Service Manual Modular Crescent Cuber with Model KMD-460MAJ, MWJ KMD-530MAJ, MWJ, MRJ 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 and may result in costly water damage.
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.
IV. Refrigeration Circuit and Component Service Information.............................................. 44 A. Refrigeration Circuit Service Information..................................................................... 44 B. Component Service Information................................................................................... 47 C. Water Regulating Valve Adjustment (water-cooled model)........................................... 47 V. Maintenance.................................................
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 • Children should be properly supervised around this appliance. • Do not climb, stand, or hang on the appliance or allow children or animals to do so. Serious injury could occur or the appliance could be damaged. • Do not use combustible spray or place volatile or flammable substances near the appliance. They might catch fire. • Keep the area around the appliance clean. Dirt, dust, or insects in the appliance could cause harm to individuals or damage to the appliance.
I. Construction and Water/Refrigeration Circuit Diagram A. Construction 1.
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B. Water/Refrigeration Circuit Diagram 1.
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Startup Cycle Steps 13 Legend: BC–bin control CB–control board Comp–compressor FM–fan motor FMR–fan motor-remote FS–float switch HGV–hot gas valve HPT–harvest pump time LLV–liquid line valve PM–pump motor WV–inlet water valve FS check Comp energized FM energized FMR energized LLV energized PM energized HGV de-energized FS closed 5-min. minimum freeze timer in control Slush Control Thermistor temperature reaches 36°F (2.2°C) (5.8 kΩ). PM de-energized for 10 sec.
BC Operation Shutdown and Restart 14 Legend: BC–bin control BC open (BC actuator paddle engaged) Green "BC CLOSED" LED off Yellow "BC OPEN" LED on 2. Icemaker Off All components de-energized. Yellow "BC OPEN" LED continues. All components de‑energized. 1. Bin Full Shutdown Delay: • Fill Cycle–15 sec. after activation. • Harvest Cycle–At the end of the harvest cycle, or up to 15 sec. into the freeze cycle if activated at the end of the harvest cycle. • Freeze Cycle– 15 sec.
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.
1. Diagnosis 3) Power On: Turn on the power supply, then move the control switch to the "ICE" position. A 5‑sec. delay occurs. CB red "POWER OK" LED and green "BC CLOSED" LED turn on. If yellow "BC OPEN" LED is on (indicating a full bin), check BC. Move ice away from BC actuator paddle. If yellow "BC OPEN" LED stays on, see "II.D. Bin Control Check.". Note: • CB red "POWER OK" LED remains on unless the 10.5VAC power supply is interrupted (K2 connector). • Check CB using the steps in "II.C.
5a) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV and X11 relay continue. Comp, HGV, X10, X12, and X14 relays 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 (S4 dip switch 1 & 2). The harvest timer has settings of 60, 90, 120, and 180 sec.
5b) Harvest Pump Time (Harvest Assist) – LEDs 1, 3, and 2 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 (S4 dip switch 1 & 2 and S5 dip switch 4). When WV de-energizes, LED 4 turns off, X11 relay de-energizes and LED 3 turns on. PM energizes. Comp, HGV, X10, X12, and X14 relays continue. a) Thermistor Diagnosis: Place a thermometer on the suction line next to the thermistor.
6) Freeze Cycle – LED 1 is on. Comp, PM, and X14 relay continue. FMR, FM, and LLV energize. HGV, X10, and X12 relays de‑energize. Appliance is held in freeze by a 5-min. short cycle protection timer. After 5-min. short cycle protection timer terminates and FS opens, freeze cycle terminates. Note: PM power supply switches from CB K1 #5 (DBU) in harvest to K1 #4 (R) in freeze. Slush Control: When slush control is enabled (S5 dip switch 5 "ON"), PM de-energizes when thermistor reaches 36°F (2.2°C) (5.
e) FM and LLV Diagnosis: If FM or LLV does not energize, check for 115VAC at CB K1 #3 (BK) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present: For FM, check capacitor, motor winding, and blade for binding. For LLV, check coil voltage and continuity. f) Refrigerant Pressures, HM, and TXV Diagnosis: If evaporator is still not cooling, check refrigerant pressures. See "VIII.A. Specification and Performance Data Sheets." Next, check HM operation.
7) Pump-Out Cycle – LEDs 1, 3, and 2 are on (10/20 second pump-out). Timing of the first pump-out is determined by S4 dip switch 5. See the table below. Control Board Settings S4 Dip Switch Setting No. 5 Pump-Out Frequency 1st Pump-Out OFF Every 10 cycles After 11th freeze cycle ON Every cycle After 2nd freeze cycle Comp and X14 relay continue, HGV energizes, FM, FMR, and LLV de-energize. NOTICE! S4 dip switch 3 & 4 must not be set to 3 off and 4 on.
e) X13 Relay Diagnosis - If 115VAC is present at X12 terminal #3 (DBU) to neutral and PM and DV are not energized, check for 115VAC at X13 terminal #8 (DBU) to neutral (W). If 115VAC is present and X13 relay is de-energized, replace X13 relay. (1) For PM and X13 Relay: If 115VAC is present at X13 terminal #8 (DBU), check for 115VAC at X13 relay #6 (BK) and X13 relay #4 (Y) to neutral (W). If 115VAC is present at X13 relay #6 (BK) and not at X13 relay #4 (Y), replace X13 relay (contacts sticking open).
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) Turn off the power supply. 2) Remove the front panel, then move the control switch to the "OFF" position. 3) Remove the control box cover. 4) Remove the base cover and clear any ice away from BC. BC Connector 5) Disconnect BC connector from CB K4 connector.
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 dispenser unit/storage bin. 1) Turn off the power supply. 2) Remove the front panel, then move the control switch to the "OFF" position.
E. Float Switch Check and Cleaning F/S is used to determine that there is sufficient water in the water tank after the 1‑minute fill cycle and after each harvest cycle. F/S 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. Note: F/S is not part of refill operation. 1. Float Switch Check To check F/S, follow the steps below. 1) Turn off the power supply. 2) Remove the front panel.
21) Move the control switch to the "ICE" position. 22) Replace the front panel in its correct position. 23) Turn on the power supply to start the automatic icemaking process. Legend: CB–control board; F/S–float switch 2. Float Switch Cleaning Depending on local water conditions, scale may build up on F/S. Scale can cause F/S to stick. In this case, F/S should be cleaned. 1) Turn off the power supply. 2) Remove the front panel. 3) Place the control switch in the "SERVICE" position.
F. Thermistor Check To check thermistor resistance, follow the steps below. 1) Turn off the power supply. 2) Remove the front panel, then move the control switch to the "OFF" position. 3) Remove the top and right side panels, then remove the control box cover. 4) Remove the thermistor. 5) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes. 6) Disconnect the thermistor connector from CB K3 (white) connector and check resistance between thermistor leads.
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. WARNING! Moving control switch to "OFF" position does not de-energize all components. 2.
H. Diagnostic Tables 1. No Ice Production No Ice Production - Possible Cause 1. Power Supply a) Off, blown fuse, or tripped breaker. b) Not within specifications. 2. Main Transformer a) Voltage tap switch not set to proper voltage. b) Coil winding open or shorted, defective. 3. Fuse (control box) a) Blown. 4. Control Switch a) In "OFF" or "WASH" position. b) Bad contacts. 5. High-Pressure Switch a) Dirty condenser. b) Fan motor not operating. c) Refrigerant overcharged. d) Bad contacts.
No Ice Production - Possible Cause 16. Thermostatic Expansion Valve a) Bulb loose. b) Operating erratically. 17. Liquid Line Valve a) Closed in freeze cycle. b) Open in harvest cycle. 18. Fan Motor a) Motor winding open. b) Bearing worn out or locked rotor. c) Defective capacitor. 19. 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 (S4 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.
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__________Freeze-Up Date___________ List model and manufacture of bin or dispenser__________________________. Date appliance was last cleaned:__________.
III. Controls and Adjustments • A Hoshizaki exclusive control board is employed in KMD 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 "J" Control Board • Bin Control Switch Closed LED (green) • "ALARM RESET" Button • S4 Dip Switch • K3 (white) Connector Thermistor (harvest control and high temperature safety) • Bin Control Switch Open LED (yellow) • Alarm Buzzer • K4 (red) Connector Bin Control • S5 Dip Switch • Ext. Harvest LED (yellow) (lights when water line thermistor initiates extended harvest) Not used this model. • POWER OK LED (red) (lights when 10.
B. LED Lights and Audible Alarm Safeties Beep occurs and red "POWER OK" LED turns on when control switch is moved to "ICE" position. Sequence Green LEDs 1 through 4 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 1, 4, 3, 2. Sequence Step LED Energized Components 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.
2. Harvest Time (S4 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 (S4 dip switch 5) 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 S4 dip switch 5. See the table below.
6. Harvest Pump Time (Harvest Assist) (S4 dip switch 7) NOTICE Factory set for proper operation. Do not adjust. Adjustment outside of the factory default setting may result in damage to the appliance. a) Harvest Pump Time (Harvest Assist) Depending on S4 dip switch 7 setting, the pump motor either stays off or is energized during the last seconds of the harvest cycle. When the pump motor is energized (S4 dip switch 7 on), water circulates over the evaporator.
8. Freeze Timer (S4 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.
11. Minimum Harvest Time (S5 dip switch 4) NOTICE Factory set for proper operation. Do not adjust. Adjustment outside the factory default setting may result in damage to the appliance. S5 Dip Switch Setting No. 4 Minimum Harvest Timer OFF 120 sec. ON 70 sec. 12. Slush Control (S5 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.
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 AHRI 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. 3 phase: Install a new magnetic contactor. 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.
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 turn off the power supply.
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. • The pump motor is energized continuously when the control switch is in the "SERVICE" position. 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.
3. On water-cooled model, remove the water from the water-cooled condenser: 1) Make sure the power supply is off, then remove the front panel and right side panel. 2) 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. 3) Open the condenser water supply line drain valve. If connected to a closed loop system, also open the condenser return line drain valve.
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. KMD-460MAJ 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. KMD-460MWJ 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 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.
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Cut-out Cut-in * High-Pressure Switch Air-Cooled and Water-Cooled Model Remote Air-Cooled Models 412±21.3 384±21.3 0 PSIG 0 PSIG 327±21.3 PSIG 284±21.3 PSIG * B. Wiring Diagram 1.
