Hoshizaki KML-351MAH Service Manual
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Hoshizaki KML-351MAH Service Manual

Low-profile modular crescent cuber
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Hoshizaki
Hoshizaki America, Inc.
"A Superior Degree
of Reliability"
www.hoshizaki.com
Low-Profile Modular Crescent Cuber
Models
KML-351MAH
KML-351MWH
SERVICE MANUAL
™
Number: 73149
Issued: 6-10-2008

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Summary of Contents for Hoshizaki KML-351MAH

  • Page 1 Hoshizaki Hoshizaki America, Inc. Low-Profile Modular Crescent Cuber Models KML-351MAH KML-351MWH SERVICE MANUAL “A Superior Degree of Reliability” www.hoshizaki.com ™ Number: 73149 Issued: 6-10-2008...
  • 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

    I. Specifications ........................6 A. Icemaker ........................6 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) ............ 6 1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later) ........7 2. KML-351MWH (water-cooled) .................. 8 II. General Information ......................9 A. Construction ........................9 1a.
  • Page 4 B. Wiring Diagrams ......................26 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) and KML-351MWH (water-cooled) (all auxiliary codes) ..........26 1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later) ........27 C. Performance Data ....................... 28 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) ..........28 1b.
  • Page 5 VI. Cleaning and Maintenance Instructions ................. 52 A. Cleaning and Sanitizing Procedures ................52 1. Cleaning Procedure ....................52 2. Sanitizing Procedure – Following Cleaning Procedure .......... 53 B. Maintenance ........................ 54 C. Preparing the Icemaker for Long Storage ..............54...

  • Page 6: Specifications

    I. Specifications A. Icemaker 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 8.8 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP.

  • Page 7: 1B. Kml-351Mah (Air-Cooled) (Auxiliary Codes: T-0 And Later)

    1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later) AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 13.2 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR.

  • Page 8: Kml-351Mwh (Water-Cooled)

    2. KML-351MWH (water-cooled) AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 7.5 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A APPROXIMATE ICE PRODUCTION Ambient WATER TEMP. (°F) PER 24 HR. Temp.(°F) lbs./day ( kg/day ) *345 (156) 340 (154)

  • Page 9: General Information

    II. General Information A. Construction 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) Water Supply Condenser Inlet Fan Motor Spray Tubes Drain Valve Wash Valve Junction Box Inlet Water Valve Condenser Control Box Drier Water Pump Liquid Line Valve Float Switch Control...

  • Page 10: 1B. Kml-351Mah (Air-Cooled) (Auxiliary Codes: T-0 And Later)

    1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later) Water Supply Condenser Inlet Fan Motor Spray Tubes Drain Valve Wash Valve Junction Box Inlet Water Valve Condenser Control Box Water Pump Expansion Drier Valve Control Switches Float Switch Hot Gas Valve...

  • Page 11: Kml-351Mwh (Water-Cooled)

    2. KML-351MWH (water-cooled) Water Supply Inlet Water Spray Tubes Regulator Drain Valve Wash Valve Junction Box Inlet Water Valve Condenser Control Box Water Pump Drier Liquid Line Float Switch Hot Gas Valve Valve Expansion Control Compressor Valve Switches Auxiliary Code S-0 Auxiliary Codes T-0 and later Bin Control...

  • Page 12: Sequence Of Operation

    B. Sequence of Operation The steps in the sequence are as outlined below. When power is supplied, the red "POWER OK" LED on the control board comes on. A 5 second delay occurs at startup. Note that the order of the LEDs from the outer edge of the control board is 1, 4, 3, 2. 1.

  • Page 13: Normal Harvest Cycle

    5. Normal Harvest Cycle LEDs 1, 4, and 2 are on. Comp and FMR remain energized, FMS de-energizes and HGV and WV energize. The control board monitors the warming of the evaporator via the thermistor located on the suction line. When the thermistor reaches 48°F (9°C), the control board reads a 3.9 kΩ...

  • Page 15: Control Board

    C. Control Board • A Hoshizaki exclusive solid-state control is employed in KML-351MAH and KML-351MWH Modular Crescent Cubers. • All models are pretested and factory-adjusted. CAUTION 1. Fragile, handle very carefully. 2. The control board contains integrated circuits, which are susceptible to failure due to static discharge.

  • Page 16: Control Board Layout

    1. Control Board Layout Control Products "E" Control Board "OUTPUT TEST" Switch (used to test relays on board) "ALARM RESET" Switch Dip Switch Freeze Timer LED Connector K3 Harvest Control (thermistor) Harvest Backup Connector K4 Timer LED Open (not connected) Alarm Buzzer Microprocessor Power LED...

  • Page 17: Features

    2. Features a) Maximum Water Supply Period – 6 minutes The inlet water valve will be open during harvest for 6 minutes or the length of harvest whichever is shorter. b) Harvest Backup Timer and Freeze Timer The harvest backup timer shuts down the icemaker if, for two cycles in a row, the harvest cycle takes more than 20 minutes to complete.

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

    f) LED Lights and Audible Alarm Safeties The red LED indicates proper control voltage and will remain on unless a control voltage problem occurs. At startup, a 5 second delay occurs while the control board conducts an internal timer check. A beep occurs when the power is turned off. The green LEDs 1 through 4 energize and sequence from initial startup as listed in the table below.

  • Page 19: Controls And Adjustments

    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 will decrease 24 hour production.

  • Page 20: C) Pump-Out Timer (Dip Switch 3 & 4)

    c) Pump-Out Timer (dip switch 3 & 4) When a freeze cycle is completed, the pump motor stops, and the icemaker resumes operation in 2 seconds. Then, during cycles when a pump out is called for, the pump motor drains the water tank for the time determined by the pump-out timer. The pump-out timer also acts in place of the harvest timer during cycles with a pump out.

  • Page 21: F) Freeze Timer (Dip Switch 9 & 10)

    f) Freeze Timer (dip switch 9 & 10) CAUTION Adjust to proper specification, or the unit may not operate correctly. The freeze timer setting determines the maximum allowed freeze time to prevent possible freeze-up issues. Upon termination of freeze timer, the control board initiates the harvest cycle.

  • Page 22: Harvest Control - Thermistor

    D. Harvest Control – Thermistor A thermistor (semiconductor) is used as a harvest control sensor. The resistance varies depending on the suction line temperature. The thermistor detects the temperature of the evaporator outlet to start the harvest 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 23: A) Drain

    a) DRAIN The KML series utilizes a pump-out drain system. When the service switch is active and in the "DRAIN" position, power is supplied to the pump and drain valve. b) CIRCULATE When the service switch is active and in the "CIRCULATE" position, power is supplied to the pump only.

  • Page 24: Technical Information

    III. Technical Information A. Water Circuit and Refrigeration Circuit 1. KML-351MAH (air-cooled) Condenser High Pressure Spray Tubes Evaporator Switch Inlet Water Valve Water Supply Wash Valve Drier Drain Valve Insulation Tube Heat Thermistor Exchanger Suction Hot Gas Line Valve Compressor...

  • Page 25: Kml-351Mwh (Water-Cooled)

    2. KML-351MWH (water-cooled) Water Regulating Valve Condenser Drain Inlet Water Valve Spray Tubes Evaporator Water Supply Water Supply Drier Wash Valve High Pressure Drain Valve Switch Insulation Tube Thermistor Heat Exchanger Suction Hot Gas Line Valve Compressor Pump Motor Float Access Switch Valve...

  • Page 26: Wiring Diagrams

    B. Wiring Diagrams 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) and KML-351MWH (water-cooled) (all auxiliary codes)

  • Page 27: 1B. Kml-351Mah (Air-Cooled) (Auxiliary Codes: T-0 And Later)

    1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later)

  • Page 28: Performance Data

    C. Performance Data 1a. KML-351MAH (air-cooled) (auxiliary code: S-0) 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 0.43...

  • Page 29: 1B. Kml-351Mah (Air-Cooled) (Auxiliary Codes: T-0 And Later)

    1b. KML-351MAH (air-cooled) (auxiliary codes: T-0 and later) 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 1000 APPROXIMATE WATER 70/21 0.64...

  • Page 30: Kml-351Mwh (Water-Cooled)

    2. KML-351MWH (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 1.50 1.61 2.69 CONSUMPTION PER 24 HR. 80/27 1.59 1.75...

  • Page 31: Service Diagnosis

    IV. Service Diagnosis A. 10-Minute Diagnostic Procedure The 10 minute check out procedure is basically a sequence check which can be used at unit start-up or for system diagnosis. Using this check out procedure will allow you to diagnose electrical system and component failures in approximately 10 minutes under normal operating conditions of 70°F (21°C) or warmer air and 50°F (10°C) or warmer water temperatures.
  • Page 32 5) Freeze Cycle – LED 1 is on. Compressor (and fan motor on a remote air-cooled unit) remains energized, pump motor, liquid line valve (if applicable), and fan motor (self-contained air-cooled unit) energize. The inlet water valve and hot gas valve de-energize.

  • Page 33: Diagnostic Charts

    B. 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 34 Problem Possible Cause Remedy [1] The icemaker will not i) Thermistor 1. Leads shorted or open 1. See "II.D. Harvest Control start. (continued) and high temperature – Thermistor." or harvest backup timer safety operates. (1 beep or 2 beep alarm) j) Hot Gas Valve 1.
  • Page 35 Problem Possible Cause Remedy [3] Compressor will e) Compressor 1. Power supply not 1. Refer to nameplate and not start or stops within specifications. correct. operating. (continued) 2. Wiring to compressor. 2. Check for loose connection or open, and replace. 3.

  • Page 36: Evaporator Is Frozen Up

    Problem Possible Cause Remedy [8] All components a) Refrigerant 1. Low charge. 1. Check for leaks. Recover, run, but no ice is repair, evacuate, and produced. recharge. 2. Air or moisture 2. Replace drier, evacuate, trapped. and recharge. b) Compressor 1.
  • Page 37 Problem Possible Cause Remedy [2]All ice formed on a) Evaporator 1. Scaled up. 1. Clean. evaporator does not 2. Damaged. 2. Replace. fall into bin in harvest b) Ambient and/or Water 1. Too cool. 1. Increase temperature. cycle. Temperature c) Water Supply Line 1.

  • Page 38: Low Ice Production

    3. Low Ice Production Problem Possible Cause Remedy [1] Freeze cycle time is a) Inlet Water Valve 1. Diaphragm does not 1. Check for water leaks with long. close. icemaker off. b) Float Switch 1. Float switch does not 1. Clean or replace. move freely.

  • Page 39: Abnormal Ice

    Problem Possible Cause Remedy [2] Harvest cycle time is d) Inlet Water Valve 1. Clogged. 1. Clean or replace. long. (continued) e) Evaporator 1. Scaled up. 1. Clean. 2. Damaged. 2. Replaced. f) Hot Gas Valve 1. Does not open, or 1.

  • Page 40: Other

    5. Other Problem Possible Cause Remedy [1] Icemaker will not stop a) Bin Control Thermostat 1. Set too cold. 1. See "II.E. Bin Control." when bin is filled with 2. Defective. 2. Replace. ice. [2] Abnormal noise. a) Pump Motor 1.

  • Page 41: Removal And Replacement Of Components

    V. Removal and Replacement of Components IMPORTANT 1. Ensure all components, fasteners, and thumbscrews are securely in place after the equipment is serviced. 2. 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 42: Evacuation And Recharge (R-404A)

    For air-cooled and water-cooled models, see the nameplate for the required refrigerant charge. For remote air-cooled models, 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 43: Removal And Replacement Of Compressor

    B. Removal and Replacement of Compressor IMPORTANT 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 44: Removal And Replacement Of Expansion Valve

    C. Removal and Replacement of Expansion Valve IMPORTANT Sometimes moisture in the refrigeration circuit exceeds the drier capacity and freezes up at the expansion valve. 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.

  • Page 45: Removal And Replacement Of Hot Gas Valve Or Liquid Line Valve

    D. Removal and Replacement of Hot Gas Valve or Liquid Line Valve IMPORTANT 1. Always use a copper tube of the same diameter and length when replacing the valve lines; otherwise, performance may be affected. Always install a new drier every time the sealed refrigeration system is opened.

  • Page 46: Removal And Replacement Of Evaporator

    E. Removal and Replacement of Evaporator IMPORTANT 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 front and top insulation.

  • Page 47: Removal And Replacement Of Water-Cooled Condenser

    5) Remove the corner barrier from the condenser. 6) Remove the screws securing the condenser assembly, then remove the assembly. 7) Install the new condenser. Attach the corner barrier to the new condenser. 8) Remove the drier, then place the new drier in position. 9) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.

  • Page 48: Removal And Replacement Of Water Regulating Valve - Water-Cooled Model Only

    12) Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of refrigerant to the system (if using an electronic leak detector), and then raise the pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with pressurized air for leak testing.

  • Page 49: Adjustment Of Water Regulating Valve - Water-Cooled Model Only

    14) Evacuate the system, and charge it with refrigerant. See the nameplate for the required refrigerant charge. 15) Connect the flare-connections. 16) Close the condenser water supply line drain valve, then open the condenser water supply line shut-off valve. 17) Check for water leaks. 18) Replace the panels in their correct positions.

  • Page 50: Removal And Replacement Of Thermistor

    J. Removal and Replacement of Thermistor IMPORTANT 1. 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. 3. Always use the recommended foam insulation (non-absorbent type) or equivalent.

  • Page 51: Removal And Replacement Of Water Valves

    3) Remove the junction box cover from the remote condenser unit (remote air-cooled model). 4) Disconnect the fan motor wires. 5) Remove the fan motor bracket and fan motor. 6) Install the new fan motor, connect the fan motor wires, and replace the removed parts in the reverse order of which they were removed.

  • Page 52: Cleaning And Maintenance Instructions

    1. Cleaning Procedure 1) Dilute approximately 10.5 fl. oz. (310 ml) of Hoshizaki "Scale Away" with 2 gallons (7.6 l) of warm water. 2) Remove all ice from the evaporator and the storage bin.

  • Page 53: Sanitizing Procedure - Following Cleaning Procedure

    15) Move the service switch to the "DRAIN" position. 16) Replace the front panel in its correct position and turn on the power supply for 2 minutes. 17) Turn off the power supply and remove the front panel. 18) Move the control switch to the "ICE" position. 19) Replace the front panel in its correct position.

  • Page 54: Maintenance

    12) Remove the front panel. 13) Repeat steps 18 through 31 in "1. Cleaning Procedure" two times to rinse thoroughly. 14) Move the control switch to the "ICE" position. 15) Replace the front panel in its correct position. 16) Clean the storage bin with water. 17) Turn on the power supply, and start the automatic icemaking process.
  • Page 55 1. On water-cooled model only, first remove the water from the water-cooled condenser: 1) Turn off the power supply and remove the front panel and right side panel. 2) Close the condenser water supply line shut-off valve. 3) Open the condenser water supply line drain valve. 4) Attach a compressed air or carbon dioxide supply to the condenser water supply line drain valve.
  • Page 56 ON OFF OFF ON OFF KML-250MWH B-1 and Later OFF OFF OFF ON ON OFF OFF OFF ON KML-351MAH V-1 and Later OFF OFF OFF OFF OFF OFF ON OFF OFF ON KML-351MWH ON OFF ON ON OFF OFF OFF OFF OFF ON...
  • Page 57 B. Wiring Diagram 1. KML-351MAH V-1 and Later...
  • Page 58 2. KML-351MWH TBD and Later Awaiting Data...

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