Service Manual Self-Contained Cuber Models AM-50BAJ AM-50BAJ-DS AM-50BAJ-AD AM-50BAJ-ADDS 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.................................................................................................. 4 I.
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, serious injury, fire, or damage. • Do not use an extension cord. • Do not use an appliance with a damaged power cord. The power cord should not be altered, jerked, bundled, weighed down, pinched, or tangled. Such actions could result in electric shock or fire. To unplug the appliance, be sure to pull the plug, not the cord, and do not jerk the cord.
NOTICE • Protect the floor when moving the appliance to prevent damage to the floor. • When making water supply or drain line repairs, follow the requirements found in the instruction manual to reduce the risk of costly water damage. • In areas where water damage is a concern, confirm appliance is installed in a contained area with a floor drain. • Confirm the appliance is in a location that stays above freezing. Normal operating ambient temperature must be within 45°F to 100°F (7°C to 38°C).
I. Construction and Water/Refrigeration Circuit Diagram A.
B.
102-sec. WVT 50-sec. HT 1. Initial Harvest Cycle 9 BC open All components de‑energized except BCH and DP All components de-energized. BC closed No ice touching thermostatic bulb. Icemaker starts at "1. Initial Harvest Cycle." 3. Ice Level Lowered BCH continues Comp continues FM de-energized PM de-energized HGV energized WV energized 2. Icemaker Off 50-sec. HT in control Thermistor temperature reaches 45°F (7°C) (4.5 kΩ or less). 50 sec. HT starts. 102-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. Use extreme caution and exercise safe electrical practices. • Risk of electric shock. Control switch in "OFF" position does not de‑energize all loads (optional drain pump). • Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
1. Operation Diagnosis 3) Power On/Initial Harvest Cycle – LED 1 is flashing and LED 3 is on. Move the control switch to the "ICE" position. LEDs 1 (green), 3 (green), and 4 (orange) turn on briefly then turn off. Then LED 1 starts flashing, LED 3 turns on and Comp, HGV, and WV energize. Initial harvest cycle starts. 50-sec. HT and 102-sec. WVT start. Note: 24VAC to CB is confirmed with a flashing LED 1. a) Power On Diagnosis: Confirm green LED 1 is flashing.
4) Initial Freeze Cycle – LED 1 is flashing and LEDs 3 and 2 are on. Comp and 102-sec. WVT (WV continues another 52 sec. in freeze cycle) continue. FM and PM energize. HGV de‑energizes. When 102-sec. WVT terminates, LED 3 turns off and WV de-energizes. CB monitors the cooling of the evaporator via the thermistor located on the evaporator for freeze termination. When the thermistor drops to 27°F (-3°C), CB reads 6.8 kΩ from the thermistor and starts 3-min. FT.
b) HGV Diagnosis: If Comp is energized and evaporator is not warming, check that HGV energizes and opens. If not, check for 115VAC at CB C1 (BR) to neutral (W) and CB B1 (P) to neutral (W). If 115VAC is present at CB C1 (BR) to neutral (W) and not at CB B1 (P) to neutral (W), replace CB. If 115VAC is not present at CB C1 (BR) to neutral (W), check wiring connections from BC. If 115VAC is present, check HGV coil continuity. Replace as needed. c) WV Diagnosis: Confirm LED 3 is on. If not, replace CB.
7) Shutdown. When the appliance is running, hold ice in contact with the thermostatic bulb. BC switch opens within 10 sec., shutting down the appliance. BC is factory set, and generally no adjustment is required. However, adjustment may be needed in some conditions, particularly at higher altitude locations.
D. Thermistor Check To check thermistor resistance, follow the steps below. 1) Move the control switch to the "OFF" position. 2) Unplug the appliance. 3) Remove the control box cover. 4) Remove the thermistor from the evaporator. 5) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 min. 6) Disconnect the thermistor connector from CB and check the resistance between thermistor leads. Normal range is 5.5 to 6.5 kΩ. If outside the normal range, replace the thermistor.
E. Diagnostic Tables 1. No Ice Production No Ice Production - Possible Cause 1. Power Supply a) Unplugged, off, blown fuse, or tripped breaker. b) Not within specifications. 2. Water Supply a) Water supply off or improper water pressure. b) External water filters clogged. 3. Optional Drain Pump (HS-5061) a) Safety switch open. b) Connector loose or disconnected. c) Clogged or kinked hose. d) Defective. 4. Control Switch a) In "OFF" or "WASH" position. b) Bad contacts. 5.
2. Freeze-Up Defrost and clean the icemaker prior to diagnosing freeze-up. Fill out a freeze-up checklist. See the Hoshizaki America Technician's Pocket Guide or contact your local distributor for a copy of the freeze-up checklist. Freeze-Up - Possible Cause Harvest Cycle 1. Evaporator a) Scaled up. b) Damaged. 2. Ice Chute a) Out of position. 3. Control Board See "III.B. Settings and Adjustments." a) Harvest control set too short. Do not adjust. 4. Bin Control See "II.C.
3. Low Ice Production Low Ice Production - Possible Cause Long Harvest Cycle 1. Evaporator a) Scaled up, dirty. 2. Ice Chute a) Out of position. b) Damaged. 3. Refrigerant Charge a) Low. 4. Control Board See "III.B. Settings and Adjustments." a) Thermistor connection loose. 5. Thermistor See "II.E. Thermistor Check" a) Loose, disconnected, or defective. 6. Hot Gas Valve a) Erratic or closed. b) Harvest control moved from factory setting. c) Defective. 7.
III. Control Board • A Hoshizaki exclusive control board is employed in AM series appliances. • All models are pretested and factory adjusted. 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. • Do not touch the electronic devices on the control board or the back of the control board.
A.
B. Settings and Adjustments 1) VR1 Harvest Control VR1 harvest control is for adjustment of the harvest cycle completion temperature. Factory set, do not adjust. NOTICE Do not adjust VR1 harvest control. VR1 harvest control is factory set for proper operation. Adjustment outside of the factory default setting will result in freeze up and/or damage to the appliance. a) Initial Harvest: Terminated by 50 sec. harvest timer. No temperature requirement.
C. LED Lights 1) LED 1 24VAC Green LED 1 flashes to indicate proper 24VAC and continues to flash unless BC is open, control switch is moved to the "OFF" position, or appliance is unplugged. 2) LED 2 Freeze Green LED 2 (PM) turns on at freeze cycle initiation and turns off at freeze cycle termination. 3) LED 3 Harvest Green LED 3 (HGV) turns on at harvest cycle initiation and turns off at harvest cycle termination. D. Control Switch The control switch has three positions: "OFF," "ICE," and "WASH.
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, then unplug the appliance from the electrical outlet before servicing. • CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews are securely in place after the icemaker is serviced.
2. Brazing WARNING • R-134a itself is not flammable at atmospheric pressure and temperatures up to 212°F (100°C). • R-134a itself is not explosive or poisonous. However, when exposed to high temperatures (open flames), R-134a 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.
6) A liquid charge is recommended when charging an R-134a system. Place the service cylinder on the scales; if the service cylinder is not equipped with a dip tube, invert the service cylinder, then place it on the scales. Open the high-side valve on the gauge manifold. 7) Allow the system to charge with liquid until the proper charge weight is met. 8) Close the high-side valve on the gauge manifold, then close the refrigerant access valve (if applicable). Disconnect the gauge manifold hose.
V. Maintenance This appliance must be maintained in accordance with the instruction manual and labels provided with the appliance. Consult with your local Hoshizaki Certified Service Representative about maintenance service. WARNING • Only qualified service technicians should service this appliance. • Failure to install, operate, and maintain the appliance in accordance with this manual will adversely affect safety, performance, component life, and warranty coverage.
B. Optional Drain Pump HS-5061 If the optional drain pump (HS-5061) is installed, test its operation at least once a year as outlined below. Note that the pump has power even when the control switch is in the "OFF" position. 1) Move the control switch to the "OFF" position, then unplug the appliance from the electrical outlet. WARNING! To reduce the risk of electric shock, do not touch the control switch or plug with damp hands. 2) Remove all ice from the ice storage bin. 3) Plug the appliance back in.
VI. Preparing the Icemaker for Periods of Non-Use During extended periods of non-use, extended absences, or in sub-freezing temperatures, follow the instructions below. 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. WARNING Only qualified service technicians should service this appliance.
VII. Disposal This 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 Pressure data is recorded at 5 min. into freezing cycle. The data not in bold should be used for reference only. 1. AM-50BAJ(-DS) 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. AM-50BAJ-AD(ADDS) 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.
B. Wiring Diagrams 1.
2.
