Hoshizaki KMD-450MAH Service Manual
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Hoshizaki KMD-450MAH Service Manual

Modular crescent cuber
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Hoshizaki
Hoshizaki America, Inc.
"A Superior Degree
of Reliability"
www.hoshizaki.com
Modular Crescent Cuber
Models
KMD-450MAH
KMD-450MWH
SERVICE MANUAL
™
Number: 73161
Issued: 9-3-2009

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  • Page 1 Hoshizaki Hoshizaki America, Inc. Modular Crescent Cuber Models KMD-450MAH KMD-450MWH SERVICE MANUAL “A Superior Degree of Reliability” www.hoshizaki.com ™ Number: 73161 Issued: 9-3-2009...
  • Page 2 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, write, or send an e-mail message to the Hoshizaki Technical Support Department for assistance. HOSHIZAKI AMERICA, INC.

  • Page 3: Table Of Contents

    CONTENTS Important Safety Information ....................6 I. Specifications ........................7 A. Icemaker ........................7 1. KMD-450MAH (air-cooled) ..................7 2. KMD-450MWH (water-cooled) ................. 8 II. General Information ......................9 A. Construction ........................9 1. KMD-450MAH (air-cooled) ..................9 2. KMD-450MWH (water-cooled) ................10 B.
  • Page 4 WASH ....................... 25 III. Technical Information ...................... 26 A. Water Circuit and Refrigeration Circuit ................ 26 1. KMD-450MAH (air-cooled) ..................26 2. KMD-450MWH (water-cooled) ................27 B. Wiring Diagram and Multimeter Access Points ..............28 1. Wiring Diagram ....................... 28 2.
  • Page 5 H. Removal and Replacement of Water Regulating Valve (water-cooled model) ..... 58 I. Adjustment of Water Regulating Valve (water-cooled model) ........59 J. Removal and Replacement of Thermistor ..............60 K. Removal and Replacement of Fan Motor (air-cooled and remote air-cooled models) . 61 L.

  • Page 6: Important Safety Information

    Important Safety Information Throughout this manual, notices appear to bring your attention to situations which could result in death, serious injury, or damage to the unit. WARNING Indicates a hazardous situation which could result in death or serious injury. CAUTION Indicates a situation which could result in damage to the unit.

  • Page 7: Specifications

    I. Specifications A. Icemaker 1. KMD-450MAH (air-cooled) AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V) AMPERAGE 10.0 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP.

  • Page 8: Kmd-450Mwh (Water-Cooled)

    2. KMD-450MWH (water-cooled) AC SUPPLY VOLTAGE 115-120/60/1 (3 wire with netrual for 115V) AMPERAGE 8.5A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 15 A MAXIMUM FUSE SIZE 15 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR.

  • Page 9: General Information

    II. General Information A. Construction 1. KMD-450MAH (air-cooled) Wash Valve Water Guide Spray Guide Water Supply Inlet Spray Tube Expansion Valve Junction Box Hot Gas Valve Condenser Condenser Fan Motor Inlet Water Valve Control Switch Service Switch Drain Valve Water Tank...

  • Page 10: Kmd-450Mwh (Water-Cooled)

    2. KMD-450MWH (water-cooled) Wash Valve Water Guide Water Supply Inlet Spray Guide Expansion Valve Spray Tube Junction Box Hot Gas Valve Condenser Inlet Water Water Regulator Valve Control Switch Drain Valve Service Switch Compressor Drier Water Tank Pump Motor Control Box Float Switch Bin Control...

  • Page 11: Sequence Of Operation

    F/S to refill the water tank during the freeze cycle. The KMD-450MAH and KMD-450MWH use a single F/S and do not refill. For details, see "II.C.3.h) Float Switch Selector (S2 dip switch 2)" and "II.C.3.i) Refill Counter (S2 dip switch 3 &...

  • Page 12: D) Pump-Out Cycle

    34°F (1°C), the control board reads a 5.8 kΩ signal from the thermistor and de-energizes PM for 10 seconds. The anti-slush control is deactivated on the KMD-450MAH and KMD-450MWH. CAUTION! Do not adjust S2 dip switch 6 out of the factory default position on this model.
  • Page 13 switch 1)." When the pump-out/drain selector is set to pump-out, PM takes water from the tank and forces it through DV and down the drain. When the pump-out/drain selector is set to drain, water drains by gravity through DV. CAUTION! Do not adjust S2 dip switch 1 out of the factory default position on this model.

  • Page 14: Sequence Flow Chart

    2. Sequence Flow Chart...

  • Page 15: Control Board

    C. Control Board • A Hoshizaki exclusive solid-state control board is employed in KMD-450MAH and KMD-450MWH Modular Crescent Cubers. • All models are pretested and factory set. • For a control board check procedure, see "IV.B. Control Board Check." CAUTION 1. The control board is fragile; handle very carefully. 2. 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 unit before handling or replacing the control board.

  • Page 16: Control Board Layout

    1. Control Board Layout "H" Control Board • Relay LEDs (6) (indicate which relays are energized • K7 Connector as listed below) Transformer • LED 5 (X1 Relay) Compressor (Comp) Fan Motor-Remote (FMR) • LED 6 (X2 Relay) • K3 Connector Hot Gas Valve (HGV) Magnetic Contactor Fan Motor (FM) Liquid Line Valve (LLV)

  • Page 17: Features

    2. Features a) Maximum Water Supply Period - 6 minutes The inlet water valve is open during harvest for 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (harvest pump timer (S1 dip switch 7 & 8)), whichever is shorter.

  • Page 18: F) Led Lights And Audible Alarm Safeties

    f) LED Lights and Audible Alarm Safeties At startup, a 5-second delay occurs to stabilize the circuit. The "POWER OK" LED indicates proper control voltage and remains on unless a control voltage problem occurs. The "POWER OK" LED flashes continuously when the bin is full and PM and DV energize for a maximum of 5 minutes to drain the water tank.

  • Page 19: Controls And Adjustments

    Dip switches are factory set. Failure to maintain factory settings may adversely affect performance and warranty coverage. For more information, contact Hoshizaki Technical Support at 1-800-233-1940. a) Default Dip Switch Settings The dip switches are factory set to the following positions: S1 Dip Switch Dip Switch No.

  • Page 20: B) Harvest Timer (S1 Dip Switch 1 & 2)

    However, a setting longer than the factory setting may be advised in cases where the flush provided at harvest needs to be prolonged for extra cleaning. Before changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for recommendations. Keep in mind that setting the harvest timer to a longer setting decreases 24-hour production.

  • Page 21: D) Pump-Out Frequency Control (S1 Dip Switch 5 & 6)

    d) 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, and generally no adjustment is required. However, if the icemaker needs a pump-out more often due to local water conditions, 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 2, 5, or 10 cycles.

  • Page 22: F) Freeze Timer (S1 Dip Switch 9 & 10)

    In this case, see "IV.F.3. Low Ice Production" for possible solutions. The freeze timer is factory set, and generally no adjustment is required. Before changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for recommendations.

  • Page 23: H) Float Switch Selector (S2 Dip Switch 2)

    The float switch selector allows for single or double float switch applications. In double float switch applications, the float switch selector setting determines whether the lower or upper switch is used to initiate refills during the freeze cycle. The KMD-450MAH and KMD-450MWH use a single float switch and do not refill.

  • Page 24: Bin Control

    Recommended is recommended. When installed on a standard Thumbscrews Hoshizaki storage bin, either set of holes is Bin Control acceptable. See Fig. 1. The bin control should be mounted flush with the dispenser unit/storage bin Some Parts Fig.

  • Page 25: Switches

    G. Switches The "control switch" and the "service switch" are used to control operation 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.

  • Page 26: Technical Information

    III. Technical Information A. Water Circuit and Refrigeration Circuit 1. KMD-450MAH (air-cooled) Condenser Spray Tubes Evaporator High Pressure Inlet Water Valve Switch Water Supply Wash Valve Drier Drain Valve Insulation Tube Thermistor Heat Exchanger Strainer Suction Line Hot Gas Valve...

  • Page 27: Kmd-450Mwh (Water-Cooled)

    2. KMD-450MWH (water-cooled) Water Regulating Condenser Valve Drain or Return Inlet Water Valve Spray Tubes Evaporator Water Supply Water High Supply Pressure Drier Switch Wash Valve Drain Valve Insulation Tube Thermistor Heat Exchanger Strainer Suction Line Hot Gas Pump Motor Valve Float Access...

  • Page 28: Wiring Diagram And Multimeter Access Points

    B. Wiring Diagram and Multimeter Access Points 1. Wiring Diagram a) KMD-450MAH (air-cooled) and KMD-450MWH (water-cooled) Note: A diagnostic connector and a compressor terminal block are included in the control box to allow easier access for a multimeter. For details see, "III.B.2.

  • Page 29: Multimeter Access Points

    2. Multimeter Access Points a) Diagnostic Connector A diagnostic connector is included in the control box to allow easier access for a multimeter. The diagnostic connector terminals correspond to components as outlined in Fig. 2. Motor, Liquid Pump Control Line Valve Motor Switch...

  • Page 30: Performance Data

    C. Performance Data 1. KMD-450MAH (air-cooled) APPROXIMATE ICE WATER TEMP. (ºF/ºC) AMBIENT TEMP. PRODUCTION PER 24 HR. (ºF/ºC) 50/10 70/21 90/32 70/21 80/27 90/32 lbs./day kg./day 100/38 APPROXIMATE ELECTRIC 70/21 CONSUMPTION 80/27 90/32 watts 100/38 APPROXIMATE WATER 70/21 0.73 0.60 0.53...

  • Page 31: Kmd-450Mwh (Water-Cooled)

    2. KMD-450MWH (water-cooled) APPROXIMATE ICE WATER TEMP. (ºF/ºC) AMBIENT TEMP. PRODUCTION PER 24 HR. (ºF/ºC) 50/10 70/21 90/32 70/21 80/27 90/32 lbs./day kg./day 100/38 APPROXIMATE ELECTRIC 70/21 CONSUMPTION 80/27 90/32 watts 100/38 APPROXIMATE WATER 70/21 1.74 1.89 2.58 CONSUMPTION PER 24 HR. 80/27 1.86 2.09...

  • Page 32: Service Diagnosis

    IV. Service Diagnosis WARNING 1. This unit should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. 2. Risk of electric shock. Use extreme caution and exercise safe electrical practices.
  • Page 33 F/S to refill the water tank during the freeze cycle. The KMD-450MAH and KMD-450MWH use a single F/S and do not refill. For details, see "II.C.3.h) Float Switch Selector (S2 dip switch 2)" and "II.C.3.i) Refill Counter (S2 dip switch 3 &...
  • Page 34 PM for 10 seconds. The anti-slush control is deactivated on the KMD-450MAH and KMD-450MWH. CAUTION! Do not adjust S2 dip switch 6 out of the factory default position on this model. This dip switch must be left in the factory default position or this unit will not operate correctly.
  • Page 35 The first pump-out occurs after the 1st freeze cycle, then every 10th cycle thereafter. The pump-out frequency is factory set, and generally no adjustment is required. However, if the icemaker needs a pump-out more often due to local water conditions, the pump-out frequency can be adjusted.

  • Page 36: Control Board Check

    B. Control Board Check Before replacing a control board 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 the control board is in alarm (beeping), press the "ALARM RESET" button on the control board with power on.

  • Page 37: Bin Control Check And Cleaning

    C. Bin Control Check and Cleaning 1. Bin Control Check To check the bin control, 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, then clear any ice away from the bin control. 4) Disconnect the wire connector from the control board K1 nine-pin connector.

  • Page 38: Float Switch Check And Cleaning

    5) Remove the actuator paddle from the switch mount. See Fig. 5. 6) Wipe down the bin control with a mixture of 1 part recommended cleaner Hoshizaki "Scale Away" and 25 parts warm water. Rinse the parts thoroughly with clean water.

  • Page 39: Float Switch Cleaning

    6) Reconnect the wire connector to the control board K1 nine-pin connector, then replace the control box cover in its correct position. 7) Move the control switch to the "ICE" position. Replace the front panel in its correct position, then turn on the power supply. After 1 minute, the 1-minute fill cycle should end and the initial harvest cycle should begin.
  • Page 40 See Fig. 8. 11) Wipe down the float switch housing, shaft, float, and retainer rod with a mixture of 1 part Hoshizaki "Scale Away" and 25 parts warm water. Rinse the parts thoroughly with clean water.

  • Page 41: Thermistor Check

    E. 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 control box cover. 4) Disconnect the wire connector from the control board K1 nine-pin connector. See "II. C.1.

  • Page 42: Diagnostic Charts

    F. Diagnostic Charts 1. No Ice Production Problem Possible Cause Remedy [1] The icemaker will not a) Power Supply 1. Off, blown fuse, or 1. Turn on, replace, or reset. start. tripped breaker. 2. Loose connection. 2. Tighten. 3. Bad contacts. 3.
  • Page 43 Problem Possible Cause Remedy [1] The icemaker will not j) Hot Gas Valve 1. Continues to open 1. Check for hot gas valve start. (continued) in freeze cycle and stuck open and replace. freeze timer safety operates (3 beep alarm). k) Inlet Water Valve 1.
  • Page 44 Problem Possible Cause Remedy [4] Water continues to a) Water Pressure 1. Too high. 1. Reduce. be supplied in freeze b) Inlet Water Valve 1. Diaphragm does not 1. Check for water leaks with cycle. close. icemaker off. c) Control Board 1.

  • Page 45: Evaporator Is Frozen Up

    Problem Possible Cause Remedy [8] All components g) Headmaster (C.P.R.) 1. Not operating properly 1. Replace headmaster. run, but no ice is (remote condenser and liquid line produced. (continued) unit) temperature too warm. h) Water Supply Line 1. Condenser water 1.
  • Page 46 Problem Possible Cause Remedy [2]All ice formed on e) Inlet Water Valve 1. Dirty mesh filter or 1. Clean. evaporator does not orifice. fall into bin in harvest 2. Diaphragm does not 2. Check for water leaks with cycle. (continued) close.

  • Page 47: Low Ice Production

    Problem Possible Cause Remedy [3]Other. a) Ice Cube Guide 1. Out of position. 1. Place in position. b) Bin Control 1. Movement restricted. 1. Check and free. 2. See "IV.C. Bin Control 2. Defective. Check and Cleaning." 3. Low Ice Production Problem Possible Cause Remedy...

  • Page 48: Abnormal Ice

    Problem Possible Cause Remedy [1] Freeze cycle time is o) Control Board 1. Refill counter (S2 dip 1. Set to factory default long. (continued) switch 3 & 4) not in position. See "II.C.3.a) the factory default Default Dip Switch position. Settings."...

  • Page 49: Other

    Problem Possible Cause Remedy [1] Small cubes. f) Control Board 1. Defective. 1. See "IV.B. Control Board (continued) Check." [2] Cloudy or irregular a) Evaporator 1. Frozen up. 1. See chart 2. cubes. 2. Scaled up. 2. Clean 3. Damaged. 3.

  • Page 50: Removal And Replacement Of Components

    V. Removal and Replacement of Components WARNING 1. This unit should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. 2. Move the control switch to the "OFF" position and turn off the power supply before servicing.

  • Page 51: Brazing

    2. Brazing WARNING 1. R-404A itself is not flammable at atmospheric pressure and temperatures up to 176°F (80°C). 2. 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.

  • Page 52: Removal And Replacement Of Compressor

    For air-cooled and water-cooled models, see the nameplate for the required refrigerant charge. For remote air-cooled model, see the rating label inside the icemaker. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets ARI Standard 700 (latest edition) be used.

  • Page 53: Removal And Replacement Of Expansion Valve

    9) Place the compressor in position and secure it using the bolts and washers. 10) Place the new drier in position. 11) Remove the plugs from the suction, discharge, and process pipes. 12) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG. 13) Use an electronic leak detector or soap bubbles to check for leaks.

  • Page 54: Removal And Replacement Of Hot Gas Valve Or Liquid Line Valve

    9) 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 model, see the rating label inside the icemaker. 10) Attach the expansion valve bulb to the suction line in the same location as the previous bulb.

  • Page 55: Removal And Replacement Of Evaporator

    12) Replace the panels in their correct positions. 13) Turn on the power supply. E. Removal and Replacement of Evaporator CAUTION 1. Always install a new drier every time the sealed refrigeration system is opened. 2. Do not replace the drier until after all other repair or replacement has been made.

  • Page 56: Removal And Replacement Of Air-Cooled Condenser

    F. Removal and Replacement of Air-Cooled Condenser CAUTION 1. Always install a new drier every time the sealed refrigeration system is opened. 2. Do not replace the drier until after all other repair or replacement has been made. Install the new drier with the arrow on the drier in the direction of the refrigerant flow.
  • Page 57 3) Close the condenser water supply line shut-off valve. If connected to a closed loop water supply, also close the condenser return outlet shut-off valve. 4) Open the condenser water supply line drain valve. If connected to a closed loop water supply, also open the condenser return outlet drain valve.

  • Page 58: Removal And Replacement Of Water Regulating Valve (Water-Cooled Model)

    H. Removal and Replacement of Water Regulating Valve (water-cooled model) CAUTION 1. Always install a new drier every time the sealed refrigeration system is opened. 2. Do not replace the drier until after all other repair or replacement has been made.

  • Page 59: Adjustment Of Water Regulating Valve (Water-Cooled Model)

    19) Replace the panels in their correct positions. 20) Turn on the power supply. I. Adjustment of Water Regulating Valve (water-cooled model) 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.

  • Page 60: Removal And Replacement Of Thermistor

    J. Removal and Replacement of Thermistor This section covers removal and replacement of the thermistor. For a thermistor check procedure, see "IV.E. Thermistor Check." CAUTION 1. The thermistor is fragile; handle very carefully. 2. Always use the recommended sealant (high thermal conductive type), Model KE4560RTV manufactured by SHINETSU SILICONE, Part Code 60Y000-11, or Part Code 4A0683-01 or equivalent.

  • Page 61: Removal And Replacement Of Fan Motor (Air-Cooled And Remote Air-Cooled Models)

    K. Removal and Replacement of Fan Motor (air-cooled and remote air-cooled models) 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 junction box cover from the remote condenser unit (remote air-cooled model).

  • Page 62: Removal And Replacement Of Pump Motor

    M. Removal and Replacement of Pump Motor 1) Turn off the power supply. 2) Remove the front panel 3) Disconnect the discharge hose and the drain valve drain hose. See Fig. 13. 4) Disconnect the pump motor connector from the side of the control box. 5) Remove the thumbscrew securing the pump motor to the top of the assembly.

  • Page 63: Cleaning And Maintenance

    1. Cleaning Procedure 1) Dilute 9.5 fl. oz. (281 ml) of Hoshizaki "Scale Away" with 1.8 gal. (6.8 l) of warm water. 2) Remove all ice from the evaporator and the dispenser unit/storage bin. Note: To remove cubes on the evaporator, turn off the power supply and turn it on after 3 minutes.
  • Page 64 8) In bad or severe water conditions, clean the float switch as described below. Otherwise, continue to step 9. a. Remove the 2 thumbscrews securing insulation panel (B), then remove insulation panel (B). See Fig. 14. b. Disconnect the discharge hose, the drain valve drain hose, and the overflow drain hose.

  • Page 65: Sanitizing Procedure - Following Cleaning Procedure

    17) Turn off the power supply, then remove the front panel. 18) Move the control switch to the "ICE" position. 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.

  • Page 66: Maintenance

    15) Replace the front panel in its correct position. 16) Clean the dispenser unit/storage bin liner using a neutral cleaner. Rinse thoroughly after cleaning. 17) Turn on the power supply to start the automatic icemaking process. B. Maintenance This icemaker must be maintained individually, referring to the instruction manual and labels provided with the icemaker.

  • Page 67: Preparing The Icemaker For Long Storage

    C. Preparing the Icemaker for Long Storage CAUTION 1. When storing the icemaker for an extended time or in sub-freezing temperatures, follow the instructions below to prevent damage. 2. To prevent damage to the water pump, do not leave the control switch in the "SERVICE"...
  • Page 68 3) Open the condenser water supply line drain valve. If connected to a closed loop system, also open the condenser return line drain valve. 4) Attach a compressed air or carbon dioxide supply to the condenser water supply line drain valve. 5) Open the water regulating valve by using a screwdriver to pry up on the spring retainer underneath the spring.

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