KM-280M H serv new - HOSHIZAKI INTERNATIONAL

1 HOSHIZAKIMODULAR CRESCENT CUBERMODELKM-280 MAHKM-280 MWHSERVICE MANUALNO. 73117 ISSUED: AUG. 15, 2004 REVISED:2 IMPORTANTOnly qualified service technicians should attempt to service or maintain this service or maintenance should be undertaken until the technician has thoroughlyread this Service AMERICA, Highway 74 SouthPeachtree City, GA 30269 Attn: HOSHIZAKI Technical Support DepartmentPhone: 1-800-233-1940 Technical Service(770) 487-2331 Fax:(770) 487-3360 NOTE: To expedite assistance, all correspondence/communication MUST include thefollowing information: Model Number Serial Number Complete and detailed explanation of the problemHOSHIZAKI provides this manual primarily to assist qualified service technicians in theservice and maintenance of the the reader have any questions or concerns which have not been satisfactorilyaddressed, please call or write to the HOSHIZAKI Technical Support Department Please review this manual.

2 It should be read carefully before the icemaker is servicedor maintenance operations performed. Only qualified service technicians should serviceand maintain the icemaker. This manual should be made available to the technicianprior to service or PAGEI. 51. KM-280 MAH (Air-cooled).. 52a. KM-280 MWH (Water-cooled) Serial #L00001E - 62b. KM-280 MWH (Water-cooled) Serial # 7II. GENERAL 81. 8[a] KM-280 MAH (Air-cooled).. 8[b] KM-280 MWH (Water-cooled).. 92. CONTROLLER BOARD .. 10[a] SOLID-STATE 10[b] CONTROLLER 10[c] SEQUENCE .. 14[d] CONTROLS AND ADJUSTMENTS .. 17[e] CHECKING CONTROLLER BOARD .. 213. MECHANICAL BIN CONTROL .. 22[a] PROXIMITY 22[b] EXPLANATION OF 22[c] 23 III.

3 TECHNICAL 241. WATER CIRCUIT AND REFRIGERANT 24[a] KM-280 MAH .. 24[b] KM-280 MWH .. 252. WIRING 26[a] KM-280 MAH and KM-280 MWH .. 263. TIMING 284. PERFORMANCE DATA .. 30[a] KM-280 MAH .. 30[b] KM-280 MWH Serial #L00001E - M10134C .. 31[c] KM-280 MWH Serial #M20315D .. 324IV. SERVICE DIAGNOSIS .. 331. NO ICE PRODUCTION .. 332. EVAPORATOR IS FROZEN UP .. 363. LOW ICE PRODUCTION .. 374. ABNORMAL ICE .. 375. OTHERS .. 37V. REMOVAL AND REPLACEMENT OF COMPONENTS .. 381. SERVICE FOR REFRIGERANT LINES .. 38[a] REFRIGERANT RECOVERY .. 38[b] EVACUATION AND RECHARGE [R-404A] .. 382. BRAZING .. 393. REMOVAL AND REPLACEMENT OF COMPRESSOR .. 404. REMOVAL AND REPLACEMENT OF DRIER.

4 425. REMOVAL AND REPLACEMENT OF EXPANSION VALVE .. 426. REMOVAL AND REPLACEMENT OF HOT GAS VALVE AND .. LINE VALVE .. 437. REMOVAL AND REPLACEMENT OF 458. REMOVAL AND REPLACEMENT OF WATER-REGULATING VALVE .. - WATER COOLED MODEL ONLY .. 469. ADJUSTMENT OF WATER-REGULATING VALVE .. - WATER COOLED MODEL ONLY .. 4710. REMOVAL AND REPLACEMENT OF THERMISTOR .. 4811. REMOVAL AND REPLACEMENT OF FAN MOTOR .. 4912. REMOVAL AND REPLACEMENT OF WATER VALVE .. 5013. REMOVAL AND REPLACEMENT OF PUMP MOTOR .. 5014. REMOVAL AND REPLACEMENT OF SPRAY TUBES .. 51VI. CLEANING AND MAINTENANCE INSTRUCTIONS .. 521. PREPARING THE ICEMAKER FOR LONG STORAGE.

5 522. CLEANING .. 54[a] CLEANING PROCEDURE .. 55[b] SANITIZING PROCEDURE .. 573. MAINTENANCE .. 585I. SPECIFICATIONS1. KM-280 MAH (Air-cooled)Note: We reserve the right to make changes in specifications and design without prior KM-280 MWH (Water-cooled)Serial #L00001E- M10134 CNote: We reserve the right to make changes in specifications and design without prior KM-280 MWH (Water-cooled)Serial #M20315D -Note: We reserve the right to make changes in specifications and design without prior GENERAL INFORMATION1. CONSTRUCTION[a] KM-280 MAH (Air-cooled) Spray TubesWater Supply Inlet Control SwitchCondenserHot Gas Valve Expansion ValveFan MotorCondenser CompressorDrier Float SwitchControl Box Water PumpBin Control Thermostat(except models withMechanical Bin Control)MechanicalBin Control(except modelswith Thermostat)9[b] KM-280 MWH (Water-cooled) Spray TubesWater Supply Inlet Control SwitchWater Regulator Expansion ValveHot Gas Valve Compressor Float SwitchDrier Water PumpControl BoxBin Control Thermostat(except models withMechanical Bin Control)MechanicalBin Control(except modelswith Thermostat)102.

6 CONTROLLER BOARD[a] SOLID-STATE CONTROL1) A HOSHIZAKI exclusive solid-state control is employed in Modular Crescent ) A Printed Circuit Board (hereafter called Controller Board ) includes a stable and highquality control ) All models are pretested and factory-adjusted.[b] CONTROLLER BOARDCAUTION1. Fragile, handle very A controller board contains integrated circuits, which are susceptible tofailure due to static discharge. It is especially important to touch the metalpart of the unit when handling or replacing the Do not touch the electronic devices on the board or the back of the board toprevent damage to the Do not change wiring and connections. Do not misconnect K3, K4 and K5,because the same connector is used for the Thermistor (white), Float Switch(black), and Mechanical Bin Control (red).

7 (For machines with thermostat, there is no connection on K4.)5. Always replace the whole board assembly when it goes Do not short out power supply to test for NUMBERTYPE2A1410-01 HOS-001A (Control Products)Features of Control Products E Controller Board1) Maximum Water Supply Period - 6 minutesWater Solenoid Valve opening, in the Defrost (Harvest) Cycle, is limited by the defrosttimer. The Water Valve cannot remain open longer than themaximum period. The Water Valve can close in less than six minutes if the defrost cycle ) Defrost TimerThe defrost cycle starts when the Float Switch opens and completes the freeze cycle. Butthe Defrost Timer does not start counting until the Thermistor senses 48 F at the Evapora-tor outlet.

8 The period from the end of the freeze cycle up to the point of the Thermistor'ssensing varies depending on the ambient and water ) High Temperature Safety - 127 7 FThe temperature of the suction line in the refrigerant circuit is limited by the HighTemperature the defrost cycle the Evaporator temperature rises. The Thermistor senses48 F and starts the Defrost Timer. After the Defrost Timer counts down to zero,the normal freeze cycle begins. If the Evaporator temperature continues to rise,the Thermistor will sense the rise in temperature and at 127 7 F the Thermistoroperates the High Temperature High Temperature Safety shuts down the circuit and the icemaker High Temperature Safety protects the unit from excessive temperature.

9 The ControlBoard will Beep every 3 seconds. The white Reset Button on the Control Board must bepressed with power on to reset the ) Low Water SafetyIf the Pump Motor is operated without water, the mechanical seal can fail. To prevent thistype of failure, the Controller Board checks the position of the Float Switch at the end ofthe initial one minute water fill cycle and at the end of each defrost the Float Switch is in the up position (electrical circuit closed), the Controller Boardchanges to the ice making cycle. If the Float Switch is in the down position (electricalcircuit open), the Controller Board changes to a one minute water fill cycle before startingthe ice making cycle.

10 This method allows for a Low Water Safety shut down to protect theWater Pump from mechanical seal water-cooled model, if the water is shut off, the unit is protected by the High ) High Voltage CutoutThe maximum allowable supply voltage of this icemaker is limited by the High Voltage miswiring (especially on single phase 3 wire models) causes excessive voltage on theController Board, the High Voltage Cutout shuts down the circuit in 3 seconds and theicemaker automatically stops. When the proper supply voltage is resumed, the icemakerautomatically starts running again. The Control Board will signal this problem using 7 Beepsevery 3 ) LED Lights and Audible Alarm Safeties The red LED indicates proper control voltage and will remain on unless a control voltageproblem occurs.