................54...

  • Page 5: Important Safety Information

    Important Safety Information Throughout this manual, notices appear to bring your attention to situations which could result in death, serious injury, damage to the appliance, or damage to property. WARNING Indicates a hazardous situation which could result in death or serious injury.
  • Page 6 WARNING, continued • Do not make any alterations to the appliance. Alterations could result in electric shock, injury, fire, or damage to the appliance. • The appliance is not intended for use by persons (including children) with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.

  • Page 7: Construction And Water/Refrigeration Circuit Diagram

    I. Construction and Water/Refrigeration Circuit Diagram A. Construction 1. Air-Cooled Models (BAJ) Top Panel Spray Tube Separator Evaporator Door Water Supply Front Tube Panel Water Tank Louver Control Box Control Switch Hot Gas Valve Condenser Air Filter Compressor Front View Fan Motor Thermistor Cleaning...

  • Page 8: Water-Cooled Models (Bwj)

    2. Water-Cooled Models (BWJ) Spray Tube Evaporator Top Panel Separator Water Supply Tube Door Water Tank Front Panel Louver Control Switch Control Box Fan Motor Compressor Front View Condenser Air Filter Cleaning Valve Thermistor Inlet Water Valve Water Thermostatic Pump Expansion Rear Panel Valve...

  • Page 9: Icemaking Compartment

    3. Icemaking Compartment Inlet Water Valve Cleaning Valve Spray Tube Water Supply Pipe Evaporator Water Pump Separator Cube Guide Float Switch Water Tank...

  • Page 10: Water/Refrigeration Circuit Diagram

    B. Water/Refrigeration Circuit Diagram 1. KM-81BAJ, KM-116BAJ Water Supply Capillary Tube Accumulator Inlet Water Valve Spray Tube Cleaning Valve Thermistor Pump Motor Evaporator Water Tank Drain Valve Float Switch Drain Outlet Heat Exchanger Suction Line Hot Gas Drier Valve Condenser...

  • Page 11: Km-161Baj

    2. KM-161BAJ Water Supply Thermostatic Expansion Valve Inlet Water Valve Cleaning Valve Spray Tube Thermistor Evaporator Water Tank Drain Valve Pump Motor Float Switch Drain Outlet Heat Exchanger Hot Gas Valve Compressor Suction Line Strainer Discharge Line High Pressure Switch Drier Condenser Water Circuit...

  • Page 12: Km-161Bwj

    3. KM-161BWJ Water Supply Thermostatic Expansion Valve Inlet Water Valve Cleaning Valve Spray Tube Thermistor Evaporator Water Tank Drain Valve Pump Motor Float Switch Drain Outlet Heat Exchanger Hot Gas Valve Compressor Suction Line Strainer Discharge Line Drier High Pressure Switch Water Circuit Condenser...

  • Page 13: Sequence Of Operation And Service Diagnosis

    II. Sequence of Operation and Service Diagnosis A. Sequence of Operation Flow Chart 1. Operation Flow Chart...

  • Page 14: Shutdown Flow Chart

    2. Shutdown Flow Chart...

  • Page 15: Service Diagnosis

    B. Service Diagnosis WARNING • The appliance should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. • Risk of electric shock. Control switch in "OFF" position does not de-energize all loads Use extreme caution and exercise safe electrical practices.
  • Page 16 1. Sequence and Component Diagnosis 3) Power On: Plug the appliance into the electrical outlet. Move the control switch to the "ICE" position. A 5-sec. delay occurs. CB red "POWER OK" LED turns on. Note: • CB red "POWER OK" LED remains on unless the 10.5VAC power supply is interrupted (K2 connector).
  • Page 17 5a) Initial Harvest Cycle – LEDs 5, 6, and 8 are on. WV continues. Comp and HGV energize. CB monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to the harvest timer (S1 dip switch 1 &...
  • Page 18 6) Freeze Cycle – LED 5 and 7 is on. Comp and PM continue. FM energizes. HGV de-energizes. Appliance is held in freeze by a temperature/time short cycle protection cycle. Thermistor reaches 36°F (2°C), then the 5-min. short cycle protection timer starts. After the 5-min.
  • Page 19 g) WRV (KM-161B_J) Diagnosis: WRV is factory set and generally no adjustment is required. If WRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A. Specification and Performance Data Sheets." If refrigerant pressures are correct and WRV does not open, adjust or replace as needed. See "IV.C. Water Regulating Valve Adjustment (water-cooled models)."...
  • Page 20 Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above), after thermistor reaches 36°F (2°C) and the 5 min. short cycle protection timer has terminated, disconnect the FS connector. Check that CB LEDs 4, 5, 6, and 7 are on, PM stops, then restarts, DV energizes, and water is flowing down the drain through DV.

  • Page 21: Control Board Check

    C. Control Board Check Before replacing CB that does not show a visible defect and that you suspect is bad, always conduct the following check procedure. This procedure will help you verify your diagnosis. Alarm Reset: If CB is in alarm (beeping), press the "ALARM RESET" button on CB while CB is beeping.

  • Page 22: Bin Control Check

    D. Bin Control Check 1. Bin Control Check This appliance uses a mechanical bin control to control the ice level in the storage bin. No adjustment is required. To check BC, follow the steps below. 1) Remove the louver, move the control switch to the "OFF" position, then unplug the icemaker from the electrical outlet.
  • Page 23 2. Bin Control Cleaning Scale may build up on BC. Scale can cause the actuator paddle and magnet to stick. In this case, BC should be cleaned. WARNING CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews are securely in place after the icemaker is serviced. Make sure that none have fallen into the dispense unit/ice storage bin.
  • Page 24 5) Remove the actuator paddle from the switch mount. 6) Wipe down the switch mount and actuator paddle with 1 part of Hoshizaki "Scale Away" and 25 Parts warm water. Rinse the switch mount and actuator paddle thoroughly with clean water. See Fig. 3.

  • Page 25: Float Switch Check And Cleaning

    E. Float Switch Check and Cleaning FS is used to determine that there is sufficient water in the water tank after the 1-min. fill cycle and after each harvest cycle. FS 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.
  • Page 26 See Fig. 7. 7) Wipe down FS housing, shaft, float, and retainer clip with a mixture of 1 part Hoshizaki "Scale Away" and 25 parts warm water. Rinse the parts thoroughly with clean water.

  • Page 27: Thermistor Check

    F. Thermistor Check To check thermistor resistance, follow the steps below. 1) Unplug the icemaker from the electrical outlet. 2) Remove the louver, then move the control switch to the "OFF" position. 3) Remove the top panel. 4) Remove the thermistor from the refrigerant tubing. 5) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 min.

  • Page 28: Diagnostic Tables

    H. Diagnostic Tables 1. No Ice Production No Ice Production - Possible Cause 1. Power Supply a) Off, blown fuse, or tripped breaker. b) Unplugged or loose connection. c) Not within specifications. 2. Fuse (Control Box) a) Blown. 3. Control Switch a) In "OFF"...
  • Page 29 2. Freeze-Up Defrost and clean the icemaker prior to diagnosing freeze-up. Fill out a freeze-up checklist. See "II.I. Freeze Up Check List," the Hoshizaki America Technician's Pocket Guide, or contact your local distributor for a copy of the freeze-up checklist.
  • Page 30 Freeze-Up - Possible Cause Freeze Cycle 1. Evaporator a) Scaled up. b) Damaged. 2. Spray Tubes and/or Spray a) Dirty. Guides b) Out of position. 3. Refrigerant Charge a) Low. 4. Control Board a) Freeze timer (S1 dip switch 9 & 10) set incorrectly. See "II.C.
  • Page 31 Low Ice Production - Possible Cause Long Freeze Cycle 1. Evaporator a) Scaled up, dirty. 2. Float Switch a) Scaled up, dirty. See "II.E. Float Switch Check b) Float sticking. and Cleaning" c) Defective switch. 3. Inlet Water Valve a) Leaking by. 4.

  • Page 32: Freeze-Up Check List

    I. Freeze-Up Check List Freeze-Up Check List Please Complete When Diagnosing a Freeze-Up, Refrigerant Leak, or Low Charge Technical Support Fax #: 770-487-3360 Make Copies And Use As Needed Model #___________________________ Serial # _________________________Install Date______________Fail Date___________ List model and manufacture of bin or dispenser__________________________. Date appliance was last cleaned:__________.

  • Page 33: Controls And Adjustments

    III. Controls and Adjustments • A Hoshizaki exclusive control board is employed in KM series appliances. • All models are pretested and factory adjusted. • For a control board check procedure, see "II.C. Control Board Check." NOTICE • Fragile, handle very carefully.

  • Page 34: Control Board Layout

    A. Control Board Layout Control Board • Relay LEDs (6) (indicate which relays are energized as • K7 Connector listed below) Transformer • LED 5 (X1 Relay) Compressor (Comp) Fan Motor-Remote (FMR) • LED 6 (X2 Relay) • K3 Connector Hot Gas Valve (HGV) Fan Motor (FM) Power Relay...

  • Page 35: Led Lights And Audible Alarm Safeties

    B. LED Lights and Audible Alarm Safeties Beep occurs and red CB "POWER OK" LED turns on when control switch is moved to "ICE" position. Sequence Green LEDs 4 through 8 turn on and sequence from initial startup as listed in the table below.

  • Page 36: Settings And Adjustments

    NOTICE Dip switches are factory set. Failure to maintain factory settings may adversely affect performance and warranty coverage. For more information, contact your Hoshizaki Service Center. 1. Default Dip Switch Settings The dip switches are factory-adjusted to the following positions: S1 Dip Switch No.

  • Page 37: Harvest Time (S1 Dip Switch 1 & 2)

    2. Harvest Time (S1 dip switch 1 & 2) The harvest timer starts counting when the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads 3.9 kΩ from the thermistor. The harvest timer is factory set, and generally no adjustment is required. However, a setting longer than the factory setting may be advised in cases where the drain provided at harvest needs to be prolonged for extra cleaning.

  • Page 38: Pump-Out Frequency Control (S1 Dip Switch 5 & 6)

    4. Pump-Out Frequency Control (S1 dip switch 5 & 6) The pump-out frequency control is factory set to drain the water tank every 10 cycles. 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 can be set to have a pump-out occur every cycle, or every 10 cycles.

  • Page 39: Freeze Timer (S1 Dip Switch 9 & 10)

    In this case, see "II.H.3. Low Ice Production" for possible solutions. The freeze timer is factory set and no adjustment is required. Before changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for recommendations.

  • Page 40: Minimum Harvest Time (S2 Dip Switch 3)

    Do not adjust. This must be left in the factory default position or the unit will not operate properly. The KM-81BAJ, KM-116BAJ, and KM-161BAJ/BWJ do not refill. 10. Harvest Completion Detection Control (S2 dip switch 4) NOTICE Factory set for proper operation.

  • Page 41: Overfreeze Detection Control (S2 Dip Switch 5)

    Do not adjust. This must be left in the factory default position or the unit will not operate properly. It is deactivated on the KM-81BAJ, KM-116BAJ, and KM-161BAJ/BWJ. When activated, the thermistor detects the temperature of the evaporator outlet to find overfreeze in a harvest cycle and at the beginning of a freeze cycle.

  • Page 42: Slush Control (S2 Dip Switch 6)

    12. Slush Control (S2 dip switch 6) NOTICE Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance. This dip switch setting provides slush control during the freeze cycle. Disabled (OFF): When the evaporator temperature reaches 41°F (5°C) the control board reads a 4.8 kΩ...

  • Page 43: Refrigeration Circuit And Component Service Information

    IV. Refrigeration Circuit and Component Service Information WARNING • This appliance should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. • Move the control switch to the "OFF" position and turn off the power supply. Place the disconnect in the "OFF"...
  • Page 44 2. Brazing WARNING • R-404A itself is not flammable at atmospheric pressure and temperatures up to 176°F (80°C). • R-404A itself is not explosive or poisonous. However, when exposed to high temperatures (open flames), R-404A can be decomposed to form hydrofluoric acid and carbonyl fluoride both of which are hazardous.
  • Page 45 Remember to loosen the connection and purge the air from the hose. For the required refrigerant charge, see the rating label inside the icemaker. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets ARI Standard 700 (latest edition) be used.

  • Page 46: Component Service Information

    • The thermistor should be at the 12 o'clock position on the tube. • Smoothly fill the recessed area of the thermistor holder with high thermal conductive type sealant. Hoshizaki America part number 4A0683-01 (Silicone Heat Sink Compound 10-8108 manufactured by GC Electronics), KE-4560 RTV (manufactured by ShinEtsu Silicones), or equivalent are recommended.

  • Page 47: Maintenance

    V. Maintenance The maintenance schedule below is a guideline. More frequent maintenance may be required depending on water quality, the appliance's environment, and local sanitation regulations WARNING • Only qualified service technicians should service the appliance. • To reduce the risk of electric shock, do not touch the control switch or plug with damp hands •...

  • Page 48: Preparing The Appliance For Periods Of Non-Use

    VI. Preparing the Appliance for Periods of Non-Use NOTICE • When storing the appliance for an extended time or in sub-freezing temperatures, follow the instructions below to prevent damage. • To prevent damage to the water pump, do not operate the appliance with the control switch in the "WASH"...
  • Page 49 3. On water-cooled model, remove the water from the water-cooled condenser: 1) Make sure the appliance is unplugged and the control switch is in the "OFF" position. 2) Remove the rear cover. 3) Close the condenser water supply line shut-off valve. If connected to a closed loop system, also close the condenser return line shut-off valve.

  • Page 50: Disposal

    VII. Disposal The appliance contains refrigerant and must be disposed of in accordance with applicable national, state, and local codes and regulations. Refrigerant must be recovered by properly certified service personnel.

  • Page 51: Technical Information

    We reserve the right to make changes in specifications and design without prior notice. A. Specification and Performance Data Sheets Pressure data is recorded at 5 min. into freezing cycle. The data not in bold should be used for reference only. 1. KM-81BAJ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 3.5 A (5 Min.

  • Page 52: Km-116Baj

    2. KM-116BAJ Specification Data AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 5.5 A (5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 340 (8.10) 330 (6.44) WATER gal./24HR (gal./100 lbs.) 20 (20.0)

  • Page 53: Km-161Baj

    3. KM-161BAJ Specification Data AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 7.1 A (5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 440 (8.60) 440 (6.47) WATER gal./24HR (gal./100 lbs.) 28 (23.0)

  • Page 54: Km-161Bwj

    4. KM-161BWJ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 6.4 A (5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 330 (6.23) 360 (5.61) WATER gal./24HR (gal./100 lbs.) 31 (24.2)

  • Page 55: Wiring Diagram

    B. Wiring Diagram 1. KM-81BAJ, KM-116BAJ, KM-161BAJ, KM-161BWJ...

This manual is also suitable for:

Km-116bajKm-161bwjKm-161baj

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