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Hoshizaki KMD-410MAH, KMD-410MWH manual Harvest Control - Thermistor

Models: KMD-410MWH KMD-410MAH

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4. 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 or momentarily stop the pump motor during the freeze cycle, or to extend the harvest cycle time. 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.

Check a thermistor for resistance by using the following procedure:

1)Disconnect the thermistor (orange wires) at the 2-pin connector on the control box. See Fig. below.

2)Remove the thermistor. See "V. 17. THERMISTOR."

3)Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes.

4)Check for a resistance between thermistor leads. Normal reading is within 3.5 to 7 k. Replace the thermistor if it exceeds the normal reading.

Thermistor Connector (orange wires)

Bin Control Wires (black)

Float Switch Connector (red wires)

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Hoshizaki KMD-410MAH, KMD-410MWH manual Harvest Control - Thermistor

Contents

Page Page CONTENTS PAGEV. REMOVAL AND REPLACEMENT 1. 10-MINUTE DIAGNOSTIC PROCEDURE2. DIAGNOSTIC CHARTS 1. SERVICE FOR REFRIGERANT LINESI. SPECIFICATIONS 1. SPECIFICATIONS a KMD-410MAH air-cooledb KMD-410MWH water-cooled II. GENERAL INFORMATION 1. CONSTRUCTION a KMD-410MAHHigh Side Thermistor Access Valve Low Side Cube Guide Water Tank b KMD-410MWHWater Supply Tube Spray Guide Spray Tube Cleaning Valve Access Valve Pump Motor Float Switch Bin Control Switchb INITIAL HARVEST CYCLE 2. SEQUENCE OF OPERATIONa ONE MINUTE FILL CYCLE c FREEZE CYCLEe NORMAL HARVEST CYCLE KMD-410MAH, 410MWH 4. Drain Cycle3. CONTROL BOARD Control Board Auxiliary Code V1 or Earlier V2 or Later a CONTROL BOARD LAYOUT#4 Harvest Water Valve #5 Freeze Water Valve #1, 2, 3 Float Switch Part Number P00013-02 P01771-02 TypeHKM2006V003c High Temperature Safety b FEATURES a Maximum Water Supply Period - 6 minutesb Harvest Backup Timer and Freeze Timer d Low Water Safetyf LED Lights and Audible Alarm Safeties c CONTROLS AND ADJUSTMENTS a Default Dip Switch Settings b Harvest Timer S1 dip switch 1d Drain Frequency Control S1 dip switch 5 c Drain Timer S1 dip switch 3e Water Saver Timer S1 dip switch 7 h Refill Counter S2 dip switch 2, 3, & 4 Program Ver. 2.5 or earlier f Freeze Timer S1 dip switch 9g Pump-Out Pump Motor Delay S2 dip switch i Factory Use S2 dip switch 5 Program Ver. 2.5 or earliern Overfreeze Detection Control S2 dip switch 5 Program Ver. 3.1, Ver k Harvest Promotion Control S2 dip switch 2 Program Ver. 3.1, Verl Refill Counter S2 dip switch 3 Program Ver. 3.1, Ver Control Board P01771-02o Anti-Slush Control S2 dip switch 6 Program Ver p Anti-Slush Control S2 dip switch 6 Program Verd CONTROL BOARD CHECK PROCEDURE e CONTROL BOARD REPLACEMENT4. HARVEST CONTROL - THERMISTOR c FLOAT SWITCH CHECK PROCEDURE 5. FLOAT SWITCHb CLEANING a EXPLANATION OF OPERATION6. BIN CONTROL b BIN CONTROL CHECK PROCEDUREa EXPLANATION OF OPERATION b SERVICE SWITCH 7. SWITCHESa CONTROL SWITCH 1 DRAINIII. TECHNICAL INFORMATION 1. WATER CIRCUIT AND REFRIGERANT CIRCUIT 2. WIRING DIAGRAM The magnetic contactor wiring depends on the contactor model3. TIMING CHARTCONTROLLER 4. PERFORMANCE DATA a KMD-410MAHb KMD-410MWH IV. SERVICE DIAGNOSIS 1. 10-MINUTE DIAGNOSTIC PROCEDURE Page 2. DIAGNOSTIC CHARTS a NO ICE PRODUCTION1. See II. 3. d Control Board Check Procedure 1. See II. 3. d Control Board Check Procedure1. See II. 4. Harvest Control Thermistor 1. See II. 3. d Control Board Check Procedure 1. See II. 3. d Control Board Check Procedure1. See II. 3. d Control Board Check Procedure 1. See II. 3. d Control Board Check Procedureb EVAPORATOR IS FROZEN UP 9. Adjustment of Water Regulating Valvec LOW ICE PRODUCTION d ABNORMAL ICEe OTHER c Ice Cube Guide, Water Tank, Deflector5 Service Parts for R404A V. REMOVAL AND REPLACEMENT 1. SERVICE FOR REFRIGERANT LINESa SERVICE INFORMATION 6 Replacement Copper Tubing R404A8 Refrigerant Leak Check b REFRIGERANT RECOVERY7 Evacuation, Vacuum Pump and Refrigerant Charge R404A c EVACUATION AND RECHARGE1 Turn off the power supply 2. BRAZING3. COMPRESSOR 2 Remove the panels and water tank. See V. 14. WATER TANK4. DRIER 5. HOT GAS VALVE 6. EXPANSION VALVE 7. EVAPORATOR 8. WATER REGULATING VALVE - WATER-COOLED MODEL ONLY 9. ADJUSTMENT OF WATER REGULATING VALVE WATER-COOLED MODEL ONLY 10. FAN MOTOR11. PUMP MOTOR 13. DRAIN VALVE, CLEANING VALVE 12. WATER VALVE14. WATER TANK 11 Refit the panels in their correct positions 15. FLOAT SWITCH12 Turn on the power supply 1 Remove the pump motor bracket. See V. 14. WATER TANK16. BIN CONTROL SWITCH 17. THERMISTOR 18. CONTROL BOX Screws Control Box Cover Screw Control Box c FUSE HOLDER a CONTROL & SERVICE SWITCHb FUSE d CONTROL BOARDh RUN CAPACITOR 19. SPRAY TUBE, WATER SUPPLY TUBE, SPRAY GUIDEg STARTER i START CAPACITOR7 Remove the hose band connecting the water supply tube VI. CLEANING AND MAINTENANCE INSTRUCTIONS 1. CLEANING a CLEANING PROCEDUREa. Loosen the two thumbscrews securing the pump motor bracket b. Disconnect the discharge hose10 Move the service switch to the WASH position h. Replace the float switch in its correct position9 Pour the cleaning solution into the water tank 12 Turn on the power supply to start the washing process2. MAINTENANCE b SANITIZING PROCEDURE - FOLLOWING CLEANING PROCEDUREb STORAGE BIN AND SCOOP 3. PREPARING THE ICEMAKER FOR LONG STORAGEa STAINLESS STEEL EXTERIOR c AIR FILTERS AIR-COOLED MODEL ONLY2. Remove the water from the icemaker water supply line 3. Drain the water tank6 Replace the front panel in its correct position 4 Turn off the power supply and remove the front panel5 Move the control switch to the OFF position 8 Close the icemaker water supply line drain valve