Hoshizaki KM-900MAF Service Manual
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Hoshizaki KM-900MAF Service Manual

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See also: Instruction Manual
NO.:
73083
ISSUED:
MAR. 19, 1999
REVISED:
DEC. 15, 2003
HOSHIZAKI
MODULAR CRESCENT CUBER
MODELS
KM-900MAF
KM-900MWF
KM-900MRF
KM-900MRF3
SERVICE MANUAL

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Summary of Contents for Hoshizaki KM-900MAF

  • Page 1 NO.: 73083 ISSUED: MAR. 19, 1999 REVISED: DEC. 15, 2003 HOSHIZAKI MODULAR CRESCENT CUBER MODELS KM-900MAF KM-900MWF KM-900MRF KM-900MRF3 SERVICE MANUAL...
  • 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

    This manual should be made available to the technician prior to service or maintenance. I. SPECIFICATIONS ... 5 1. KM-900MAF (Air-cooled) ... 5 2. KM-900MWF (Water-cooled) ... 6 3. KM-900MRF (Remote air-cooled) ... 7 4. KM-900MRE3 (Remote air-cooled 3 phase) ... 8 5.
  • Page 4 IV. SERVICE DIAGNOSIS ... 40 1. NO ICE PRODUCTION... 40 2. EVAPORATOR IS FROZEN UP ... 43 3. LOW ICE PRODUCTION ... 43 4. ABNORMAL ICE ... 44 5. OTHERS ... 44 V. REMOVAL AND REPLACEMENT OF COMPONENTS ... 45 1.

  • Page 5: Specifications

    I. SPECIFICATIONS 1. KM-900MAF * We reserve the right to make changes in specifications and design without prior notice.

  • Page 6: Km-900Mwf (Water-Cooled)

    2. KM-900MWF * We reserve the right to make changes in specifications and design without prior notice.

  • Page 7: Km-900Mrf (Remote Air-Cooled)

    3. KM-900MRF * We reserve the right to make changes in specifications and design without prior notice.

  • Page 8: Km-900Mre3 (Remote Air-Cooled 3 Phase)

    4. KM-900MRF3 * We reserve the right to make changes in specifications and design without prior notice.

  • Page 9: Condensing Unit, Urc-12F

    5. CONDENSING UNIT URC-12F...
  • Page 10 MODEL: URC-12F EXTERIOR DIMENSIONS (W x D x H) REFRIGERANT CHARGE URC-12F WEIGHT CONNECTIONS REFRIGERANT ELECTRICAL CONDENSER HEAD PRESSURE CONTROL AMBIENT CONDITION SPECIFICATIONS Galvanized Steel 35 - 11/16” x 15-11/16” x 21-15/16” (907.2 x 398 x 557.8 mm) R404A 4 lbs. 7 oz. (2000 g) Net 80 lbs.

  • Page 11: General Information

    II. GENERAL INFORMATION 1. CONSTRUCTION [a] KM-900MAF...
  • Page 12 [b] KM-900MWF...

  • Page 13: [C] Km-900Mrf (Remote Air-Cooled)

    [c] KM-900MRF...

  • Page 14: [D] Km-900Mrf3 (Remote Air-Cooled 3 Phase)

    [d] KM-900MRF3...

  • Page 15: [B] Km-900Mwf (Water-Cooled)

    2. CONTROLLER BOARD [a] SOLID-STATE CONTROL 1) A HOSHIZAKI exclusive solid-state control is employed in KM-900MAF, KM-900MWF, KM-900MRF and KM-900MRF3 Modular Crescent Cubers. 2) A Printed Circuit Board (hereafter called “Controller Board”) includes a stable and high quality control system.
  • Page 16 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 Evaporator 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 17 problem occurs. At startup a 5 second delay occurs while the board conducts an internal timer check. A short beep occurs when the power switch is turned ON or OFF. The green LED’s 1-4 represent the corresponding relays and energize and sequence 5 seconds from initial startup as follows: Sequence Step LED’s on Length:...
  • Page 18 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. The dip switches should be adjusted per the adjustment chart published in the Tech Specs book.

  • Page 19: [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 20 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 21 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 22: [D] Controls And Adjustments

    [d] CONTROLS AND ADJUSTMENTS The Dip Switch is factory-adjusted to the following positions: DIP SWITCH NO. KM-900MRF/3 OFF OFF KM-900MAF, OFF OFF KM-900MWF 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 23 1) Defrost Control A thermistor (Semiconductor) is used for a defrost control sensor. The resistance var- ies depending on the Suction Line temperatures. The Thermistor detects the tempera- ture 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 24 3) Drain Timer The Drain Timer is factory-adjusted, and no adjustment is required. SETTING Dip Switch No. 3 T1: Time to drain the Water Tank T2: Time to restrain defrost completion 4) Drain Counter Do not adjust the Drain Counter, or the Evaporator may freeze up. The Drain Counter is factory-adjusted to drain the Water Tank every 10 cycles, and no adjustment is required.

  • Page 25: [E] Checking Controller Board

    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 26 After the 1 minute ± 5 second water supply cycle and the 2 minute ± 10 second defrost cycle, the unit should start the freeze cycle. (ii) After the above step (i), disconnect the Float Switch leads from the Controller Board within the first 5 minutes of the freeze cycle.

  • Page 27: Technical Information

    III. TECHNICAL INFORMATION 1. WATER CIRCUIT AND REFRIGERANT CIRCUIT [a] KM-900MAF...

  • Page 28: [B] Km-900Mwf (Water-Cooled)

    [b] KM-900MWF...

  • Page 29: And Km-900Mrf3 (Remote Air-Cooled 3 Phase)

    [c] KM-900MRF and KM-900MRF3...

  • Page 30: Wiring Diagrams

    2. WIRING DIAGRAMS [a] KM-900MAF Note: Pressure Switch Cut-out 412 ± Cut-in 327 ± 21 PSIG PSIG...

  • Page 31: [B] Km-900Mwf (Water-Cooled)

    [b] KM-900MWF Note: Pressure Switch Cut-out 412 ± Cut-in 327 ± 21 PSIG PSIG...

  • Page 32: [C] Km-900Mrf (Remote Air-Cooled)

    [c] KM-900MRF Note: Pressure Switch Cut-out 412 ± Cut-in 327 ± 21 PSIG PSIG...

  • Page 33: [D] Km-900Mrf3 (Remote Air-Cooled 3 Phase)

    [d] KM-900MRF3 Note: Pressure Switch Cut-out 412 ± Cut-in 327 ± 21 PSIG PSIG...

  • Page 34: Timing Chart

    3. TIMING CHART When Control Sw. is turned OFF, Pressure Sw. is OFF, or Thermistor Temp. exceeds t1. Control Sw. in Thermo- stat ON Pressure Sw. ON Overheat Protect Reset (KM-1200SAE50) (KM-SRE50 *Note: The icemaker does not complete a defrost cycle in the first 2 or 3 minutes. See “II. 2. [d] CONTROLS AND ADJUSTMENTS.”...
  • Page 35 To Stand-by Cycle (When Control Sw. is turned OFF, Pressure Sw. is OFF, or Thermistor Temp. exceeds t1.) To Freeze Cycle From Freeze Cycle Min. 3 min (KM-1200SAE50) (KM-1200SRE50) The Pump Motor waits for 2 seconds before starting a drain cycle. See “II. 2. [d] CONTROLS AND ADJUSTMENTS.”...

  • Page 36: Performance Data

    4. PERFORMANCE DATA [a] KM-900MAF 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 37: [B] Km-900Mwf (Water-Cooled)

    [b] KM-900MWF 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 38: [C] Km-900Mrf (Remote Air-Cooled)

    [c] KM-900MRF 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 39: [D] Km-900Mrf3 (Remote Air-Cooled 3 Phase)

    [b] KM-900MRF3 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 40: Service Diagnosis

    IV. 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 e) High Pressure Control f) Transformer g) Wiring to Controller Board h) Thermistor i) Hot Gas Solenoid...
  • Page 41 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 will not start or operates b) High Pressure intermittently.
  • Page 42 PROBLEM [4] Water a) Water Solenoid continues to Valve be supplied in b) Controller Board freeze cycle. [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.

  • Page 43: 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 44: Abnormal Ice

    4. ABNORMAL ICE PROBLEM [1] Small Cube a) Ice Cube Guide b) See chart 1 - [5], and check water supply line, Water Solenoid Valve, water system, Pump Motor or Controller Board. c) Drain Valve [2] Cloudy or a) See chart 2 - [1] and - [3], and check Float Switch, Water Solenoid Valve, irregular cube Controller Board, Spray Tubes, water system, refrigerant charge or Expansion Valve.

  • Page 45: 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 46: 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 refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.

  • Page 47: 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 48 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 49: 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 50: 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 51 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 52: 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 53: 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 54: 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 55: Removal And Replacement Of Condensing Pressure

    10. REMOVAL AND REPLACEMENT OF CONDENSING PRESSURE REGULATOR (C.P.R.) - REMOTE AIR-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 56: Removal And Replacement Of Thermistor

    11. 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 57: Removal And Replacement Of Fan Motor

    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. Note: Do not cut the leads of the Thermistor while installing it. 12) Replace the Control Box Cover and the panels in their correct positions.

  • Page 58: Removal And Replacement Of Water Valve

    13. REMOVAL AND REPLACEMENT OF WATER VALVE 1) Turn off the power supply. 2) Close the Water Supply Line Shut-off Valve. 3) Remove the Front Panel. 4) Remove the Valve Outlet Tubing by releasing the Clamp. 5) Remove the Bracket from the unit. 6) Remove the Fitting Nut and Water Valve.

  • Page 59: Removal And Replacement Of Spray Tubes

    8) Remove the closed end connectors from the Pump Motor leads. 9) Remove the two screws and the Pump Motor Bracket. 10) Remove the Pump Housing, and check the Impeller. 11) If the Impeller is defective, install a new Impeller. 12) Install the new motor or new parts, and replace the removed parts in the reverse order of which they were removed.

  • Page 60: Maintenance And Cleaning Instructions

    VI. MAINTENANCE AND CLEANING 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 61 [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” position. 3) Wait 3 minutes. 4) Close the Potable Water Supply Line Shut-off Valve and open the Potable Water Supply Line Drain Valve.

  • Page 62: 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 conditions.

  • Page 63: [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 gallons 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 64: [B] Sanitizing Procedure

    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 Switchto the “Wash” position. 24) Replace the Front Panel in its correct position.

  • Page 65: Maintenance

    8) Drain the Water Tank. See the above step 5) in “[a] CLEANING PROCEDURE.” 9) Replace the removed parts and the Insulation Panel in their correct positions. 10) Repeat the above steps 15) through 28) in “[a] CLEANING PROCEDURE” two times to rinse thoroughly.

This manual is also suitable for:

Km-900mrfKm-900mrf3Km-900mwf

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