Hoshizaki KMD-270AWA Service Manual
  1. Manuals
  2. Brands
  3. Hoshizaki Manuals
  4. Ice Maker
  5. KMD-270AWA
  6. Service manual

Hoshizaki KMD-270AWA Service Manual

Modular crescent cuber
Hide thumbs Also See for KMD-270AWA:
Table of Contents

Advertisement

Quick Links

MODULAR CRESCENT CUBER
MODEL
HOSHIZAKI
KMD-270AA
KMD-270AWA
SERVICE MANUAL
NO.
F049-817
ISSUED: SEP. 30, 2010
REVISED: AUG. 10, 2011

Advertisement

Table of Contents
loading

Related Manuals for Hoshizaki KMD-270AWA

Summary of Contents for Hoshizaki KMD-270AWA

  • Page 1 NO. F049-817 ISSUED: SEP. 30, 2010 REVISED: AUG. 10, 2011 HOSHIZAKI MODULAR CRESCENT CUBER KMD-270AA MODEL KMD-270AWA SERVICE MANUAL...

  • Page 2: Table Of Contents

    I. SPECIFICATIONS--------------------------------------------------------------------------------------- 1 1. SPECIFICATIONS ----------------------------------------------------------------------------------- 1 [a] KMD-270AA (50Hz) (air-cooled) -------------------------------------------------------------- 1 [b] KMD-270AA (60Hz) (air-cooled) -------------------------------------------------------------- 2 [c] KMD-270AWA (50Hz) (water-cooled) ------------------------------------------------------- 3 [d] KMD-270AWA (60Hz) (water-cooled) ------------------------------------------------------- 4 II. GENERAL INFORMATION--------------------------------------------------------------------------- 5 1. CONSTRUCTION------------------------------------------------------------------------------------ 5 [a] KMD-270AA---------------------------------------------------------------------------------------- 5 [b] KMD-270AWA ------------------------------------------------------------------------------------- 6 2.
  • Page 3 IV. SERVICE DIAGNOSIS ------------------------------------------------------------------------------27 1. 10-MINUTE DIAGNOSTIC PROCEDURE -----------------------------------------------------27 2. DIAGNOSTIC CHARTS-----------------------------------------------------------------------------29 [a] NO ICE PRODUCTION ------------------------------------------------------------------------29 [b] EVAPORATOR IS FROZEN UP -------------------------------------------------------------32 [c] LOW ICE PRODUCTION ----------------------------------------------------------------------33 [d] ABNORMAL ICE---------------------------------------------------------------------------------33 [e] OTHER ---------------------------------------------------------------------------------------------34 V. REMOVAL AND REPLACEMENT-----------------------------------------------------------------35 1. SERVICE FOR REFRIGERANT LINES --------------------------------------------------------35 [a] SERVICE INFORMATION ---------------------------------------------------------------------35 [b] REFRIGERANT RECOVERY-----------------------------------------------------------------36 [c] EVACUATION AND RECHARGE------------------------------------------------------------36...

  • Page 4: Specifications

    I. SPECIFICATIONS 1. SPECIFICATIONS [a] KMD-270AA (50Hz) (air-cooled) AC SUPPLY VOLTAGE 1 PHASE 220-240 50Hz AMPERAGE 4.9A (AT. 32°C, WT. 21°C) STARTING AMPERAGE 24 A ELECTRICAL CONSUMPTION 1030W (AT. 32°C, WT. 21°C) POWER FACTOR 90 % POWER SUPPLY CAPACITY 1.67 kVA ( 7.3A ) Approx.

  • Page 5: [B] Kmd-270Aa (60Hz) (Air-Cooled)

    [b] KMD-270AA (60Hz) (air-cooled) AC SUPPLY VOLTAGE 1 PHASE 230 60Hz AMPERAGE 4.8A (AT. 32°C, WT. 21°C) STARTING AMPERAGE 26 A ELECTRICAL CONSUMPTION 1087W (AT. 32°C, WT. 21°C) POWER FACTOR 98 % POWER SUPPLY CAPACITY 2.00 kVA ( 8.7A ) Approx.

  • Page 6: [C] Kmd-270Awa (50Hz) (Water-Cooled)

    [c] KMD-270AWA (50Hz) (water-cooled) AC SUPPLY VOLTAGE 1 PHASE 220-240 50Hz AMPERAGE 4.6A (AT. 32°C, WT. 21°C) STARTING AMPERAGE 24 A ELECTRICAL CONSUMPTION 917W (AT. 32°C, WT. 21°C) POWER FACTOR 87 % POWER SUPPLY CAPACITY 1.52 kVA ( 6.6A ) Approx.

  • Page 7: [D] Kmd-270Awa (60Hz) (Water-Cooled)

    [d] KMD-270AWA (60Hz) (water-cooled) AC SUPPLY VOLTAGE 1 PHASE 230 60Hz AMPERAGE 4.7A (AT. 32°C, WT. 21°C) STARTING AMPERAGE 26 A ELECTRICAL CONSUMPTION 1075W (AT. 32°C, WT. 21°C) POWER FACTOR 98 % POWER SUPPLY CAPACITY 1.96 kVA ( 8.5A ) Approx.

  • Page 8: General Information

    II. GENERAL INFORMATION 1. CONSTRUCTION Water Supply Tube [a] KMD-270AA Drain Valve Water Supply Inlet Spray Guide Hot Gas Valve Spray Tube Access Valve (High Side) Condenser * Not provided for later production Thermistor Expansion Valve Access Valve (Low Side) Fan Motor Compressor Cube Guide...

  • Page 9: [B] Kmd-270Awa

    [b] KMD-270AWA Water Supply Tube Drain Valve Water Supply Inlet Spray Guide Hot Gas Valve Spray Tube Access Valve (High Side) Water Regulator * Not provided for later production Thermistor Expansion Valve Access Valve (Low Side) Condenser Compressor Cube Guide...

  • Page 10: Sequence Of Operation

    2. SEQUENCE OF OPERATION The steps in the sequence are as outlined below. When power is supplied, a 5 second delay occurs at startup. Note that the order of the LEDs from the outer edge of the board is 5, 6, 8, 9, 4, 7.

  • Page 11: [E] Normal Harvest Cycle

    [e] NORMAL HARVEST CYCLE LEDs 5, 6, and 8 are on. Comp continues to run, HGV remains open and HWV opens. As the evaporator warms, the thermistor reaches 9°C. The control board then receives the thermistor’s 3.9kΩ signal and starts the harvest timer. HWV is open during harvest for a maximum of 6 minutes or the length harvest minus 0, 10, 30, or 50 seconds (adjustable by S1 dip switch 7 &...

  • Page 13: Control Board

    3. CONTROL BOARD * A HOSHIZAKI exclusive solid-state control is employed in KMD-270AA and KMD-270AWA Crescent Cubers. * All models are pretested and factory-adjusted. 1. Fragile, handle very carefully. 2. A control board contains integrated circuits, which are susceptible to failure due to static discharge.

  • Page 14: [A] Control Board Layout

    [a] CONTROL BOARD LAYOUT #4 Harvest Water Valve #5 Freeze Water Valve #1, 2, 3 Float Switch P01771-02...

  • Page 15: [B] Features

    [b] FEATURES a) Maximum Water Supply Period - 6 minutes The harvest water valve will be open during harvest for 6 minutes or the length of harvest minus 0, 10, 30, or 50 seconds (adjustable by S dip switch 7 & 8), 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 16 f) LED Lights and Audible Alarm Safeties The control board includes LED indicator lights, audible alarm safeties, and an output test feature. The "POWER OK" LED indicates control voltage and will remain on unless a control voltage problem occurs. The “POWER OK” LED flashes continuously when the bin is full and DV energizes for a maximum of 5 minutes to drain the water tank.

  • Page 17: [C] Controls And Adjustments

    Default Dip Switch Settings The dip switch is factory-adjusted to the following positions: S1 Dip Switch No. KMD-270AA (50Hz) KMD-270AA (60Hz) KMD-270AWA (50Hz) KMD-270AWA (60Hz) S2 Dip Switch * Functions of S2 dip switch nos. 2 through 6 depend on program version.
  • Page 18 c) Drain Timer (S1 dip switch 3 & 4) Once every ten freeze cycles, the drain valve opens to drain the water tank for the time determined by the drain timer. These switches also determine the time to delay completion of a defrost cycle, i.e.
  • Page 19 Harvest Promotion Control No. 2 Activated Deactivated i) Refill Counter (S2 dip switch 3) Do not adjust. This must be left in the factory default position or the unit will not operate properly. The KMD-270AA and KMD-270AWA refill 1 time.
  • Page 20 j) Harvest Completion Detection Control (S2 dip switch 4) Do not adjust. This must be left in the factory default position or the unit will not operate properly. It is activated on the KMD-270 series. When activated, this control determines whether ice remains on the evaporator at the end of a harvest cycle and at the beginning of a freeze cycle.

  • Page 21: [D] Control Board Check Procedure

    S2 Dip Switch Setting Anti-Slush Control No. 6 Activated (Ver. 2.0) Deactivated m) Anti-Slush Control (S2 dip switch 6) [Program Ver. 3.2] Do not adjust. This must be left in the factory default position or the unit will not operate properly.

  • Page 22: Harvest Control - Thermistor

    4. HARVEST CONTROL – THERMISTOR A thermistor (semiconductor) is used as a harvest control sensor, anti-slush sensor, and overfreeze sensor. The resistance varies depending on the suction line temperatures. The thermistor detects the temperature of the evaporator outlet to start the harvest timer, to momentarily stop the pump motor during the freeze cycle, or to extend the harvest cycle time.

  • Page 23: Float Switch

    5. FLOAT SWITCH [a] EXPLANATION OF OPERATION The float operates 2 switches within the float switch. The lower switch (black and blue wires) is used for low water safety protection, initiating the freeze cycle refill and terminating the freeze cycle. The upper switch (black and red wires) is used to terminate the freeze cycle refill only.

  • Page 24: Bin Control

    6. BIN CONTROL This machine uses a lever-actuated proximity switch (mechanical bin control) to control the ice level in the storage bin. No adjustment is required. [a] EXPLANATION OF OPERATION The bin control is connected to the K1 connector (pins 4 & 5) on the control board. When the bin control is calling for ice (proximity switch closed;...

  • Page 25: Switches

    7. SWITCHES Two different control switches are used for operation of KMD-270AA and KMD-270AWA. These switches are referred to as the "control switch" and the "service switch" and are located on the control box. [a] CONTROL SWITCH This switch is used to place the machine into one of three modes: “OFF” (center position), “ICE”...

  • Page 26: Technical Information

    III. TECHNICAL INFORMATION 1. WATER CIRCUIT AND REFRIGERANT CIRCUIT...

  • Page 27: Wiring Diagram

    2. WIRING DIAGRAM [a] KMD-270AA, KMD-270AWA (50Hz)

  • Page 28: [B] Kmd-270Aa, Kmd-270Awa (60Hz)

    [b] KMD-270AA, KMD-270AWA (60Hz)

  • Page 29: Timing Chart

    3. TIMING CHART...

  • Page 30: Service Diagnosis

    IV. SERVICE DIAGNOSIS 1. 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 21°C or warmer air and 10°C or warmer water temperatures.
  • Page 31 a. Lower Float Switch 1st Activation: Refill – The refill can occur at any time during the freeze cycle (1 refill per cycle). As ice builds the water level drops in the reservoir and the lower float switch activates (opens). LED 5 comes on and the control board energizes the fill water valve.

  • Page 32: Diagnostic Charts

    2. DIAGNOSTIC CHARTS [a] NO ICE PRODUCTION 2. See "II. 6. [b] Bin Control Check Procedure." 5. See chart [a] [7].
  • Page 33 1. See "II. 4. Harvest Control - Thermistor." 1. See "II. 3. [d] Control Board Check Procedure." 1. See "II. 3. [d] Control Board Check Procedure."...
  • Page 34 1. See "II. 3. [d] Control Board Check Procedure." 1. See "II. 3. [d] Control Board Check Procedure." 1. See "II. 3. [d] Control Board Check Procedure." 1. See "II. 3. [d] Control Board Check Procedure." 1. See "II. 3. [d] Control Board Check Procedure."...

  • Page 35: [B] Evaporator Is Frozen

    1. Adjust or replace. See "V. 9. Adjustment of Water Regulating Valve." [b] EVAPORATOR IS FROZEN UP 1. See "II. 3. [d] Control Board Check Procedure." 1. See "V. 17. Thermistor." 1. See "II. 3. [c] Controls and Adjustments, b) Harvest Timer."...

  • Page 36: [C] Low Ice Production

    1. See "II. 3. [d] Control Board Check Procedure." [c] LOW ICE PRODUCTION a) See chart [b] [1] and check float switch, fill and harvest water valves, control board, water pump, spray tubes, evaporator, and expansion valve. b) See chart [a] [1] and check dirty air filter or condenser, ambient or water temperature, refrigerant charge, water pressure, and condenser water regulating valve (water-cooled model only).

  • Page 37: [E] Other

    a) See chart [b] [1] & [3] and check float switch, fill and harvest water valves, control board, spray tubes, water system, refrigerant charge, and expansion valve. [e] OTHER 1. See "II. 6. [b] Bin Control Check Procedure." c) Ice Cube Guide, Water Tank, Deflector...

  • Page 38: Removal And Replacement

    V. REMOVAL AND REPLACEMENT 1. SERVICE FOR REFRIGERANT LINES [a] SERVICE INFORMATION 1) Allowable Compressor Opening Time and Prevention of Lubricant Mixture [R404A] The compressor must not be opened more than 15 minutes in replacement or service. Do not mix lubricants of different compressors even if both are charged with the same refrigerant, except when they use the same lubricant.

  • Page 39: [B] Refrigerant Recovery

    7) Evacuation, Vacuum Pump and Refrigerant Charge [R404A] Never allow the oil in the vacuum pump to flow backward. The vacuum level and vacuum pump may be the same as those for the current refrigerants. However, the rubber hose and gauge manifold to be used for evacuation and refrigerant charge should be exclusively for R404A.

  • Page 40: Brazing

    2. BRAZING Note: All brazing connections inside the bin are clear coated. Sandpaper the brazing connections before unbrazing the components. Use a good abrasive cloth to remove the coating. 3. COMPRESSOR 1) Turn off the power supply. 2) Remove the panels and water tank. See "V. 14. WATER TANK."...

  • Page 41: Drier

    15) Connect the terminals and replace the terminal cover in its correct position. 16) Replace the panels and water tank in their correct positions. 17) Turn on the power supply. Note: Hoshizaki recommends that compressor starting electrics are always replaced at the same time as the compressor. 4. DRIER 1) Turn off the power supply.

  • Page 42: Hot Gas Valve

    5) Remove the drier using brazing equipment. 6) Braze the new drier, with the arrow on the drier in the direction of the refrigerant flow. Use nitrogen gas at a pressure of 20 to 30 kPa when brazing tubings. Braze in an access valve using a tee if necessary.

  • Page 43: Expansion Valve

    8) Install the new drier (see "V. 4. DRIER"). 9) Check for leaks using nitrogen gas (970 kPa) and soap bubbles. 10) Evacuate the system and charge it with refrigerant (see "V. 1. [c] EVACUATION AND RECHARGE"). 11) Attach the solenoid coil to the valve body, and secure it with the screw. 12) Connect the lead wires.

  • Page 44: Evaporator

    9) Evacuate the system, and charge it with refrigerant. For air-cooled and water-cooled models, see the nameplate for the required refrigerant charge. 10) Attach the expansion valve bulb to the suction line in the same location as the previous bulb. The bulb should be at the 12 o'clock position on the tube. Be sure to secure the bulb with the clamp and holder and to insulate it.

  • Page 45: Water Regulating Valve - Water-Cooled Model Only

    14) Turn on the power supply. 8. WATER REGULATING VALVE – WATER-COOLED MODEL ONLY 1) Turn off the power supply. 2) Remove the panels. 3) Close the condenser water supply line shut-off valve, then 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 46: Adjustment Of Water Regulating Valve - Water-Cooled Model Only

    17) Check for water leaks. 18) Replace the panels in their correct positions. 19) Turn on the power supply. 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.

  • Page 47: Pump Motor

    Screw Screw 8) Turn on the power supply. (Remove) (Loosen) Screw Fan Motor Fan Motor Bracket Fan Blade Cover 11. PUMP MOTOR 1) Turn off the power supply. 2) Remove the panels and front insulation. 3) Disconnect the connector of the pump motor lead. 4) Remove the thumbscrew securing the pump motor.

  • Page 48: Water Valve

    7) Remove the hose band connecting the discharge outlet and pull off the rubber hose. 8) Install the new motor in the reverse order of the removal procedure. 9) Replace the panels and front insulation in their correct positions. 10) Turn on the power supply. 12.

  • Page 49: Water Tank

    7) Remove the two mounting screws. 8) Install the new valve in the reverse order of the removal procedure. 9) Open the water supply tap. 10) Plug in the icemaker or connect the power source. 11) Check for leaks. 12) Refit the panels in their correct positions. 14.

  • Page 50: Float Switch

    9) Install the new water tank in the reverse order of the removal procedure. 10) Refit the panels in their correct positions. 11) Turn on the power supply. 15. FLOAT SWITCH 1) Remove the pump motor bracket. See "V. 14. WATER TANK." 2) Pull up the pump motor bracket from the water tank.

  • Page 51: Bin Control Switch

    4) Remove the two mounting screws, and release the float switch from the tabs on the bracket. Screws 5) Install the new float switch in the reverse order of the Float Switch removal procedure. Packing 6) Refit the panels in their correct positions. 7) Turn on the power supply.

  • Page 52: Thermistor

    7) While pulling up the bin control lead, hook the bin control on the right side interior wall. Then push the bin control up against the bottom of the unit, and slide to the back until it snaps in place. Make sure the slotted holes at the right side of the bin control are securely placed on the collars at the bottom of the unit.

  • Page 53: Control Box

    3) Disconnect the connector of the thermistor lead (orange). 4) Remove the ties, insulation, thermistor holder, and thermistor in this order. 5) Remove the old sealant from the thermistor holder and suction pipe. 6) Wipe off any moisture or condensation from the suction pipe surfaces. 7) Press a tube of the sealant KE 60RTV, manufactured by Shin-Etsu Silicones, to the recess of the thermistor holder.
  • Page 54 5) Refit the removed parts in the reverse order of the removal procedure. Screws Control Box Cover Screw Control Box Note: After replacing the components inside the control box, connect and tie the wires properly in their correct position. Especially make sure that the harness does not press the push buttons on the control board.

  • Page 55: [A] Control & Service Switch

    [a] CONTROL & SERVICE SWITCH 1) Disconnect the tab terminals and remove the nut securing the power switch. 2) Install the new switch in the reverse order of the removal procedure. 3) To prevent miswiring, check the terminal numbers and lead wire colors with the wiring label.

  • Page 56: [G] Starter

    [g] STARTER 1) Disconnect the terminals, remove the mounting screw. 2) Install the new starter in the reverse order of the removal procedure. 3) To prevent miswiring, check the terminal numbers and lead wire colors with the wiring label. [h] RUN CAPACITOR 1) Disconnect the terminals on the starter and remove the nut securing the run capacitor.
  • Page 57 Tabs Hose Band Water Supply Tube (under Spray Tube) Spray Tube Hose Hose Band 6) The spray tube is easily cleanable by removing the black rubber caps on the ends. 7) Remove the hose band connecting the water supply tube. 8) Pull the water supply tube towards you.

  • Page 58: Cleaning And Maintenance Instructions

    1. CLEANING [a] CLEANING PROCEDURE 1) Dilute approximately 9.5 fl. oz. (281 ml) of recommended cleaner Hoshizaki “Scale Away” or “LIME-A-WAY” (Economics Laboratory, Inc.) with 1.8 gallon (6.8 lit.) of water. 2) Remove all ice from the evaporator and the storage bin/dispenser unit.
  • Page 59 7) Remove the front panel then remove the front insulation (the large insulation panel in front of the evaporator) by lifting up the panel slightly and pulling it towards you. 8) In bad or severe water conditions, clean the float switch as described below. Otherwise, continue to step 9.
  • Page 60 g. Wipe down the float switch housing, shaft and float with cleaning solution. Rinse the parts thoroughly with clean water. h. Replace the float switch in its correct position. i. Replace the removed parts in the reverse order of which they were removed. 9) Pour the cleaning solution into the water tank.

  • Page 61: [B] Sanitizing Procedure

    31) Remove the front panel. 32) Repeat steps 18 through 31 three more times to rinse thoroughly. Note: If you do not sanitize the icemaker, go to step 14 in "Sanitizing Procedure." [b] SANITIZING PROCEDURE – FOLLOWING CLEANING PROCEDURE 1) Dilute a 5.25% sodium hypochlorite solution (chlorine bleach) with water (add approximately 0.9 fl.

  • Page 62: [A] Stainless Steel Exterior

    [a] STAINLESS STEEL EXTERIOR To prevent corrosion, wipe the exterior occasionally with a clean, soft cloth. Use a damp cloth containing a neutral cleaner to wipe off oil or dirt build up. [b] STORAGE BIN AND SCOOP * Wash your hands before removing ice. Use the plastic scoop provided (bin accessory). * The storage bin/dispenser unit is for ice use only.
  • Page 63 2) Move the control switch on the control box to the "OFF" position. 3) Wait 3 minutes. 4) Move the control switch to the "ICE" position. 5) Replace the front panel in its correct position and turn on the power supply. 6) Allow 5 minutes for the icemaker to fill with water and the water pump to start operating.
  • Page 64 4) Turn off the power supply and remove the front panel. 5) Move the control switch to the "OFF" position. 6) Replace the front panel in its correct position. 7) Remove all ice from the storage bin/dispenser unit, and clean the storage bin/dispenser unit.

This manual is also suitable for:

Kmd-270aa

Table of Contents