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Hoshizaki KM-280MAF, Service Manual

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Hoshizaki KM-280MAF Service Manual Download Page 4

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V.  REMOVAL AND REPLACEMENT OF COMPONENTS ........................................... 33

1.  SERVICE FOR REFRIGERANT LINES ................................................................. 33

[a] REFRIGERANT RECOVERY ........................................................................ 33
[b] EVACUATION AND RECHARGE ................................................................... 33

2.   BRAZING ............................................................................................................. 34
3.  REMOVAL AND REPLACEMENT OF COMPRESSOR ....................................... 35
4.  REMOVAL AND REPLACEMENT OF DRIER ...................................................... 36
5.  REMOVAL AND REPLACEMENT OF EXPANSION VALVE ............................... 37
6.  REMOVAL AND REPLACEMENT OF HOT GAS VALVE ........................................
      AND/OR LINE VALVE .......................................................................................... 38
7.  REMOVAL AND REPLACEMENT OF EVAPORATOR ........................................ 39
8.  REMOVAL AND REPLACEMENT OF WATER-REGULATING VALVE .................
      - WATER COOLED MODEL ONLY ..................................................................... 40
9.  ADJUSTMENT OF WATER-REGULATING VALVE ...............................................
      - WATER COOLED MODEL ONLY ..................................................................... 41

10.  REMOVAL AND REPLACEMENT OF THERMISTOR ........................................ 42
11.  REMOVAL AND REPLACEMENT OF FAN MOTOR ........................................... 43
12.  REMOVAL AND REPLACEMENT OF WATER VALVE ...................................... 44
13.  REMOVAL AND REPLACEMENT OF PUMP MOTOR ........................................ 44
14.  REMOVAL AND REPLACEMENT OF SPRAY TUBE ......................................... 45

VI.  MAINTENANCE AND CLEANING INSTRUCTIONS ............................................. 46

1.  PREPARING THE ICEMAKER FOR LONG STORAGE...................................... 46
2.  CLEANING AND SANITIZING PROCEDURES .................................................. 48

[a] CLEANING PROCEDURE ............................................................................ 49
[b] SANITIZING PROCEDURE ........................................................................... 50

3.  MAINTENANCE ................................................................................................... 51

Summary of Contents for KM-280MAF

Page 1: ...NO ISSUED REVISED MAY 25 1999 73084 HOSHIZAKI MODULAR CRESCENT CUBER MODEL DEC 13 2003 KM 280MAF KM 280MWF SERVICE MANUAL ...

Page 2: ...233 1940TechnicalService 770 487 2331 Fax 770 487 3360 NOTE Toexpediteassistance allcorrespondence communicationMUST includethefollowing information Model Number Serial Number Complete and detailed explanation of the problem 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 concern...

Page 3: ...ooled 6 II GENERAL INFORMATION 7 1 CONSTRUCTION 7 a KM 280MAF 7 b KM 280MWF 8 2 CONTROLLER BOARD 9 a SOLID STATE CONTROL 9 b CONTROLLER BOARD 9 c SEQUENCE 13 d CONTROLS AND ADJUSTMENTS 16 e CHECKING CONTROLLER BOARD 19 III TECHNICAL INFORMATION 21 1 WATER CIRCUIT AND REFRIGERANT CIRCUIT 21 a KM 280MAF 21 b KM 280MWF 22 2 WIRING DIAGRAMS 23 3 TIMING CHART 24 4 PERFORMANCE DATA 26 a KM 280MAF Air co...

Page 4: ...VAPORATOR 39 8 REMOVAL AND REPLACEMENT OF WATER REGULATING VALVE WATER COOLED MODEL ONLY 40 9 ADJUSTMENT OF WATER REGULATING VALVE WATER COOLED MODEL ONLY 41 10 REMOVAL AND REPLACEMENT OF THERMISTOR 42 11 REMOVAL AND REPLACEMENT OF FAN MOTOR 43 12 REMOVAL AND REPLACEMENT OF WATER VALVE 44 13 REMOVAL AND REPLACEMENT OF PUMP MOTOR 44 14 REMOVAL AND REPLACEMENT OF SPRAY TUBE 45 VI MAINTENANCE AND CLE...

Page 5: ...5 I SPECIFICATIONS 1 KM 280MAF Air cooled We reserve the right to make changes in specifications and design without prior notice ...

Page 6: ...6 2 KM 280MWF Water cooled We reserve the right to make changes in specifications and design without prior notice ...

Page 7: ...FORMATION 1 CONSTRUCTION a KM 280MAF Spray Tube Water Supply Inlet Control Switch Condenser Bin Control Thermostat Hot Gas Valve Expansion Valve Fan Motor Condenser Compressor Drier Float Switch Control Box Water Pump ...

Page 8: ...8 Spray Tube Water Supply Inlet Control Switch Water Regulator Bin Control Thermostat Expansion Valve Hot Gas Valve Compressor Float Switch Drier Water Pump Control Box b KM 280MWF ...

Page 9: ...board 3 Do not touch the electronic devices on the board or the back of the board to prevent damage to the board 4 Do not change wiring and connections Do not misconnect K3 K4 and K5 because the same connector is used for the Thermistor and Float Switch K4 is not connected 5 Always replace the whole board assembly when it goes bad 6 Do not short out power supply to test for voltage PART NUMBER TYP...

Page 10: ...et the Safety 4 Low Water Safety If the Pump Motor is operated without water the mechanical seal can fail To prevent this type of failure the Controller Board checks the position of the Float Switch at the end of the initial one minute water fill cycle and at the end of each defrost cycle If the Float Switch is in the up position electrical circuit closed the Controller Board changes to the ice ma...

Page 11: ...ck for open thermistor HGV not opening TXV leaking by low charge or inefficient compressor 3 beeps every 3 sec Freeze Back Up Timer Freeze 60 minutes Yellow LED marked 60 MIN energizes Check for F S stuck closed up WV leaking by HGV leaking by TXV not feeding prop erly low charge or inefficient compressor To manually reset the above safeties depress white alarm reset button with the power supply O...

Page 12: ...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 7 8 must remain in the OFF position ...

Page 13: ...utes in freeze cycle Ready to complete freeze cycle when Float Switch circuit opens 4 Defrost Timer stops counting Defrost cycle is completed freeze cycle starts and Line Valve opens IMPORTANT Board never accepts freeze completion signal within the first 5 minutes in freeze cycle IMPORTANT 1 Board never accepts defrost completion signal within the first 2 minutes in defrost cycle 2 Defrost cycle t...

Page 14: ...r Valve opening is limited to 6 minutes 5 After the first 5 minutes in freeze cycle Ready to complete freeze cycle when Float Switch circuit opens 4 Defrost Timer stops counting Defrost cycle is completed freeze cycle starts and Line Valve opens IMPORTANT Board never accepts freeze completion signal within the first 5 minutes in freeze cycle IMPORTANT 1 Board never accepts defrost completion signa...

Page 15: ... 4 After the first 5 minutes in freeze cycle Ready to complete freeze cycle when Float Switch circuit opens 3 Defrost Timer stops counting Defrost cycle is completed freeze cycle starts and Line Valve opens IMPORTANT Board never accepts freeze completion signal within the first 5 minutes in freeze cycle IMPORTANT 1 Board never accepts defrost completion signal within the first 2 minutes in defrost...

Page 16: ...determines the time to restrain completion of a defrost cycle i e the minimum defrost time Switch Nos 5 and 6 Used for adjustment of the Drain Counter The Pump Motor drains the Water Tank at the frequency determined by the Drain Counter Switch Nos 7 and 8 Used only for checking the Controller Board Usually set in OFF position Switch Nos 9 and 10 Used for adjustment of Freeze Timer The Freeze Timer...

Page 17: ... the connector K3 on the board ii Remove the Thermistor See V 10 REMOVAL AND REPLACEMENT OF THER MISTOR iii Immerse the Thermistor sensor portion in a glass containing ice and water for 2 or 3 minutes iv Check for a resistance between Thermistor leads Normal reading is within 3 5 to 7 kΩ Replace the Thermistor if it exceeds the normal reading 2 Defrost Timer No adjustment is required under normal ...

Page 18: ...strain defrost completion 4 Drain Counter CAUTION 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 However where water quality is bad and the icemaker needs a pump drain more often the Drain Counter can be adjusted as shown in the table below SETTING FREQUENCY Dip Switch Dip S...

Page 19: ...e sequence with the icemaker operating 2 Visually check the Controller Board by using the following procedures i Adjust the Defrost Timer to minimum position Disconnect the Thermistor from the Controller Board Connect a 1 5 kΩ 3 5 kΩ resistor to the Connector K3 pins 1 and 2 and energize the unit 5 Freeze Timer CAUTION Adjust to proper specification or the unit may not operate correctly Two new di...

Page 20: ...With power OFF place S3 on and switch power to ICE The correct lighting sequence should be none 2 3 4 1 and 4 normal sequence every 5 seconds S3 should remain in the OFF position for normal operation 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 Cont...

Page 21: ...21 III TECHNICAL INFORMATION 1 WATER CIRCUIT AND REFRIGERANT CIRCUIT a KM 280MAF ...

Page 22: ...22 b KM 280MWF ...

Page 23: ...23 2 WIRING DIAGRAMS a KM 280MAF KM 280MWF KM 280MAF Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 KM 280MWF Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 ...

Page 24: ...24 3 TIMING CHART NOTE The icemaker does not complete a defrost cycle in the first 2 or 3 minutes See II 2 d CONTROLS AND ADJUSTMENTS KM 1200MRE SRE KM 2000SRE3 ...

Page 25: ... Pump Motor waits for 2 seconds before starting a drain cycle See II 2 d CONTROLS AND ADJUSTMENTS 2 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes See II 2 d CONTROLS AND ADJUSTMENTS ...

Page 26: ...ATA a KM 280MAF 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 27: ...280MWF 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 28: ...ssure 1 Bad contacts 1 Check for continuity and Control replace f Transformer 1 Thermal fuse blown out 1 Replace or coil winding opened g Wiring to 1 Loose connections or 1 Check for continuity and Controller Board open replace h Thermistor 1 Leads short circuit or 1 See II 2 d CONTROLS open and High Temperature AND ADJUSTMENTS Safety operates 1 Defrost Control i Hot Gas Solenoid 1 Continues to op...

Page 29: ...er water pressure 4 Check and get too low or off Water recommended pressure cooled model only 5 Fan not operating Except 5 See chart 1 6 water cooled model 6 Refrigerant line or 6 Clean and replace Drier components plugged c Water Regulator 1 Set too high 1 Adjust lower d Overload Protector 1 Bad contacts 1 Check for continuity and replace 2 Voltage too low 2 Increase voltage 3 Refrigerant overcha...

Page 30: ...peller 5 Replace and clean 6 Mechanical Seal worn out 6 Check and replace e Controller Board 1 Defective 1 See II 2 e CHECKING CONTROLLER BOARD 6 Fan Motor will a Fan Motor 1 Motor winding opened 1 Replace not start or is 2 Bearing worn out 2 Replace not operating 3 Wiring to Fan Motor 3 Check for loose connection or open and replace 4 Defective Capacitor 4 Replace 5 Fan blade bound 5 Check and re...

Page 31: ... to open in 1 Check operation in harvest cycle harvest cycle and replace f Thermistor 1 Out of position or loose 1 See V 11 REMOVAL attachment AND REPLACEMENT OF THERMISTOR g Controller Board 1 Defrost Timer is set too 1 Adjust longer referring short to II 2 d CONTROLS AND ADJUSTMENT 2 Defrost Timer 2 Defective 2 See II 2 e CHECKING CONTROLLER BOARD 3 Others a Spray Tubes 1 Clogged 1 Clean 2 Out o...

Page 32: ... out 1 Replace noise b Fan Motor 1 Bearings worn out 1 Replace 2 Fan blade deformed 2 Replace fan blade 3 Fan blade does not move 3 Replace freely c Compressor 1 Bearings worn out or 1 Replace cylinder valve broken 2 Mounting pad out of 2 Reinstall position d Refrigerant Lines 1 Rub or touch lines or other 1 Replace surfaces 3 Ice in storage a Bin Drain 1 Plugged 1 Clean bin often b Ice machine an...

Page 33: ... side and one on the high side line Using proper refrigerant practices recover the refrigerant from the Access Valves and store it in an approved container Do not discharge the refrigerant into the atmosphere b EVACUATION AND RECHARGE R 404A 1 Attach Charging Hoses a Service Manifold and a Vacuum Pump to the system Be sure to connect charging hoses to both High and Low side Access Valves IMPORTANT...

Page 34: ... Hoses and Service Manifold 10 Cap the Access Valves to prevent a possible leak 2 BRAZING DANGER 1 Refrigerant R 404A itself is not flammable at atmospheric pressure and temperatures up to 176 F 2 Refrigerant R 404A itself is not explosive or poisonous However when exposed to high temperatures open flames R 404A can be decom posed to form hydrofluoric acid and carbonyl fluoride both of which are h...

Page 35: ...power supply 2 Remove the panels 3 Recover the refrigerant and store it in an approved container 4 Remove the Terminal Cover on the Compressor and disconnect the Compressor Wiring 5 Remove the Discharge and Suction Pipes using brazing equipment 6 Remove the Hold down Bolts Washers and Rubber Grommets 7 Slide and remove the Compressor Unpack the new Compressor package Install the new Compressor 8 A...

Page 36: ...e 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 Drier 5 Install the new Drier with the arrow on the Drier in the direction of the refrigerant flow Use nitrogen gas at the pressure of 3 4 PSIG when brazing the tubings 6 Check for leaks using nitrogen gas...

Page 37: ...alve 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 WARNING Always protect the valve body by using a damp cloth to prevent the valve from overheating Do not braze with the valve body exceeding 250 F 7 Install the new Drier 8 Check for leaks using nitrogen gas 140 PSIG and soap bubbles 9 Evacuate...

Page 38: ...using a damp cloth to prevent the valve from overheating Do not braze with the valve body exceeding 250 F 7 Install the new Drier 8 Check for leaks using nitrogen gas 140 PSIG and soap bubbles 9 Evacuate the system and charge it with refrigerant See the Nameplate for the required refrigerant charge 10 Cut the leads of the Solenoid allowing enough lead length to reconnect using closed end connector...

Page 39: ...oved container 4 Remove the Spray Tubes and the Insulations at the U shaped notch where the refrigeration tubings go through the chassis 5 RemovetheInsulationTube anddisconnecttheEvaporatorInletTubingattheTeenext to the Expansion Valve 6 Lift up the Evaporator and disconnect the Evaporator Outlet Tubing 7 Install the new Evaporator 8 Install the new Drier 9 Check for leaks using nitrogen gas 140 P...

Page 40: ...r 5 Disconnect the Capillary Tube at the Condenser outlet using brazing equipment 6 Disconnect the Flare connections of the valve 7 Remove the screws and the valve from the Bracket 8 Install the new valve and braze the Capillary Tube 9 Install the new Drier 10 Check for leaks using nitrogen gas 140 PSIG and soap bubbles 11 Evacuate the system and charge it with refrigerant See the Nameplate for th...

Page 41: ...enser drain temperature 2 Rotate the adjustment screw by using a flat blade screwdriver so that the pressure gauge shows 270 PSIG or the thermometer reads 104 115 F 5 minutes after a freeze cycle or icemaking process starts When the pressure exceeds 270 PSIG or the condenser drain temperature exceeds 115 F rotate the adjustment screw counter clockwise See Fig 1 3 Check that the pressure or the con...

Page 42: ...ol Box Cover 4 Disconnect the Thermistor leads from the K3 Connector on the Controller Board 5 Remove the Plastic Cable Ties Foam Insulation Thermistor Holder and Thermistor See Fig 2 6 Scrape away the old sealant on the Thermistor Holder and the Suction Pipe 7 Wipe off moisture or condensation on the Suction Pipe 8 Smoothly apply recommended sealant KE4560RTV Part Code 60Y000 11 or 4A0683 01 to t...

Page 43: ...s 13 Turn on the power supply 11 REMOVAL AND REPLACEMENT OF FAN MOTOR Note When replacing a Fan Motor with defective winding it is recommended that a new capacitor be installed 1 Turn off the power supply 2 Remove the panels 3 Remove the closed end connectors from the Fan Motor leads 4 Remove the Fan Motor Bracket and Fan Motor 5 Install the new Fan Motor and replace the removed parts in the rever...

Page 44: ...eplace the removed parts in the reverse order of which they were removed 9 Open the Water Supply Line Shut off Valve 10 Turn on the power supply 11 Check for leaks 12 Replace the Top and Front Panels in their correct positions 13 REMOVAL AND REPLACEMENT OF PUMP MOTOR 1 Turn off the power supply 2 Remove the Front Panel 3 Remove the Base Cover 4 Drain the Water Tank by removing one end of the Pump ...

Page 45: ...for leaks 14 Replace the Base Cover in its correct position 15 Replace the Front Panel in its correct position 14 REMOVAL AND REPLACEMENT OF SPRAY TUBE 1 Turn off the power supply 2 Remove the Front Panel and the Insulation Panel 3 Remove the Rubber Hose from the Spray Tube Water Supply Pipe 4 Release the Clamp and disconnect the Rubber Hose 5 Remove the Spray Tube by squeezing the side tab 6 Inst...

Page 46: ...ays it is sufficient to only move the Control Switch to the OFF position unless the icemaker will be at sub freezing temperatures 1 On water cooled model only first remove the water from the water cooled condenser 1 Remove the Front Panel 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 Allow 5 minutes for the icemake...

Page 47: ...dioxide supply to the Potable Water Line Drain Valve 7 Move the Control Switch to the ICE position 8 Blow the potable water line out using compressed air or carbon dioxide 3 Drain the Potable Water Tank 1 Turn off the power supply 2 Move the Control Switch to the OFF position 3 Drain the Water Tank by removing the base cover and one end of the pump tubing See Fig 3 4 Replace the removed parts in t...

Page 48: ...o not use ammonia type cleaners 3 Always wear liquid proof gloves for safe handling of the cleaning and sanitizing solution This will prevent irritation in case the solution comes into contact with skin IMPORTANT 1 The Cleaning Valve is used to allow solution flow to the inside of the Evaporator during the cleaning and sanitizing operation It should be closed for all icemaking operations The Compr...

Page 49: ...g one end of the Pump Tubing See Fig 3 7 Replace the removed parts in their correct positions 8 Pour the cleaning solution into the Water Tank 9 Fully open the Cleaning Valve on the left side wall of the machine compartment 10 Move the Control Switch on the Control Box to the WASH position 11 Replace the Insulation Panel and the Front Panel in their correct positions 12 Turn on the power supply an...

Page 50: ...lation Panel when you proceed to b SANITIZING PROCEDURE 28 Repeat the above steps 17 through 29 three more times to rinse thoroughly Note If you do not sanitize the icemaker go to step 9 in b SANITIZING PROCEDURE b SANITIZING PROCEDURE Following Cleaning Procedure 1 Dilute a 5 25 Sodium Hypochlorite solution chlorine bleach with water Add 1 5 fl oz of sanitizer to 3 gal of water 2 Remove the Insul...

Page 51: ...ruction manual and labels provided with the icemaker 1 Stainless Steel Exterior To prevent corrosion wipe the exterior occasionally with a clean and soft cloth Use a damp cloth containing a neutral cleaner to wipe off oil or dirt build up 2 Storage Bin and Scoop Wash your hands before removing ice Use the plastic scoop provided The Storage Bin is for ice use only Do not store anything else in the ...

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