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Hoshizaki KM-280MAH Service Manual

Modular crescent cuber
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MODULAR CRESCENT CUBER
HOSHIZAKI
MODEL
KM-280MAH
KM-280MWH
SERVICE MANUAL
NO.
ISSUED:
AUG. 15, 2004
REVISED:
73117

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Summary of Contents for Hoshizaki KM-280MAH

  • Page 1 MODULAR CRESCENT CUBER KM-280MAH KM-280MWH SERVICE MANUAL HOSHIZAKI MODEL 73117 ISSUED: AUG. 15, 2004 REVISED:...
  • Page 2 No 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

    1. WATER CIRCUIT AND REFRIGERANT CIRCUIT ... 24 [a] KM-280MAH ... 24 [b] KM-280MWH ... 25 2. WIRING DIAGRAMS ... 26 [a] KM-280MAH and KM-280MWH ... 26 3. TIMING CHART ... 28 4. PERFORMANCE DATA ... 30 [a] KM-280MAH ... 30 [b] KM-280MWH Serial #L00001E - M10134C ...
  • Page 4 IV. SERVICE DIAGNOSIS... 33 1. NO ICE PRODUCTION... 33 2. EVAPORATOR IS FROZEN UP ... 36 3. LOW ICE PRODUCTION ... 37 4. ABNORMAL ICE ... 37 5. OTHERS ... 37 V. REMOVAL AND REPLACEMENT OF COMPONENTS ... 38 1. SERVICE FOR REFRIGERANT LINES ... 38 [a] REFRIGERANT RECOVERY ...

  • Page 5: Specifications

    SPECIFICATIONS KM-280MAH (Air-cooled) Note: We reserve the right to make changes in specifications and design without prior notice.

  • Page 6: 2A. Km-280Mwh (Water-Cooled) Serial #L00001E - M10134C

    Serial #L00001E- M10134C KM-280MWH (Water-cooled) Note: We reserve the right to make changes in specifications and design without prior notice.

  • Page 7: 2B. Km-280Mwh (Water-Cooled) Serial #M20315D

    Serial #M20315D - 2b. KM-280MWH (Water-cooled) Note: We reserve the right to make changes in specifications and design without prior notice.

  • Page 8: General Information

    GENERAL INFORMATION 1. CONSTRUCTION [a] KM-280MAH (Air-cooled) Spray Tubes Control Switch Bin Control Thermostat (except models with Mechanical Bin Control) Expansion Valve Compressor Float Switch Water Pump Mechanical Bin Control (except models with Thermostat) Water Supply Inlet Condenser Hot Gas Valve...

  • Page 9: [B] Km-280Mwh (Water-Cooled)

    [b] KM-280MWH (Water-cooled) Spray Tubes Control Switch Bin Control Thermostat (except models with Mechanical Bin Control) Expansion Valve Compressor Float Switch Water Pump Mechanical Bin Control (except models with Thermostat) Water Supply Inlet Water Regulator Hot Gas Valve Drier Control Box...

  • Page 10: Controller Board

    2. CONTROLLER BOARD [a] SOLID-STATE CONTROL 1) A HOSHIZAKI exclusive solid-state control is employed in Modular Crescent Cubers. 2) A Printed Circuit Board (hereafter called “Controller Board”) includes a stable and high quality control system. 3) All models are pretested and factory-adjusted.
  • Page 11 2) Defrost Timer The defrost cycle starts when the Float Switch opens and completes the freeze cycle. But the Defrost Timer does not start counting until the Thermistor senses 48°F at the Evapora- tor outlet. The period from the end of the freeze cycle up to the point of the Thermistor's sensing varies depending on the ambient and water temperatures.
  • Page 12 The green LED’s 1-4 represent the corresponding relays and energize and sequence 5 seconds from initial start-up as follows: Sequence Step LED’s on Length: 1 Minute Fill Cycle LED4 Harvest Cycle LED1, 4, & 2 Freeze Cycle LED1 Reverse Pump Out LED1, 3, &...
  • Page 13 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 ener- gized with the control switch OFF, or the unit will not start.

  • Page 14: [C] Sequence

    [c] SEQUENCE 1st Cycle 1. Unit energized and Control Switch to “ICE” position. Water supply cycle starts. 2. After 1 minute, Defrost cycle starts. 5. After the first 5 minutes in freeze cycle. Ready to complete freeze cycle when Float Switch circuit opens.
  • Page 15 2nd Cycle and after with pump drain IMPORTANT Freeze cycle time is limited to 60 minutes even if Float Switch does not open. 1. Float Switch opens and signals to complete freeze cycle. Drain timer starts counting. 5. After the first 5 minutes in freeze cycle. Ready to complete freeze cycle when Float Switch circuit opens.
  • Page 16 2nd Cycle and after with no pump drain IMPORTANT Freeze cycle time is limited to 60 minutes even if 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 17: [D] Controls And Adjustments

    [d] CONTROLS AND ADJUSTMENTS The Dip Switch is factory-adjusted to the following positions: FOR MODELS WITH MECHANICAL BIN CONTROL: DIP SWITCH NO. KM-280MAH OFF OFF OFF KM-280MWH FOR MODELS WITH THERMOSTAT : DIP SWITCH NO. KM-280MAH OFF OFF OFF KM-280MWH Switch Nos.
  • Page 18 1) 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 19 2) Defrost Timer No adjustment is required under normal use, as the Defrost Timer is adjusted to the suitable position. However, if necessary when all the ice formed on the Evaporator does not fall into the bin in the harvest cycle, adjust the Defrost Timer to longer setting by adjusting the Dip Switch (No.
  • Page 20 SETTING Dip Switch No. 5 5) Freeze Timer Adjust to proper specification, or the unit may not operate correctly. Two new dip switches numbered 9 and 10 have been added to the improved “E” board to better prevent possible freeze ups. These settings come factory set to the default setting of 60 min.

  • Page 21: [E] Checking Controller Board

    MODELS WITH MECHANICAL BIN CONTROL Dip Switch No. 7 must be set to the ON position. If No. 7 is set to the OFF position, the machine will run continuously, causing a freeze-up condition. No adjustment is required. The Bin Control is factory-adjusted. [e] CHECKING THE CONTROLLER BOARD 1) Visually check the sequence with the icemaker operating.

  • Page 22: Mechanical Bin Control

    3) Check the Controller Board by using test program of the Controller Board. The Output Test Switch “S3” provides a relay sequence test. With power OFF, place S3 on and switch power to ICE. The correct lighting sequence should be none, 2, 3, 4, 1, and 4, normal sequence every 5 seconds.

  • Page 23: [C] Troubleshooting

    [c] TROUBLESHOOTING (MECHANICAL BIN CONTROL ONLY) 1) Machine will not start (i) Move dip switch No. 7 to the “OFF” position. If the machine starts up within a few seconds, the bin control is the likely problem. If the machine does not start up, refer to Section “IV.

  • Page 24: Technical Information

    III. TECHNICAL INFORMATION 1. WATER CIRCUIT AND REFRIGERANT CIRCUIT [a] KM-280MAH...

  • Page 25: [B] Km-280Mwh

    [b] KM-280MWH...

  • Page 26: Wiring Diagrams

    2. WIRING DIAGRAMS [a] KM-280MAH (with auxiliary codes L-0, M-0, and M-1) and KM-280MWH (with auxiliary codes L-0, M-0, and M-1) Note: Pressure Switch Cut-out 412 ± Cut-in 327 ± 21 PSIG PSIG Cut-out Cut-in 384 ± PSIG 284 ± 21 PSIG...
  • Page 27 KM-280MAH (with auxiliary codes M-2 and after) and KM-280MWH (with auxiliary codes M-2 and after)

  • Page 28: Timing Chart

    3. TIMING CHART...

  • Page 30: Performance Data

    PERFORMANCE DATA [a] KM-280MAH Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not in bold should be used for reference only. We reserve the right to make changes in specifications and design without prior notice.

  • Page 31: [B] Km-280Mwh Serial #L00001E - M10134C

    Serial #L00001E- M10134C [b] KM-280MWH Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not in bold should be used for reference only. We reserve the right to make changes in specifications and design without prior notice.

  • Page 32: [C] Km-280Mwh Serial #M20315D

    Serial #M20315D - [c] KM-280MWH Note: Pressure data is recorded at 5 minutes into freeze cycle. The data not with * should be used for reference only. We reserve the right to make changes in specifications and design without prior notice.

  • Page 33: Service Diagnosis

    SERVICE DIAGNOSIS 1. NO ICE PRODUCTION PROBLEM [1] The icemaker a) Power Supply will not start b) Fuse (Inside Fused Disconnect, if any) c) Control Switch d) Bin Control Thermostat For mechanical bin control see “II. 3. [c]” e) High Pressure Control f) Transformer g) Wiring to...
  • Page 34 PROBLEM l) Controller Board m) Interlock Switch (Cleaning Valve) [2] Water a) Float switch continues to be supplied, and the ice- maker will not b) Controller Board start. [3] Compressor a) Wash Switch b) High Pressure Controller c) Water Regulator d) Overload Protector e) Starter f) Start Capacitor or...
  • Page 35 PROBLEM [5] No water a) Water Supply Line comes from Spray Tubes. Water Pump b) Water Solenoid will not start, or Valve freeze cycle time is too c) Water System short. d) Pump Motor e) Controller Board [6] Fan Motor will a) Fan Motor not start, or is not operating.

  • Page 36: Evaporator Is Frozen Up

    2. EVAPORATOR IS FROZEN UP PROBLEM [1] Freeze cycle a) Float Switch time is too long. b) Water Solenoid Valve c) Controller Board [2] All ice formed a) Evaporator on Evaporator b) Water Supply Line does not fall into bin in c) Water Solenoid harvest cycle.

  • Page 37: Low Ice Production

    3. LOW ICE PRODUCTION PROBLEM [1] Freeze cycle a) See chart 1 - [3], and check dirty Air Filter or Condenser, ambient or water time is long. temperature, water pressure, Water Regulator or refrigerant charge. b) See chart 2 - [1], and check Float Switch, Water Solenoid Valve or Controller Board.

  • Page 38: Removal And Replacement Of Components

    REMOVAL AND REPLACEMENT OF COMPONENTS Ensure all components, fasteners and thumbscrews are securely in place after the equipment is serviced. 1. The Polyol Ester (POE) oils used in R-404A units can absorb moisture quickly. Therefore it is important to prevent moisture from entering the system when replacing or servicing parts.

  • Page 39: Brazing

    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 refriger- ant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.

  • Page 40: Removal And Replacement Of Compressor

    3. 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 41 15) Evacuate the system, and charge it with refrigerant. For air-cooled and water-cooled models, see the Nameplate for the required refrigerant charge. For remote air-cooled models, see the Charge Label in the machine compartment. 16) Connect the Terminals, and replace the Terminal Cover in its correct position. 17) Replace the panels in their correct positions.

  • Page 42: Removal And Replacement Of Drier

    4. 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 43: Removal And Replacement Of Hot Gas Valve And ............................... Line Valve

    3) Recover the refrigerant and store it in an approved container. 4) Remove the insulation and the Expansion Valve Bulb on the suction line. 5) Remove the Expansion Valve Cover, and disconnect the Expansion Valve using brazing equipment. 6) Braze the new Expansion Valve, with nitrogen gas flowing at the pressure of 3 - 4 PSIG.
  • Page 44 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. 3) Recover the refrigerant and store it in an approved container. 4) Remove the screw and the Solenoid.

  • Page 45: Removal And Replacement Of Evaporator

    7. REMOVAL AND REPLACEMENT OF EVAPORATOR Always install a new Drier every time the sealed refrigeration system is opened. Do not replace the Drier until after all other repairs or replacement have been made. 1) Turn off the power supply. 2) Remove the panels and the Top Insulation over the Evaporator.

  • Page 46: Removal And Replacement Of Water-Regulating Valve

    8. 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 47: Adjustment Of Water Regulating Valve - Water-Cooled Model Only

    9. 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 procedures. 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 48: Removal And Replacement Of Thermistor

    10. 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 or equivalent. 3. Always use a recommended foam insulation (Non-absorbent Type) or equivalent.

  • Page 49: Removal And Replacement Of Fan Motor

    Note: For models with the Liquid Bypass, the Thermistor should be located upstream from the Liquid Bypass outlet, and its end should be 4-3/4" or more away from the outlet. See Fig. 3. Flow 10) Secure the insulation using the Plastic Cable Ties. 11) Connect the Thermistor leads through the bushing of the Control Box to the K3 Connector on the Controller Board.

  • Page 50: Removal And Replacement Of Water Valve

    6) Install the new Fan Motor, and replace the removed parts in the reverse order of which they were removed. 7) Replace the panels in their correct positions. 8) Replace the Junction Box Cover in its correct position (Remote Air-cooled model). 9) Turn on the power supply.

  • Page 51: Removal And Replacement Of Spray Tubes

    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. 7) Remove the screws and the Pump Motor Bracket. 8) Remove the closed end connectors from the Pump Motor leads.

  • Page 52: Cleaning And Maintenance Instructions

    CLEANING AND MAINTENANCE INSTRUCTIONS Ensure all components, fasteners and thumbscrews are securely in place after any maintenance or cleaning is done to the equipment. 1. 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 53 9) Attach compressed air or carbon dioxide supply to the Condenser Water Line Drain Valve. 10) Quickly blow the water-cooled Condenser out, using compressed air or carbon [2] Remove the water from the potable water supply line: 1) Remove the Front Panel. (Except water-cooled model) 2) Move the Control Switch, on the Control Box, to the “OFF”...

  • Page 54: Cleaning

    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 condi- tions.

  • Page 55: [A] Cleaning Procedure

    [a] CLEANING PROCEDURE 1) Dilute 16 fl. oz. of the recommended cleaner Hoshizaki “Scale Away” or “LIME-A-WAY” (Economics Laboratory, Inc.) with 3 gal. of 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 56 19) Replace the Front Panel in its correct position. 20) Turn on the power supply to fill the Water Tank with water. 21) Turn off the power supply after 3 minutes. 22) Remove the Front Panel, and fully open the Cleaning Valve. 23) Move the Control Switch to the “Wash”...

  • Page 57: [B] Sanitizing Procedure

    [b] SANITIZING PROCEDURE - Following Cleaning Procedure 1) Dilute a 5.25 % Sodium Hypochlorite solution with water (Add 1.5 fl. oz. of sanitizer to 3 gal. of water). 2) Remove the Insulation Panel, if it is in its usual position. 3) Pour the sanitizing solution into the Water Tank.

  • Page 58: Maintenance

    3. 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-280mwh

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