Hoshizaki KM-320MAH Service Manual
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Hoshizaki KM-320MAH Service Manual

Hoshizaki KM-320MAH Service Manual

Modular crescent cuber
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See also: Service Manual , Instruction Manual
Hoshizaki
Hoshizaki America, Inc.
"A Superior Degree
of Reliability"
www.hoshizaki.com
Modular Crescent Cuber
Models
KM-320MAH
KM-320MWH
SERVICE MANUAL
Number: 73132
Issued: 1-24-2006
Revised: 11-30-2006

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Summary of Contents for Hoshizaki KM-320MAH

  • Page 1 Hoshizaki America, Inc. “A Superior Degree of Reliability” www.hoshizaki.com Modular Crescent Cuber Models KM-320MAH KM-320MWH SERVICE MANUAL Number: 73132 Issued: 1-24-2006 Revised: 11-30-2006...
  • Page 2 No such service or maintenance should be undertaken until the technician has thoroughly read this Service Manual. HOSHIZAKI provides this manual primarily to assist qualified service technicians in the service and maintenance of the icemaker. Should the reader have any questions or concerns which have not been satisfactorily addressed, please call or write to the HOSHIZAKI Technical Support Department for assistance.

  • Page 3: Table Of Contents

    This manual should be made available to the technician prior to service or maintenance. I. Specifications ... 5 A. KM-320MAH (air-cooled) ... 5 B. KM-320MWH (water-cooled) ... 6 II. General Information ... 7 A. Construction ... 7 1.
  • Page 4 K. Removal and Replacement of Pump Motor ... 42 L. Removal and Replacement of Spray Tubes ... 42 M. Removal and Replacement of Water Regulating Valve – Water-Cooled Model Only . 43 N. Adjustment Of Water Regulating Valve – Water-Cooled Model Only ... 44 VI.

  • Page 5: Specifications

    I. Specifications SPECIFICATION NO. 05A013 A. KM-320MAH (air-cooled) ITEM: HOSHIZAKI MODULAR CRESCENT CUBER MODEL: KM-320MAH AC SUPPLY VOLTAGE AMPERAGE MINIMUM CIRCUIT AMPACITY MAXIMUM FUSE SIZE APPROXIMATE ICE PRODUCTION PER 24 HR. lbs./day ( kg/day ) Reference without *marks SHAPE OF ICE...

  • Page 6: Km-320Mwh (Water-Cooled)

    B. KM-320MWH (water-cooled) AC SUPPLY VOLTAGE AMPERAGE MINIMUM CIRCUIT AMPACITY MAXIMUM FUSE SIZE APPROXIMATE ICE PRODUCTION PER 24 HR. lbs./day ( kg/day ) Reference without *marks SHAPE OF ICE ICE PRODUCTION PER CYCLE APPROXIMATE STORAGE CAPACITY ELECTRIC & WATER CONSUMPTION ELECTRIC W (kWH/100 lbs.) WATER gal./24HR (gal./100 lbs.)

  • Page 7: General Information

    II. General Information A. Construction 1. KM-320MAH (air-cooled) Evaporator Cleaning Valve Bin Control Thermostat Float Switch Water Pump Compressor Spray Tubes Control Switch Drier Control Box (shown transparent to allow view of other components) Expansion Valve Water Supply Inlet Hot Gas Valve...

  • Page 8: Km-320Mwh (Water-Cooled)

    2. KM-320MWH (water-cooled) Evaporator Cleaning Valve Bin Control Thermostat Float Switch Water Pump Compressor Spray Tubes Control Switch Drier Control Box (shown transparent to allow view of other components) Expansion Valve Water Supply Inlet Hot Gas Valve Water Regulator Condenser...

  • Page 9: Controller Board

    B. Controller Board 1. Solid-State Control • A HOSHIZAKI exclusive solid-state control is employed in KM-320MAH and KM-320MWH Modular Crescent Cubers. • A printed circuit board (hereafter called "controller board") includes a stable and high quality control system. • All models are pretested and factory-adjusted.
  • Page 10 c) High Temperature Safety - 127 ± 7°F (53 ± 4°C) The temperature of the suction line in the refrigerant circuit is limited by the high temperature safety. During the defrost cycle the evaporator temperature rises. The thermistor senses 48°F (9°C) and starts the defrost timer. After the defrost timer counts down to zero, the normal freeze cycle begins.
  • Page 11 The green LEDs 1-4 represent the corresponding relays and energize and sequence 5 seconds from initial startup as follows: Sequence Step 1 Minute Fill Cycle 4 Harvest Cycle Freeze Cycle Reverse Pump Out 1, 3, and 2 {LED 1 – Comp; LED 2 - HGV/CFM; LED 3 – PM; LED 4 - WV} The built in safeties shut down the unit and have alarms as follows: No.
  • Page 12 The application switch located between relay X3 & X4 must be set to match the original board application. Place this switch in the ALP position if there is no white wire supplied to the K1 connector. If there is a white wire, place the switch in the C position. If this switch is placed in the wrong position either the compressor contactor will remain energized with the control switch OFF or the unit will not start.

  • Page 13: Sequence

    3. Sequence 1st Cycle 1. Unit energized and control switch to "ICE" position. Water supply cycle starts. 2. After 1 minute, defrost cycle starts. Water Valve 5. After the first 5 minutes in freeze cycle. Ready to complete freeze cycle when float switch circuit opens.
  • Page 14 2nd Cycle and after with pump drain IMPORTANT Freeze cycle time is limited by the freeze timer factory setting even if the float switch does not open. 1. Float switch opens and signals to complete freeze cycle. Drain timer starts counting. 5.

  • Page 15: Freeze Cycle

    2nd Cycle and after with no pump drain IMPORTANT Freeze cycle time is limited by the freeze timer factory setting even if the float switch does not open. 1. Float switch opens and signals to complete freeze cycle. 4. After the first 5 minutes in freeze cycle. Ready to complete freeze cycle when float switch circuit opens.

  • Page 16: Controls And Adjustments

    4. Controls and Adjustments The dip switch is factory-adjusted to the following positions: Dip Switch No. KM-320MAH KM-320MWH Switch Nos. 1 and 2: Used for adjustment of the defrost timer. The defrost timer starts counting when the thermistor reads a certain temperature at the evaporator outlet.
  • Page 17 a) Defrost Control A thermistor (semiconductor) is used for a defrost control sensor. The resistance varies depending on the suction line temperatures. The thermistor detects the temperature of the evaporator outlet to start the defrost timer. No adjustment is required. If necessary, check for resistance between thermistor leads, and visually check the thermistor mounting, located on the suction line next to the evaporator outlet.
  • Page 18 c) Drain Timer The drain timer is factory-adjusted, and no adjustment is required. Dip Switch Setting T1: Time to drain the water tank T2: Time to restrain defrost completion d) Drain Counter The drain counter is factory-adjusted to drain the water tank every 10 cycles, and no adjustment is required.

  • Page 19: Checking The Controller Board

    e) Freeze Timer Adjust to proper specification, or the unit may not operate correctly. The freeze timer is factory adjusted and no adjustment is required. The setting determines the maximum allowed freeze time to prevent possible freeze-up issues. f) Bin Control When the ambient temperature is below 45°F (7°C), the bin control thermostat operates to stop the icemaker even if the ice storage bin is empty.
  • Page 20 3) Reconnect the float switch connector to the controller board. After the first 5 minutes of the freeze cycle, disconnect the float switch leads from the controller board. At this point, the unit should start the defrost cycle. 4) After step 3), de-energize the unit and confirm that the defrost timer is in the minimum position.

  • Page 21: Technical Information

    III. Technical Information A. Water Circuit and Refrigerant Circuit 1. KM-320MAH...

  • Page 22: Km-320Mwh

    2. KM-320MWH...

  • Page 23: Wiring Diagram

    B. Wiring Diagram 1. KM-320MAH, KM-320MWH Note: Pressure Switch KM-320MAH Cut-out 412 PSIG Cut-in 327 ± 21 PSIG Note: Pressure Switch KM-320MWH Cut-out 384 Cut-in 284 ± 21 PSIG PSIG...

  • Page 24: Timing Chart

    C. Timing Chart *1 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes. See "II.B.4. Controls and Adjustments."...
  • Page 25 *1 The pump motor waits for 2 seconds before starting a drain cycle. See "II.B.4. Controls and Adjustments." *2 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes. See "II.B.4. Controls and Adjustments."...

  • Page 26: Performance Data

    PERFORMANCE DATA NO. 05A013 D. Performance Data ITEM: HOSHIZAKI MODULAR CRESCENT CUBER 1. KM-320MAH MODEL: KM-320MAH APPROXIMATE ICE AMBIENT TEMP. PRODUCTION PER 24 HR. lbs./day kg./day APPROXIMATE ELECTRIC CONSUMPTION watts APPROXIMATE WATER CONSUMPTION PER 24 HR. gal./day /day FREEZING CYCLE TIME min.

  • Page 27: Km-320Mwh

    PERFORMANCE DATA NO. 05A014 2. KM-320MWH ITEM: HOSHIZAKI MODULAR CRESCENT CUBER MODEL: KM-320MWH APPROXIMATE ICE PRODUCTION PER 24 HR. lbs./day kg./day APPROXIMATE ELECTRIC CONSUMPTION watts APPROXIMATE WATER CONSUMPTION PER 24 HR. gal./day /day FREEZING CYCLE TIME min. HARVEST CYCLE TIME min.

  • Page 28: Service Diagnosis

    IV. Service Diagnosis A. No Ice Production Problem Possible Cause [1] The icemaker will not a)Power Supply start. b)Fuse (Inside fused disconnect, if any) c) Control Switch d)Bin Control Thermostat 1. Tripped with bin filled e)High Pressure Control 1. Bad contacts. f) Transformer g)Wiring to Controller Board...
  • Page 29 Problem Possible Cause j) Water Supply Line k) Water Solenoid l) Controller Board m)Interlock Switch (Cleaning Valve) [2] Water continues to a)Float Switch be supplied, and the icemaker will not start. b)Controller Board c) Contactor [3] Compressor will a)Wash Switch not start or stops operating.
  • Page 30 Problem Possible Cause c) Overload Protector d)Starter e)Start Capacitor or Run Capacitor f) Magnetic Contactor g)Compressor h)Controller Board i) Water Regulator [4] Water continues to a)Water Solenoid Valve be supplied in freeze cycle. b)Controller Board [5] No water comes from a)Water Supply Line spray tubes.

  • Page 31: Evaporator Is Frozen Up

    Problem Possible Cause d)Pump Motor e)Controller Board [6] Fan motor will a)Fan Motor not start, or is not operating. b)Controller Board [7] All components a)Refrigerant run, but no ice is produced. b)Compressor c) Hot Gas Solenoid Valve 1. Continues to open in d)Line Valve e)Water Supply Line (water-cooled model)
  • Page 32 Problem Possible Cause c) Controller Board [2]All ice formed on a) Evaporator evaporator does not b) Water Supply Line fall into bin in harvest cycle. c) Water Filter System d) Water Solenoid Valve e) Ambient and/or water temperature. f) Line Valve g) Thermistor h) Controller Board [3]Other...

  • Page 33: Low Ice Production

    C. Low Ice Production Problem Possible Cause [1] Freeze cycle time is a) See chart A.[3] and check dirty air filter or condenser, ambient or water long. temperature, water pressure, water regulator, and refrigerant charge. b) See chart B.[1] and check float switch, water solenoid valve and controller board.

  • Page 34: Removal And Replacement Of Components

    5) Disconnect the vacuum pump and attach a refrigerant service cylinder to the high- side line. Remember to loosen the connection and purge the air from the hose. See the nameplate for the required refrigerant charge. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.

  • Page 35: Brazing

    8) If necessary, add any remaining charge to the system through the low-side. Use a throttling valve or liquid dispensing device to add the remaining liquid charge through the low-side access port with the unit running. 9) Close the two refrigerant access valves and disconnect the hoses and service manifold. 10) Cap the access valves to prevent a possible leak.

  • Page 36: Removal And Replacement Of Compressor

    C. Removal and Replacement of Compressor Always install a new drier every time the sealed refrigeration system is opened. Do not replace the drier until after all other repair or replacement has been made. Note: When replacing a compressor with a defective winding, be sure to install the new start capacitor and start relay supplied with the replacement compressor.

  • Page 37: Removal And Replacement Of Drier

    D. Removal and Replacement of Drier Always install a new drier every time the sealed refrigeration system is opened. Do not replace the drier until after all other repair or replacement has been made. 1) Turn off the power supply. 2) Remove the panels.

  • Page 38: Removal And Replacement Of Hot Gas Valve And Line Valve

    6) Braze the new expansion valve, with nitrogen gas flowing at a pressure of 3 to 4 PSIG. 1. Do not heat the wall. Place a steel barrier for protection. 2. Always protect the valve body by using a damp cloth to prevent the valve from overheating.

  • Page 39: Removal And Replacement Of Evaporator

    7) Install a new drier. 8) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles. 9) Evacuate the system and charge it with refrigerant. See the nameplate for the required refrigerant charge. 10) Cut the leads of the solenoid allowing enough lead length to reconnect using closed end connectors.

  • Page 40: Removal And Replacement Of Thermistor

    H. Removal and Replacement of Thermistor 1. Fragile, handle very carefully. 2. Always use a recommended sealant (High Thermal Conductive Type), Model KE4560RTV manufactured by SHINETSU SILICONE, Part Code 60Y000-11, or Part Code 4A0683-01 equivalent. 3. Always use a recommended foam insulation (Non-absorbent Type) or equivalent.

  • Page 41: Removal And Replacement Of Fan Motor

    I. Removal and Replacement of Fan Motor Note: When replacing a fan motor with defective winding, it is recommended that a new capacitor be installed. 1) Turn off the power supply. 2) Remove the panels. 3) Remove the closed end connectors from the fan motor leads. 4) Remove the fan motor bracket and fan motor.

  • Page 42: Removal And Replacement Of Pump Motor

    K. Removal and Replacement of Pump Motor 1) Turn off the power supply. 2) Remove the front panel. 3) Remove the base cover. 4) Drain the water tank by removing one end of the pump tubing. 5) Replace the removed parts in their correct positions. 6) Disconnect the pump suction and discharge hoses.

  • Page 43: Removal And Replacement Of Water Regulating Valve - Water-Cooled Model Only

    M. Removal and Replacement of Water Regulating Valve – Water-Cooled Model Only Always install a new drier every time the sealed refrigeration system is opened. Do not replace the drier until after all other repair or replacement has been made. 1) Turn off the power supply.

  • Page 44: Adjustment Of Water Regulating Valve - Water-Cooled Model Only

    N. Adjustment Of Water Regulating Valve – Water-Cooled Model Only The water regulating valve (also called "water regulator") is factory-adjusted. No adjustment is required under normal use. Adjust the water regulator, if necessary, using the following procedure. 1) Attach a pressure gauge to the high-side line of the system. Or prepare a thermometer to check for the condenser drain temperature.

  • Page 45: Cleaning And Maintenance Instructions

    VI. Cleaning and Maintenance Instructions Ensure all components, fasteners and thumbscrews are securely in place after any maintenance or cleaning is done to the equipment. A. Preparing the Icemaker for Long Storage When shutting off the icemaker for an extended time, drain out all water from the water tank and remove the ice from the storage bin.
  • Page 46 3. Drain the potable water tank: 1) Turn off the power supply. 2) Move the control switch to the "OFF" position. 3) Drain the water tank by removing the base cover and one end of the pump tubing. See Fig. 4. 4) Replace the removed parts in their correct positions.

  • Page 47: Cleaning And Sanitizing Instructions

    Ensure all components, fasteners and thumbscrews are securely in place after any maintenance or cleaning is done to the equipment. 1. HOSHIZAKI recommends cleaning this unit at least once a year. More frequent cleaning, however, may be required in some existing water conditions.

  • Page 48: Cleaning Procedure

    1. Cleaning Procedure 1) Dilute approximately 16 fl. oz. of Hoshizaki "Scale Away" with 3 gal. of warm water. 2) Remove all ice from the evaporator and the storage bin. Note: To remove cubes on the evaporator, turn off the power supply and turn it on after 3 minutes.

  • Page 49: Sanitizing Procedure - Following Cleaning Procedure

    15) Move the control switch to the "ICE" position. 16) Close the cleaning valve. Note: The icemaker will not operate unless the cleaning valve is completely closed. 17) Replace the front panel in its correct position. 18) Turn on the power supply to fill the water tank with water. 19) Turn off the power supply after 3 minutes.

  • Page 50: Maintenance

    C. Maintenance This icemaker must be maintained individually, referring to the instruction manual and labels provided with the icemaker. 1) Stainless Steel Exterior To prevent corrosion, wipe the exterior occasionally with a clean and soft cloth. Use a damp cloth containing a neutral cleaner to wipe off oil or dirt build up. 2) Storage Bin and Scoop •...

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Km-320mwh

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