Hoshizaki KMD-705MAJ Service Manual
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Hoshizaki KMD-705MAJ Service Manual

Hoshizaki KMD-705MAJ Service Manual

Modular crescent cuber
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Service Manual
Modular Crescent Cuber
Models
KMD-505MAJ, MWJ, MRJZ
KMD-705MAJ, MWJ, MRJZ
hoshizakiamerica.com
Number: 73252
Issued: 4-30-2024

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Summary of Contents for Hoshizaki KMD-705MAJ

  • Page 1 Service Manual Modular Crescent Cuber Models KMD-505MAJ, MWJ, MRJZ KMD-705MAJ, MWJ, MRJZ Number: 73252 hoshizakiamerica.com Issued: 4-30-2024...
  • Page 2 WARNING Only qualified service technicians should install and service the appliance. To obtain the name and phone number of your local Hoshizaki Certified Service Representative, visit www.hoshizakiamerica.com. No service should be undertaken until the technician has thoroughly read this Service Manual. Failure to service and maintain the appliance in accordance with this manual will adversely affect safety, performance, component life, and warranty coverage.

  • Page 3: Table Of Contents

    IMPORTANT This manual should be read carefully before the appliance is serviced. Read the warnings and guidelines contained in this manual carefully as they provide essential information for the continued safe use, service, and maintenance of the appliance. Retain this manual for any further reference that may be necessary. CONTENTS Important Safety Information ....................
  • Page 4 A. Specification and Performance Data Sheets ............... 54 1. KMD-505MAJ ......................54 2. KMD-505MWJ ....................... 55 3. KMD-505MRJZ with URC-5FZ ................56 4. KMD-705MAJ ......................57 5. KMD-705MWJ ....................... 58 6. KMD-705MRJZ with URC-9FZ ................59 B. Wiring Diagram ......................60...

  • Page 5: Important Safety Information

    Important Safety Information Throughout this manual, notices appear to bring your attention to situations which could result in death, serious injury, damage to the appliance, or damage to property. WARNING Indicates a hazardous situation which could result in death or serious injury.
  • Page 6 WARNING, continued • Children should be properly supervised around this appliance. • Do not climb, stand, or hang on the appliance or allow children or animals to do so. Serious injury could occur or the appliance could be damaged. • Do not use combustible spray or place volatile or flammable substances near the appliance.

  • Page 7: Construction And Water/Refrigeration Circuit Diagrams

    I. Construction and Water/Refrigeration Circuit Diagrams A. Construction 1. Air-Cooled Models (MAJ) Drain Valve Cleaning Valve Water Supply Inlet Spray Tube Evaporator Inlet Water Valve Condenser Fan Motor Thermostatic Expansion Valve Cube Guide High-Pressure Switch Strainer Water Pump Ultrasonic Bin Control Sensor Float Switch Drier...

  • Page 8: Water-Cooled Models (Mwj)

    2. Water-Cooled Models (MWJ) Drain Valve Cleaning Valve Water Supply Inlet Spray Tube Evaporator Water Regulating Inlet Water Valve Valve Thermostatic Condenser Expansion Valve Cube Guide High-Pressure Switch Strainer Water Pump Ultrasonic Bin Control Sensor Float Switch Drier Compressor Liquid Line Valve Hot Gas Valve Model Shown: KMD-505MWJ...

  • Page 9: Remote Models (Mrjz )

    3. Remote Models (MRJZ ) Drain Valve Water Supply Inlet Cleaning Valve Spray Tube Evaporator Liquid Line Shut Off Valve Inlet Water Valve Discharge Shut Off Valve Thermostatic Expansion Valve High-Pressure Cube Guide Switch Receiver Tank Strainer Water Pump Ultrasonic Bin Control Float Switch Sensor...

  • Page 10: Water/Refrigeration Circuit Diagrams

    B. Water/Refrigeration Circuit Diagrams 1. Air-Cooled Models (MAJ)

  • Page 11: Water-Cooled Models (Mwj)

    2. Water-Cooled Models (MWJ)

  • Page 12: Remote Models (Mrjz)

    3. Remote Models (MRJZ)

  • Page 13: Sequence Of Operation And Service Diagnosis

    II. Sequence of Operation and Service Diagnosis A. Sequence of Operation Flow Charts 1. Operation Flow Chart...

  • Page 14: Shutdown Flow Chart

    2. Shutdown Flow Chart...

  • Page 15: Service Diagnosis

    B. Service Diagnosis WARNING • The appliance should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. • Risk of electric shock. Control switch in "OFF" position does not de-energize all loads.
  • Page 16 a) Sequence and Component Diagnosis 3) Power On: Turn on the power supply, then move the control switch to the "ON" position and the mode switch to the "ICE" position. A 5-sec. delay occurs. CB red "POWER" LED turns on. If CB orange "BIN CLS" LED is on, see "II.D.1.
  • Page 17 4) 1-Min. Fill Cycle – WV LED is on. WV energizes. After 1 min., CB checks for a closed FS. If FS is closed, the harvest cycle begins. If harvest cycle begins (Comp, HGV, FMR energized), continue to step 5a. If FS is open, fill cycle continues until FS closes (low water safety protection during initial start up and at the end of each harvest).
  • Page 18 5b) Harvest Pump Time (Harvest Assist) – Comp, PM, and FM/HGV LEDs are on. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2 and S5 dip switch 4).
  • Page 19 b) Comp and FMR Diagnosis: If Comp and FMR de-energize once freeze begins, check that appliance has not shut off on HPS (CB "POWER" LED off). If so, check "3)b) HPS Diagnosis" above. Comp Diagnosis: If CB "POWER" LED and Comp LED are on, check for 115VAC at CB K1 #9 (Y) to neutral (W).
  • Page 20 g) WRV Diagnosis: WRV is factory set and generally no adjustment is required. If WRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A. Specification and Performance Data Sheets." If refrigerant pressures are correct and WRV does not open, adjust or replace as needed. See "IV.C. Water Regulating Valve Adjustment (water-cooled model)."...
  • Page 21 Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above), after 5 min. of freeze disconnect CB black K5 connector (FS connector). Check that PM stops and re-starts. Next, check that PM and DV energized (water flowing down the drain through DV). If PM does not stop and re-start, check that CB Comp, PM, and DV LEDs are on.

  • Page 22: Control Board Check

    C. Control Board Check Before replacing CB 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 CB is in alarm (beeping), press the "ALARM RESET" button on CB while CB is beeping.
  • Page 23 4) To verify voltage output from CB to the components, slide the CB K1 connector out far enough to allow multimeter lead contact. With the icemaker in the cycle to be tested, check output voltage from the corresponding pin on CB K1 connector to a neutral (W) wire.

  • Page 24: Bin Control Check And Adjustment

    Note: It is strongly advised to keep a known "good" UBC sensor on your truck, for troubleshooting assistance. The ultrasonic bin control is factory set for use on Hoshizaki America standard ice storage bins. If mounted on a dispenser application or if a change to the ice level in an ice storage bin application is desired, see "II.D.2.
  • Page 25 4) Bin Empty Diagnosis: As water begins to fill the water tank (1-min. fill), place an object 5" to 7" (127 to 178 mm) away from the UBC lens. See Fig. 3. CB 5-sec. delay timer starts. "BIN CLS" LED turns on. CB 5-sec. delay timer terminates, CB 15-sec. delay timer starts.

  • Page 26: Ultrasonic Bin Control Adjustment

    • Failure to properly adjust the bin control setting could result in water leakage, ice backup, and icemaker damage. The ultrasonic bin control is factory set to 1 for use on Hoshizaki America standard ice storage bins. See the table below for adjustments to ice level.
  • Page 27 For Standard Ice Storage Bins, Hoshizaki DB and DM Dispenser Units, and Coca-Cola Freestyle Dispenser Units ® Application Bin Control Ice Level Settings Shutdown Distance From Bin Control Lens Bin Control Setting (Restart is 4 in. (102 mm) below shutdown distance) Standard Ice Storage Bins 304 mm (12")
  • Page 28 For Non-Hoshizaki Dispenser Units Bin Control Ice Level Settings Shutdown Distance From Bin Control Lens Bin Control Setting (Restart is 4 in. (102 mm) below shutdown distance) 304 mm (12") (Factory Default) Do not adjust dispensers to this setting. 335 mm (13") 416 mm (16 3/8")

  • Page 29: Float Switch Check And Cleaning

    E. Float Switch Check and Cleaning The FS is used to determine whether there is sufficient water in the water tank after the 1-min. fill cycle and after each harvest cycle. The FS is also used to determine that the appropriate volume of water has been converted into ice before switching out of the freeze cycle.
  • Page 30 Be careful not to bend the spring retainer clip excessively when removing it. See Fig. 8. 6) Wipe down the float switch bracket assembly, stem, and float with a mixture of 1 part Hoshizaki "Scale Away" and 25 parts warm water. Rinse the parts thoroughly with clean water.

  • Page 31: Thermistor Check

    F. Thermistor Check To check thermistor resistance, follow the steps below. 1) Turn off the power supply. 2) Remove the front panel. Move the control switch to the "OFF" position, then remove the top and right side panels. 3) Remove the thermistor from the refrigerant tubing. 4) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 min.

  • Page 32: Diagnostic Tables

    I. Diagnostic Tables 1. No Ice Production No Ice Production - Possible Cause 1. Power Supply a) Off, blown fuse, or tripped breaker. b) Not within specifications. 2. Fuse (Control Box) a) Blown. 3. Control Switch a) In "OFF" or "PUMP" position. b) Defective.
  • Page 33 2. Freeze-Up Defrost and clean the icemaker prior to diagnosing freeze-up. Fill out a freeze-up checklist. See "II.J. Freeze Up Check List," the Hoshizaki America Technician's Pocket Guide, or contact your local distributor for a copy of the freeze-up checklist.
  • Page 34 Freeze-Up - Possible Cause 10. Thermistor a) Loose, disconnected, or defective. See "II.F. Thermistor Check" 11. Thermostatic Expansion Valve a) Defective. 12. Hot Gas Valve a) Defective. 13. Liquid Line Valve a) Defective. Freeze Cycle 1. Evaporator a) Scaled up. b) Damaged.
  • Page 35 Low Ice Production - Possible Cause Long Freeze Cycle 1. Evaporator a) Scaled up, dirty. 2. Float Switch a) Scaled up, dirty. See "II.E. Float Switch Check b) Float sticking. and Cleaning" c) Defective switch. 3. Inlet Water Valve a) Leaking by. 4.

  • Page 36: Freeze-Up Check List

    J. Freeze-Up Check List Freeze-Up Check List Please Complete When Diagnosing a Freeze-Up, Refrigerant Leak, or Low Charge Technical Support Fax #: 770-487-3360 Make Copies And Use As Needed Model #___________________________ Serial # ______________________Install Date__________Freeze-Up Date___________ List model and manufacture of bin or dispenser__________________________. Date appliance was last cleaned:__________.

  • Page 37: Controls And Adjustments

    III. Controls and Adjustments • A Hoshizaki exclusive control board is employed in KM series appliances. • All models are pretested and factory adjusted. • For a control board check procedure, see "II.C. Control Board Check." NOTICE • Fragile, handle very carefully.

  • Page 38: Control Board Layout

    A. Control Board Layout Control Board • Ultrasonic Bin Control • "ALARM RESET" Button (white) Distance Adjustment • S4 Dip Switch • S5 Dip Switch • "OUTPUT TEST" • K12 (white) Connector (5VDC) Button Ultrasonic Bin Control (used to test relays on control board) •...

  • Page 39: Led Lights And Audible Alarm Safeties

    B. LED Lights and Audible Alarm Safeties An audible beep occurs and red CB "POWER" LED turns on when control switch is moved to "ICE" position. Sequence Green LEDs turn on and sequence from initial startup as listed in the table below. Order of green LEDs from the outer edge of control board is Comp, CV, WV, DV, PM, FM/HGV.

  • Page 40: Settings And Adjustments

    The dip switches are factory-adjusted to the following positions: S4 Dip Switch No. KMD-505MAJ, KMD-505MWJ, KMD-505MRJZ OFF OFF OFF OFF OFF OFF ON OFF OFF OFF KMD-705MAJ, KMD-705MWJ, KMD-705MRJZ OFF OFF OFF OFF OFF OFF ON OFF OFF OFF S5 Dip Switch (Do Not Adjust) Dip Switch No.

  • Page 41: Harvest Time (S4 Dip Switch 1 & 2)

    2. Harvest Time (S4 dip switch 1 & 2) The harvest timer starts counting when the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads 3.9 kΩ from the thermistor. The harvest timer is factory set, and generally no adjustment is required. However, a setting longer than the factory setting may be advised in cases where the drain provided at harvest needs to be prolonged for extra cleaning.

  • Page 42: Pump-Out Frequency Control (S4 Dip Switch 5)

    4. Pump-Out Frequency Control (S4 dip switch 5) The pump-out frequency control is factory set to drain the water tank every 10 cycles. Generally no adjustment is required. However, where water quality is bad and the icemaker needs a pump-out more often, the pump-out frequency can be adjusted. The pump-out frequency control can be set to have a pump-out occur every cycle, or every10 cycles.

  • Page 43: Harvest Pump Time (Harvest Assist (S4 Dip Switch 7))

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

  • Page 44: Float Switch Selector (S5 Dip Switch 1)

    9. Float Switch Selector (S5 dip switch 1) NOTICE Do not adjust. This must be left in the factory default position or the icemaker will not operate correctly. This dip switch setting allows use of this control board in single and dual float switch models.

  • Page 45: Anti-Slush (S5 Dip Switch 5)

    12. Anti-Slush (S5 dip switch 5) This dip switch setting provides anti-slush control during the freeze cycle. When the evaporator temperature reaches 36°F (2.2°C) the control board reads a 5.8 kΩ signal from the thermistor and de-energizes the water pump for 10 sec. to prevent slush from blocking the water supply tubing, causing irregular freeze patterns.

  • Page 46: Refrigeration Circuit And Component Service Information

    IV. Refrigeration Circuit and Component Service Information WARNING • This appliance should be diagnosed and repaired only by qualified service personnel to reduce the risk of death, electric shock, serious injury, or fire. • Move the control switch to the "OFF" position and turn off the power supply. Place the disconnect in the "OFF"...
  • Page 47 2. Brazing WARNING • R-404A itself is not flammable at atmospheric pressure and temperatures up to 176°F (80°C). • 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 48 Remember to loosen the connection and purge the air from the hose. For the required refrigerant charge, see the rating label inside the icemaker. Hoshizaki recommends only virgin refrigerant or reclaimed refrigerant which meets AHRI Standard 700 (latest edition) be used.

  • Page 49: Component Service Information

    B. Component Service Information NOTICE When replacing a component listed below, see the notes to help ensure proper operation. Component Notes Compressor 1 phase: Install a new start capacitor, run capacitor, and start relay. Thermostatic • Attach the thermostatic expansion valve bulb to the suction line in the same location as Expansion Valves the previous bulb.

  • Page 50: Maintenance

    V. Maintenance The maintenance schedule below is a guideline. More frequent maintenance may be required depending on water quality, the appliance's environment, and local sanitation regulations WARNING • Only qualified service technicians should service the appliance. • To reduce the risk of electric shock, do not touch the control switch or service switch with damp hands •...

  • Page 51: Preparing The Appliance For Periods Of Non-Use

    VI. Preparing the Appliance for Periods of Non-Use NOTICE • When storing the appliance for an extended time or in sub-freezing temperatures, follow the instructions below to prevent damage. • To prevent damage to the water pump, do not operate the appliance with the control switch in the "PUMP"...
  • Page 52 3. On water-cooled model, remove the water from the water-cooled condenser: 1) Make sure the power supply is off, then remove the front panel and right side panel. 2) Close the condenser water supply line shut-off valve. If connected to a closed loop system, also close the condenser return line shut-off valve.

  • Page 53: Disposal

    VII. Disposal The appliance contains refrigerant and must be disposed of in accordance with applicable national, state, and local codes and regulations. Refrigerant must be recovered by properly certified service personnel.

  • Page 54: Technical Information

    VIII. Technical Information We reserve the right to make changes in specifications and design without prior notice. A. Specification and Performance Data Sheets Pressure data is recorded at 5 min. into freezing cycle. The data not in bold should be used for reference only.

  • Page 55: Kmd-505Mwj

    2. KMD-505MWJ Model: KMD-505MWJ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 11.0 A ( 5 Min. Freeze AT 104°F / WT 100°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 960 (4.15) 950 (3.85) WATER gal./24HR (gal./100 lbs.)

  • Page 56: Kmd-505Mrjz With Urc-5Fz

    3. KMD-505MRJZ with URC-5FZ Model: KMD-505MRJZ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 12.4 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1160 (5.70)

  • Page 57: Kmd-705Maj

    4. KMD-705MAJ Model: KMD-705MAJ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 14.3 A ( 5 Min. Freeze AT 104°F / WT 100°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1230 (4.75)

  • Page 58: Kmd-705Mwj

    5. KMD-705MWJ Model: KMD-705MWJ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 13.0 A ( 5 Min. Freeze AT 104°F / WT 100°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1140 (3.80) 1120 (3.49) WATER gal./24HR (gal./100 lbs.)

  • Page 59: Kmd-705Mrjz With Urc-9Fz

    6. KMD-705MRJZ with URC-9FZ Model: KMD-705MRJZ Specification Sheet AC SUPPLY VOLTAGE 115/60/1 AMPERAGE 13.7 A ( 5 Min. Freeze AT 104°F / WT 80°F) MINIMUM CIRCUIT AMPACITY 20 A MAXIMUM FUSE SIZE 20 A ELECTRIC & WATER CONSUMPTION 90/70°F 70/50°F ELECTRIC W (kWH/100 lbs.) 1230 (4.40)

  • Page 60: Wiring Diagram

    B. Wiring Diagram...

This manual is also suitable for:

Kmd-505majKmd-705mwjKmd-505mrjzKmd-705mrjzKmd-505mwj

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