Service Manual Self-Contained Crescent Cuber Models KM-231BAJ KM-301BAJ, BWJ hoshizakiamerica.
WARNING Only qualified service technicians should install and service the appliance. To obtain the name and phone number of your local Hoshizaki Certified Service Representative, visit www.hoshizaki.com. No service should be undertaken until the technician has thoroughly read this Service Manual. Failure to service and maintain the appliance in accordance with this manual will adversely affect safety, performance, component life, and warranty coverage.
IMPORTANT This manual should be read carefully before the appliance is serviced. Read the warnings and guidelines contained in this manual carefully as they provide essential information for the continued safe use, service, and maintenance of the appliance. Retain this manual for any further reference that may be necessary. CONTENTS Important Safety Information.................................................................................................. 5 I.
V. Maintenance..................................................................................................................... 46 VI. Preparing the Appliance for Periods of Non-Use............................................................. 47 VII. Disposal.......................................................................................................................... 49 VIII. Technical 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. NOTICE Indicates a situation which could result in damage to the appliance or property. IMPORTANT Indicates important information about the use and care of the appliance.
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. • Children should be properly supervised around this appliance.
I. Construction and Water/Refrigeration Circuit Diagram A. Construction 1.
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Cube Guide Evaporator Spray Tube 10 Pump Motor Water Tank Water Circuit Refrigerant Circuit Float Switch Water Valve Drain Thermistor Drain Valve Cleaning Valve Water Supply Expansion Valve Suction Line Discharge Line Compressor Drier Access Valve Insulation Tube Fan Condenser Hot Gas Valve Strainer High Pressure Switch B. Water/Refrigeration Circuit Diagram 1.
Cube Guide Evaporator Spray Tube 11 Pump Motor Float Switch Water Circuit Refrigerant Circuit Water Tank Water Valve Drain Thermistor Drain Valve Cleaning Valve Water Supply Water Supply Expansion Valve Suction Line Hot Gas Valve Strainer High Pressure Switch Discharge Line Compressor Drier Drain Access Valve Insulation Tube Water Condenser Water Regulating Valve 2.
Comp energized HGV energized WV energized FS closed Thermistor in control FS check 5-min. min. freeze timer FS opens or Comp energized freeze timer HGV energized terminates DV energized PM de-energizes for 2 sec., then restarts for 10/20 sec. FM de-energized FS in control • Factory set for every 10th cycle (S1 dip switch 5 & 6) • Pump motor stops for 2 sec., then restarts for 10/20 sec. (S1 dip switch 3 & 4) 4.
BC Operation 13 Legend: BC–bin control DV–drain valve FS–float switch PM–pump motor 2 sec. after all components de-energize, DV and PM energize for a max. of 5 min. or until the FS opens. 2. Water Tank Drain To 1. 1-Minute Fill Cycle Icemaker starts at "1. 1-Minute Fill Cycle." 4. Ice Level Lowered BC closed (BC actuator paddle disengaged) Red "POWER OK" LED on solid Minimum off time: 90-sec. minimum 90-sec. off timer terminates before the appliance can restart. 3.
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. • Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
b) HPS Diagnosis: Check that the condenser coil is not clogged or restricted. Let refrigeration circuit pressures equalize. If HPS does not reset and pressures are equalized, replace HPS. If pressures are not equalized, reclaim refrigerant and diagnose refrigeration circuit restriction. Check that there are no restrictions in the refrigeration circuit. Harvest Cycle: HGV, strainer, or check valve. Freeze Cycle: FM, TXV, WRV, strainer, and drier.
c) WRV Diagnosis: Confirm WRV is not leaking by. If WRV is leaking by, confirm HGV is open. Next, check for proper refrigerant pressures. If refrigerant pressures are correct, adjust or replace WRV. See "IV.C. Water Regulating Valve Adjustment (water‑cooled models)." 5b) Harvest Pump Time (Harvest Assist) – LEDs 5, 6, and 7 are on. 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 & 2 and S2 dip switch 4).
Slush Control: When slush control is enabled (S2 dip switch 5 "ON"), PM de-energizes when thermistor reaches 50°F (10°C) (3.9kΩ) for 10 sec. then, energizes for 50 sec. repeatedly. When thermistor reaches 34°F (1°C) (5.9kΩ) PM de-energizes for 10 sec., energizes for 50 sec., de-energizes for 10 sec., again, then energizes the remainder of the freeze cycle. a) Freeze Cycle Diagnosis: Confirm Comp and PM continue. Confirm that FM energizes. Confirm WRV opens. Next, confirm HGV de-energizes.
g) WRV 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)." h) Freeze Termination Diagnosis: After thermistor has reached 36°F (2°C) and the 5 min.
Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above), after 5 min. of freeze disconnect 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. If not, continue to steps below. a) CB Diagnosis: Confirm FM de-energizes. If FM is energized with LEDs 4, 5, 6, and 7 on, replace CB. If PM does not stop and restart and DV does not energize, check that CB LEDs 4, 5, 6, and 7 are on. If not, replace CB.
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. WARNING! Risk of electric shock. Care should be taken not to touch live terminals. Once reset, the icemaker starts at the 1-minute fill cycle. For audible alarm information, see "III.B.
D. Bin Control Check 1. Bin Control Check This appliance uses a lever-actuated proximity switch to control the ice level in the storage bin. No adjustment is required. To check BC, follow the steps below. 1) Remove the louver, then move the control switch to the "OFF" position. Move the service switch to the "DRAIN" position, then move the control switch to the "SERVICE" position. Allow the water tank to drain completely.
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. 1) Remove the louver, then move the control switch to the "OFF" position.
7) Remove the actuator paddle from the switch mount. 8) 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. 9) Replace the actuator paddle back on the switch mount. Replace the proximity switch. 10) Replace and secure the bin control assembly back in its correct position. 11) Replace and secure the water tank back in its correct position.
11) Check for continuity across FS leads (2 black (BK) wires). With the water tank full, FS should be closed. If FS is closed and the icemaker will not switch from the 1-min. fill cycle to the initial harvest cycle, replace CB. If FS is open, confirm that the water tank is full. If the water tank is not full, check the water supply, water filters, and inlet water valve. If the water tank is full, follow the steps in "II.F.2. Float Switch Cleaning." After cleaning FS, check it again. Replace if necessary.
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. 6) From the compressor area, locate the thermistor/CB connector protective plastic bundle.
G. Switches Two control switches are used to control operation. These switches are referred to as the "control switch" and the "service switch" and are located on the control box. 1. Control Switch The control switch has three positions: "OFF" for power off, "ICE" for icemaking, and "SERVICE" to activate the service switch. 2. Service Switch When the control switch is in the "SERVICE" position, the control switch supplies power to the service switch and the machine is in service mode.
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. b) Not within specifications. 2. Fuse (Control Box) a) Blown. 3. Control Switch a) In "OFF" or "SERVICE" position. b) Bad contacts. 4. High-Pressure Switch a) Dirty condenser. b) Fan motor not operating. c) Refrigerant overcharged. d) Bad contacts. e) Refrigerant lines or components plugged. f) HGV defective. 5.
No Ice Production - Possible Cause 15. Thermostatic Expansion Valve a) Bulb loose. b) Operating erratically. 16. Fan Motor a) Motor winding open. b) Bearing worn out or locked rotor. c) Defective capacitor. 17. Water System a) Water leaks causing short freeze time. 2. Freeze-Up Defrost and clean the icemaker prior to diagnosing freeze-up. Fill out a freeze-up checklist. See "II.I.
Freeze-Up - Possible Cause Freeze Cycle 1. Evaporator a) Scaled up. b) Damaged. 2. Spray Tubes and/or Spray Guides a) Dirty. 3. Refrigerant Charge a) Low. 4. Control Board See "II.C. Control Board Check" a) Freeze timer (S1 dip switch 9 & 10) set incorrectly. 5. Inlet Water Valve a) Leaking by. 6. Float Switch See "II.E. Float Switch Check and Cleaning" a) Float does not move freely. 7. Pump Motor a) RPM too slow. b) Out of position. b) Defective. b) Defective. b) Impeller damaged. 8.
Low Ice Production - Possible Cause Long Freeze Cycle 1. Evaporator a) Scaled up, dirty. 2. Float Switch See "II.E. Float Switch Check and Cleaning" a) Scaled up, dirty. 3. Inlet Water Valve a) Leaking by. 4. Hot Gas Valve a) Erratic or open. 5. Condenser a) Clogged. 6. Control Board See "II.C. Control Board Check" a) Float switch connection loose (K5). 7. Refrigerant Charge a) Low. 8. Thermostatic Expansion Valve a) Bulb loose. b) Float sticking. c) Defective switch. b) Defective.
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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. • The control board contains integrated circuits, which are susceptible to failure due to static discharge. It is especially important to touch the metal part of the icemaker when handling or replacing the control board.
A. Control Board Layout 1. "H" Control Board "H" Control Board • Relay LEDs (6) (indicate which relays are energized as listed below) • K7 Connector Transformer • LED 5 (X1 Relay) Compressor (Comp) Fan Motor-Remote (FMR) • LED 6 (X2 Relay) Hot Gas Valve (HGV) Fan Motor (FM) (FM off when LED on) • K3 Connector Power Relay • "POWER OK" LED (Lights when power is supplied to the board. Flashes when bin control is activated.
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. Order of green LEDs from the outer edge of control board is 5, 6, 8, 9, 4, and 7. Sequence Step 1-Minute Fill Cycle Harvest Cycle LED 8 5, 6, 8 Energized Components WV Comp, FM, HGV, WV Time LEDs are On Min. Max.
C. 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.
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.
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. The first pump-out is dependent on S1 dip switch 5 & 6. See the table below.
6. Freeze Timer (S1 dip switch 9 & 10) NOTICE Adjust to proper specification, or the icemaker may not operate correctly. The freeze timer setting determines the maximum allowed freeze time to prevent possible freeze-up issues. Upon termination of the freeze timer, the control board initiates the harvest cycle or pump-out cycle. After 2 consecutive freeze timer terminations, the control board shuts down the icemaker. In this case, see "II.H.3. Low Ice Production" for possible solutions.
9. Minimum Harvest Time (S2 dip switch 3) NOTICE Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance. Do not adjust. This must be left in the factory default position or the unit will not operate properly. The KM-231BAJ and KM-301BAJ/BWJ do not refill. 10. Harvest Completion Detection Control (S2 dip switch 4) NOTICE Factory set for proper operation. Do not adjust.
11. Overfreeze Detection Control (S2 dip switch 5) NOTICE Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance. 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-231BAJ and KM-301BAJ/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.
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 signal from the thermistor and de-energizes the water pump for 10 sec., then energizes the water pump for the duration of freeze time.
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" position. Lockout/Tagout to prevent the power supply from being turned back on inadvertently.
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. • Do not use silver alloy or copper alloy containing arsenic. 1) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
4) Close the low-side valve and high-side valve on the gauge manifold. 5) Disconnect the gauge manifold hose from the vacuum pump and attach it to a refrigerant service cylinder. 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.
B. Component Service Information NOTICE When replacing a component listed below, see the notes to help ensure proper operation. Component Compressor Notes 1 phase: Install a new start capacitor, run capacitor, and start relay. Thermostatic • Attach the thermostatic expansion valve bulb to the suction line in the same location as Expansion Valves the previous bulb. • The bulb should be between the 10 and 2 o'clock positions on the tube. • Secure the bulb with the clamp and holder, then insulate it.
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 service switch with damp hands • Before servicing: Move the control switch to the "OFF" position and unplug the power supply cord from the electrical outlet.
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 "SERVICE" position when the water tank is empty. When the appliance is not used for two or three days under normal conditions, it is sufficient to move the control switch to the "OFF" position.
5) Open the water regulating valve by using a screwdriver to pry up on the spring retainer underneath the spring. While holding the valve open, blow out the condenser using the compressed air or carbon dioxide supply until water stops coming out. 6) Close the drain valve(s). 7) Replace the right side panel and front panel in their correct positions.
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.
VIII. 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-231BAJ Specification Sheet AC SUPPLY VOLTAGE AMPERAGE MINIMUM CIRCUIT AMPACITY MAXIMUM FUSE SIZE ELECTRIC & WATER CONSUMPTION ELECTRIC W (kWH/100 lbs.) WATER gal./24HR (gal./100 lbs.
2. KM-301BAJ Specification Sheet AC SUPPLY VOLTAGE AMPERAGE MINIMUM CIRCUIT AMPACITY MAXIMUM FUSE SIZE ELECTRIC & WATER CONSUMPTION ELECTRIC W (kWH/100 lbs.) WATER gal./24HR (gal./100 lbs.) ICE PRODUCTION PER CYCLE APPROXIMATE STORAGE CAPACITY BIN CONTROL SYSTEM REFRIGERANT CHARGE Performance Data Sheet APPROXIMATE ICE PRODUCTION PER 24 HR. lbs./day kg./day APPROXIMATE ELECTRIC CONSUMPTION watts APPROXIMATE WATER CONSUMPTION PER 24 HR. gal./day m3/day FREEZING CYCLE TIME min. HARVEST CYCLE TIME min.
3. KM-301BWJ Specification Sheet AC SUPPLY VOLTAGE AMPERAGE MINIMUM CIRCUIT AMPACITY MAXIMUM FUSE SIZE ELECTRIC & WATER CONSUMPTION ELECTRIC W (kWH/100 lbs.) WATER gal./24HR (gal./100 lbs.) WATER COOLED CONDENSER gal./24HR (gal./100 lbs.) ICE PRODUCTION PER CYCLE APPROXIMATE STORAGE CAPACITY BIN CONTROL SYSTEM REFRIGERANT CHARGE 115/60/1 5.7 A ( 5 Min. Freeze AT 104°F / WT 80°F) 15 A 15 A 90/70°F 70/50°F 480 (4.90) 490 (4.16) 47 (20.0) 54 (18.9) 218 (92) 105 (37) 4.9 lbs. (2.2 kg) 238pcs. 100 LBS.
KM-301BAJ Model KM-231BAJ and KM-301BWJ Models EXTERNAL PROTECTOR INTERNAL PROTECTOR 53 327±22 PSIG Cut-in 284±22 PSIG 384±22 0 PSIG 412± 0 PSIG 22 Cut-out * Water-Cooled Model 1. KM-231BAJ, KM-301BAJ, KM-301BWJ Air-Cooled Model * High-Pressure Switch B.
