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Hoshizaki KM-900MAF, Service Manual

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Hoshizaki KM-900MAF Service Manual Download Page 31

31

[b] KM-900MWF

Note:   Pressure Switch

Cut-out

412 ±

 PSIG

Cut-in

327 ± 21 PSIG

21
0

Summary of Contents for KM-900MAF

Page 1: ...SERVICE MANUAL NO ISSUED REVISED MAR 19 1999 73083 HOSHIZAKI MODULAR CRESCENT CUBER MODELS KM 900MAF KM 900MWF KM 900MRF KM 900MRF3 DEC 15 2003 ...

Page 2: ...0 233 1940TechnicalService 770 487 2331 Fax 770 487 3360 NOTE Toexpediteassistance allcorrespondence communicationMUST includethefollowing information Model Number Serial Number Completeanddetailedexplanationoftheproblem 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 concerns wh...

Page 3: ...MWF Water cooled 12 c KM 900MRF Remote air cooled 13 d KM 900MRF3 Remote air cooled 3 phase 14 2 CONTROLLER BOARD 15 a SOLID STATE CONTROL 15 b CONTROLLER BOARD 15 c SEQUENCE 19 d CONTROLS AND ADJUSTMENTS 22 e CHECKING CONTROLLER BOARD 25 III TECHNICAL INFORMATION 27 1 WATER CIRCUIT AND REFRIGERANT CIRCUIT 27 a KM 900MAF Air cooled 27 b KM 900MWF Water cooled 28 c KM 900MRF Remote air cooled and K...

Page 4: ...7 REMOVAL AND REPLACEMENT OF EVAPORATOR 52 8 REMOVAL AND REPLACEMENT OF WATER REGULATING VALVE WATER COOLED MODEL ONLY 53 9 ADJUSTMENT OF WATER REGULATING VALVE WATER COOLED MODEL ONLY 54 10 REMOVAL AND REPLACEMENT OF CONDENSING PRESSURE REGULATOR C P R REMOTE AIR COOLED MODEL ONLY 55 11 REMOVAL AND REPLACEMENT OF THERMISTOR 56 12 REMOVAL AND REPLACEMENT OF FAN MOTOR 57 13 REMOVAL AND REPLACEMENT ...

Page 5: ...5 I SPECIFICATIONS 1 KM 900MAF We reserve the right to make changes in specifications and design without prior notice ...

Page 6: ...6 2 KM 900MWF We reserve the right to make changes in specifications and design without prior notice ...

Page 7: ...7 3 KM 900MRF We reserve the right to make changes in specifications and design without prior notice ...

Page 8: ...8 4 KM 900MRF3 We reserve the right to make changes in specifications and design without prior notice ...

Page 9: ...9 5 CONDENSING UNIT URC 12F ...

Page 10: ...CTRICAL CONDENSER HEAD PRESSURE CONTROL AMBIENT CONDITION Galvanized Steel 35 11 16 x 15 11 16 x 21 15 16 907 2 x 398 x 557 8 mm R404A 4 lbs 7 oz 2000 g Net 80 lbs 36 kg Shipping 87 lbs 39 kg One Shot Couplings Aeroquip Permanent Connection Air cooled Condensing Pressure Regulator Min 20 F Max 122 F 29 C to 50 C Outdoor use ...

Page 11: ...11 II GENERAL INFORMATION 1 CONSTRUCTION a KM 900MAF ...

Page 12: ...12 b KM 900MWF ...

Page 13: ...13 c KM 900MRF ...

Page 14: ...14 d KM 900MRF3 ...

Page 15: ...placing the 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 PAR...

Page 16: ...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 17: ...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 18: ...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 19: ...st 5 minutes in freeze cycle Ready to complete freeze cycle when Float Switch circuit opens 4 Defrost Timer stops counting Defrost cycle is completed and freeze cycle starts 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 time is li...

Page 20: ...ANT Water 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 and freeze cycle starts IMPORTANT Board never accepts freeze completion signal within the first 5 minutes in freeze cycle IMPORTANT 1 Board never accepts defrost completion signal within ...

Page 21: ... minutes 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 and freeze cycle starts 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 ...

Page 22: ...umes operation in 2 seconds Then the Pump Motor drains the Water Tank for the time determined by the Drain Timer The Drain Timer also 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 ...

Page 23: ... the connector K3 on the board ii Remove the Thermistor See V 11 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 24: ...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 25: ...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 26: ...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 27: ...27 III TECHNICAL INFORMATION 1 WATER CIRCUIT AND REFRIGERANT CIRCUIT a KM 900MAF ...

Page 28: ...28 b KM 900MWF ...

Page 29: ...29 c KM 900MRF and KM 900MRF3 ...

Page 30: ...30 2 WIRING DIAGRAMS a KM 900MAF Note Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 ...

Page 31: ...31 b KM 900MWF Note Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 ...

Page 32: ...32 c KM 900MRF Note Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 ...

Page 33: ...33 d KM 900MRF3 Note Pressure Switch Cut out 412 PSIG Cut in 327 21 PSIG 21 0 ...

Page 34: ...r Max Min 60 min 5 min Min Max Max 2 min 6 min 6 min Max 20 min Time Up 60 sec If Float Sw is OFF From Defrost Cycle When Control Sw is turned OFF Pressure Sw is OFF or Thermistor Temp exceeds t1 To Defrost Cycle 1 1 2 KM 1200SAE50 3 KM SRE50 Note The icemaker does not complete a defrost cycle in the first 2 or 3 minutes See II 2 d CONTROLS AND ADJUSTMENTS ...

Page 35: ...reeze Cycle Control Sw in WASH Min Max Max 3 min 6 min 6 min Max 20 min 1 The 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 3 4 KM 1200SAE50 2 2 1 KM 1200SRE50 ...

Page 36: ...ATA a KM 900MAF 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 37: ...900MWF 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 38: ...900MRF 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 39: ...00MRF3 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 40: ...ty 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 AND ADJUSTMENTS 1 Temperature Safety Defrost Control operates i Hot Gas Solenoid 1 Continues to open in 1 Check for power off in Valve free...

Page 41: ...mmended 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 overcharged or 3 Recharge undercharged 4 Line Valve continues to 4...

Page 42: ...place 5 Defective or bound impeller 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 F...

Page 43: ... get does not fall recommended pressure into bin in c Water Solenoid 1 Dirty mesh filter or orifice 1 Clean harvest cycle Valve 2 Diaphragm does not close 2 Check for water leaks with icemaker off d Ambient and or 1 Too cool 1 Increase temperature water temperature e Line Valve 1 Continues to open in 1 Check operation in harvest cycle harvest cycle and replace f Thermistor 1 Out of position or loo...

Page 44: ... touch lines or other 1 Replace surfaces 3 Ice in storage a Bin Drain 1 Plugged 1 Clean bin often melts PROBLEM POSSIBLE CAUSE REMEDY 1 Small Cube a Ice Cube Guide 1 Out of position 1 Place in position Circulated water falls into bin b See chart 1 5 and check water supply line Water Solenoid Valve water system Pump Motor or Controller Board c Drain Valve 1 Dirty 1 Clean 2 Cloudy or a See chart 2 1...

Page 45: ...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 atmo sphere 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 46: ... Hoses and Service Mani fold 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 decomposed to form hydrofluoric acid and carbonyl fluoride both of which are h...

Page 47: ...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 48: ...dels see the Nameplate for the required refrigerant charge For remote air cooled models see the Charge Label in the machine compartment 16 Connect the Terminals and replace the Terminal Cover in its correct position 17 Replace the panels in their correct positions 18 Turn on the power supply ...

Page 49: ...ks using nitrogen gas 140 PSIG and soap bubbles 7 Evacuate the system and charge it with refrigerant For air cooled and water cooled models see the Nameplate for the required refrigerant charge For remote air cooled models see the Charge Label in the machine compartment 8 Replace the panels in their correct positions 9 Turn on the power supply 5 REMOVAL AND REPLACEMENT OF EXPANSION VALVE IMPORTANT...

Page 50: ...aks using nitrogen gas 140 PSIG and soap bubbles 9 Evacuate the system and charge it with refrigerant For air cooled and water cooled models see the Nameplate for the required refrigerant charge For remote air cooled models see the Charge Label in the machine compartment 10 Attach the Bulb to the suction line in position Be sure to secure it with clamps and to insulate it 11 Place the new set of E...

Page 51: ... 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 For air cooled and water cooled models see the Nameplate for the required refrigerant charge For remote air cooled models see the Charge Label in the machine compartment 10...

Page 52: ...sis 5 Remove the Insulation Tube and disconnect the Evaporator Inlet Tubing at the Tee next 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 PSIG and soap bubbles 10 Evacuate the system and charge it with refrigerant For air cooled and water cooled models see the...

Page 53: ...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 54: ...he system Or prepare a thermometer to check for the condenser 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 ...

Page 55: ...k off the stub on the dome to release the dome charge 5 Disconnect the C P R using brazing equipment 6 Install the new C P R Use nitrogen gas at the pressure of 3 4 PSIG when brazing the C P R WARNING Always protect the C P R body by using a damp cloth to prevent the C P R from overheating Do not braze with the C P R body exceeding 250 F 7 Install the new Drier in the icemaker 8 Check for leaks us...

Page 56: ...rd 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 the Thermistor Holder concave 9 Attach the new Thermistor to the Suction Pipe very carefull...

Page 57: ...te 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 Junction Box Cover from the remote condenser unit Remote Air cooled model 4 Remove the closed end connectors from the Fan Motor leads 5 Remove the Fan Motor Bracket and Fan Motor 6 Install the new Fan Motor and replace the removed par...

Page 58: ...e and replace 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 Front Panel in its correct position 14 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 Tubin...

Page 59: ...d check for leaks 14 Replace the Base Cover 15 Replace the Front Panel in its correct position 15 REMOVAL AND REPLACEMENT OF SPRAY TUBES 1 Turn off the power supply 2 Remove the Front Panel and the Insulation Panel 3 Remove the Rubber Hoses from the Spray Tubes Water Supply Pipe 4 Release the Clamps and disconnect the Rubber Hoses 5 Remove the Spray Tubes by squeezing the side tabs 6 Install the n...

Page 60: ...ee days 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 ice...

Page 61: ...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 4 4 Replace the removed parts in t...

Page 62: ...monia 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 operation The Compressor will no...

Page 63: ...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 and start the washing process 13 Turn off the power...

Page 64: ...en you proceed to b SANITIZING PROCEDURE 29 Repeat the above steps 17 through 28 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 Insulation Panel if ...

Page 65: ...truction 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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