Hoshizaki KM-280MAH-E Service Manual Download

Page: 44 / 63

Problem

Possible Cause

Remedy

[5]

d) Pump Motor

1. Motor winding opened.

1. Replace.

2. Bearing worn out.

2. Replace.

3. Wiring to pump motor.

3. Check for loose

connection or open, and
replace.

4. Defective capacitor.

4. Replace.

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.C.5. Checking

the Controller Board."

[6]

a) Fan Motor

1. Motor winding opened.

1. Replace.

2. Bearing worn out.

2. Replace.

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 replace.

b) Controller Board

1. Defective.

1. See "II.C.5. Checking

the Controller Board."

[7]

a) Refrigerant

1. Undercharged.

1. Check for leaks and

recharge.

2. Air or moisture trapped. 2. Replace drier and

recharge.

b) Compressor

1. Defective valve.

1. Replace.

c) Hot Gas Solenoid

Valve

1. Continues to open in

freeze cycle.

1. Check and replace.

Fan motor will not

start, or is not
operating.

All components run,

but no ice is
produced.

Continued from
previous page.

Summary of Contents for KM-280MAH-E

Page 1: ...SERVICE MANUAL MODULAR CRESCENT CUBER FOR QUALIFIED SERVICE PERSON 89 336 73 23 HOSHIZAKI NUMBER 73125 ISSUED December17 2004 KM 280MAH E KM 500MAH E KM 630MAH E ...

Page 2: ...many TEL 49 0 215492810 FAX 49 0 2154928128 France TEL 33 0 148137130 FAX 33 0 148130992 Note To expedite assistance all correspondence communication MUST include the following 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 ...

Page 3: ...1 Solid State Control 14 2 Controller Board 14 3 Sequence 19 4 Controls and Adjustments 22 5 Checking the Controller Board 25 D Mechanical Bin Control 26 1 Proximity Switch 26 2 Explanation of Operation 26 3 Troubleshooting Mechanical Bin Control Only 27 III Technical Information 28 A Water Circuit and Refrigerant Circuit 28 1 KM 280MAH E 28 2 KM 500MAH E KM 630MAH E 29 B Wiring Diagrams 30 1a KM ...

Page 4: ...Removal and Replacement of Hot Gas Valve 52 G Removal and Replacement of Evaporator 53 H Removal and Replacement of Thermistor 54 I Removal and Replacement of Fan Motor 55 J Removal and Replacement of Water Valve 56 K Removal and Replacement of Pump Motor 56 L Removal and Replacement of Float Switch 57 M Removal and Replacement of Spray Tubes 58 N Removal and Replacement of Transformer 58 VI Clean...

Page 5: ...el Galvanized Steel Rear WEIGHT Net 151 lbs 69 kg Shipping 175 lbs 80 kg CONNECTIONS ELECTRIC Cord Connection WATER SUPPLY Inlet 1 2 FPT DRAIN Outlet 3 4 FPT 3 8 OD Pipe CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water Thermistor and Timer ICE MAKING WATER CONTROL Timer Controlled Overflow Pipe COOLING WATER CONTROL N A BIN CONTROL SYSTEM Thermostat COMPRESSOR Hermetic ...

Page 6: ...EXTERIOR FINISH Stainless Steel Galvanized Steel Rear WEIGHT Net 146 lbs 66 kg Shipping 170 lbs 77 kg CONNECTIONS ELECTRIC Cord Connection WATER SUPPLY Inlet 1 2 FPT DRAIN Outlet 3 4 FPT 3 8 OD Pipe CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water Thermistor and Timer ICE MAKING WATER CONTROL Timer Controlled Overflow Pipe COOLING WATER CONTROL N A BIN CONTROL SYSTEM Th...

Page 7: ...RIOR FINISH Stainless Steel Galvanized Steel Rear WEIGHT Net 165 lbs 75 kg Shipping 185 lbs 84 kg CONNECTIONS ELECTRIC Permanent Connection WATER SUPPLY Inlet 1 2 FPT DRAIN Outlet 3 4 FPT 3 8 OD Pipe CUBE CONTROL SYSTEM Float Switch HARVESTING CONTROL SYSTEM Hot Gas and Water Thermistor and Timer ICE MAKING WATER CONTROL Timer Controlled Overflow Pipe COOLING WATER CONTROL N A BIN CONTROL SYSTEM T...

Page 8: ...8 II General Information A Dimensions 1 KM 280MAH E ...

Page 9: ...9 2 KM 500MAH E ...

Page 10: ...10 3 KM 630MAH E ...

Page 11: ...et Control Switch Condenser Hot Gas Valve Expansion Valve Fan Motor Condenser Compressor Drier Float Switch Control Box Water Pump Transformer Bin Control Thermostat except models with Mechanical Bin Control Mechanical Bin Control except models with Thermostat ...

Page 12: ...rol Switch Condenser Hot Gas Valve Expansion Valve Fan Motor Condenser Compressor Drier Float Switch Control Box Water Pump Transformer Bin Control Thermostat except models with Mechanical Bin Control Mechanical Bin Control except models with Thermostat ...

Page 13: ...rol Switch Condenser Hot Gas Valve Expansion Valve Fan Motor Condenser Compressor Drier Float Switch Control Box Water Pump Bin Control Thermostat except models with Mechanical Bin Control Mechanical Bin Control except models with Thermostat Transformer ...

Page 14: ...tor white float switch black and mechanical bin control red For machines with thermostat there is no connection on K4 5 Always replace the whole board assembly when it goes bad 6 Do not short out power supply to test for voltage Features of Control Products E Controller Board a Maximum Water Supply Period 6 minutes Water solenoid valve opening in the defrost harvest cycle is limited by the defrost...

Page 15: ...ks 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 making cycle If the float switch is in the down position electrical circuit open the controller board changes to a one minute water fill cycle before starting the ic...

Page 16: ...k for open thermistor HGV not opening TXV leaking by low charge or inefficient compressor 3 Freeze Backup Timer freeze 60 min Yellow LED marked 60 MIN lights up Check for F S stuck closed up WV leaking by HGV leaking by TXV not feeding properly low charge or inefficient compressor 4 Short Circuit machines with mechanical bin control ONLY Short circuit between the K4 connection on the control board...

Page 17: ...rmal operation The application switch located between relay X3 X4 must be set to match the original board application Place this switch in the ALP position if there is no white wire supplied to the K1 connector If there is a white wire place the switch in the C position If this switch is placed in the wrong position either the compressor contactor will remain energized with the control switch OFF ...

Page 18: ...18 Control Products HOS 001A Board ...

Page 19: ...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 limited to 20 minutes even if defrost timer does not sto...

Page 20: ...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 limited to 20 minutes even if defrost timer does not stop counting IMPORTANT Water valve openi...

Page 21: ...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 limited to 20 minutes even if defrost timer does not stop counting IMPORTANT Water valve opening is limited to 6 minutes IMPORTANT Fr...

Page 22: ...ter The pump motor drains the water tank at the frequency determined by the drain counter Switch No 7 Used only on models with mechanical bin control Should be ON for models with mechanical bin control and OFF for models with bin thermostat Switch No 8 Used only for checking the controller board Usually OFF Dip Switch No 1 2 3 4 5 6 7 8 9 10 KM 280MAH E ON OFF OFF OFF OFF OFF ON OFF ON OFF KM 500M...

Page 23: ...oval and Replacement of 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 kΩ Replace the thermistor if it exceeds the normal reading b Defrost Timer No adjustment is required under normal use as the defrost timer is adjusted to the suitable position However if...

Page 24: ... drain the water tank T2 Time to restrain defrost completion d 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...

Page 25: ...fter ice contacts the bin control thermostat bulb 2 Models with Mechanical Bin Control CAUTION Dip switch no 7 must be set to the ON position If no 7 is set to the OFF position the machine will run continuously causing a freeze up condition No adjustment is required The bin control is factory adjusted 5 Checking the Controller Board 1 Visually check the sequence with the icemaker operating 2 Visua...

Page 26: ...put test switch S3 provides a relay sequence test 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 D Mechanical Bin Control These instructions are not applicable to models with thermostat 1 Proximity Switch This machine uses a lever actuated proximi...

Page 27: ...removed and the wires are connected properly 3 Check to make sure no obstruction prevents the lever from moving to the bin empty position b Machine will not shut off 1 Refer to Section IV Service Diagnosis to verify that non bin control related issues are resolved 2 Dip switch No 7 should be in the on position If the switch is in the off position the controller board will not receive input from th...

Page 28: ...28 III Technical Information A Water Circuit and Refrigerant Circuit 1 KM 280MAH E ...

Page 29: ...29 2 KM 500MAH E KM 630MAH E ...

Page 30: ...30 B Wiring Diagrams 1a KM 280MAH E auxiliary codes L 0 through M 1 Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 31: ...31 1b KM 280MAH E auxiliary codes M 2 and later Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 32: ...32 2a KM 500MAH E auxiliary codes L 0 through M 1 Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 33: ...33 2b KM 500MAH E auxiliary codes M 2 and later Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 34: ...34 3a KM 630MAH E auxiliary codes L 0 through M 1 Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 35: ...35 3b KM 630MAH E auxiliary codes M 2 and later Pressure Switch Cut out 412 psig 28 4 bar Cut in 327 21 psig 22 5 1 5 bar 21 0 1 5 0 ...

Page 36: ...chanical Bin Control Only The bin control will only shut off the ice machine during the first five minutes of the freeze cycle 2Theicemakerdoesnotcompleteadefrostcycleinthefirst2or3minutes See II C 4 Controlsand Adjustments ...

Page 37: ...e machine during the first five minutes of the freeze cycle 2 The pump motor waits for 2 seconds before starting a drain cycle See II C 4 Controls and Adjustments 3 The icemaker does not complete a defrost cycle in the first 2 or 3 minutes See II C 4 Controls and Adjustments ...

Page 38: ...2 min 100 38 70 21 80 27 90 32 min 100 38 70 21 245 17 2 267 18 8 290 20 4 80 27 262 18 4 296 20 8 315 22 1 90 32 267 18 8 320 22 5 341 24 0 PSIG kg cm2 G 100 38 269 18 9 325 22 8 360 25 3 70 21 55 3 9 58 4 1 61 4 3 80 27 57 4 0 62 4 3 64 4 5 90 32 58 4 1 65 4 6 68 4 8 PSIG kg cm2 G 100 38 58 4 1 66 4 6 70 4 9 3 1 3 0 2 9 20 22 23 28 30 35 WATER TEMP ºF ºC AMBIENT TEMP ºF ºC 50 10 70 21 90 32 763 ...

Page 39: ...27 90 32 min 100 38 70 21 80 27 90 32 min 100 38 70 21 250 17 6 268 18 8 293 20 6 80 27 263 18 5 291 20 4 316 22 3 90 32 268 18 8 310 21 8 336 23 6 PSIG kg cm2 G 100 38 273 19 2 316 22 2 360 25 3 70 21 50 3 5 53 3 7 55 3 8 80 27 52 3 7 56 3 9 57 4 0 90 32 53 3 7 59 4 1 61 4 3 PSIG kg cm2 G 100 38 53 3 7 59 4 2 62 4 4 3 3 3 1 2 9 29 31 32 36 37 41 WATER TEMP F C AMBIENT TEMP F C 50 10 70 21 90 32 9...

Page 40: ... 80 27 90 32 min 100 38 70 21 80 27 90 32 min 100 38 70 21 270 19 0 291 20 4 309 21 7 80 27 286 20 1 318 22 3 330 23 2 90 32 291 20 4 340 23 9 356 25 0 PSIG kg cm2 G 100 38 291 20 5 344 24 2 370 26 0 70 21 50 3 5 51 3 6 52 3 7 80 27 50 3 5 51 3 6 53 3 7 90 32 51 3 6 52 3 7 54 3 8 PSIG kg cm2 G 100 38 51 3 6 52 3 7 55 3 9 3 3 2 9 32 35 35 40 42 47 WATER TEMP F C AMBIENT TEMP F C 50 10 70 21 90 32 1...

Page 41: ... warm 3 See II C 4 Controls and Adjustments f Bin Control 4 Bulb out of position 4 Place in position 5 Bad contacts or leaks in bulb 5 Check for continuity and replace e High Pressure Control 1 Bad contacts 1 Check for continuity and replace f Transformer 1 Thermal fuse blown or coil winding opened 1 Replace g Wiring to Controller Board 1 Loose connections or open 1 Check for continuity and replac...

Page 42: ...ce l Controller Board 1 Defective 1 See II C 5 Checking the Controller Board 2 a Float Switch 1 Connector disconnected 1 Place in position 2 Leads opened or defective switch 2 Check and replace 3 Float does not move freely 3 Clean or replace b Controller Board 1 Defective 1 Replace 3 a Wash Switch 1 WASH position 1 Move to ICE position 2 Bad contacts 2 Check and replace b High Pressure Control 1 D...

Page 43: ...ace 2 Defective 2 Replace 3 Protector tripped 3 Reduce temperature h Controller Board 1 Defective 1 See II C 5 Checking the Controller Board 4 a Water Solenoid Valve 1 Diaphragm does not close 1 Check for water leaks with icemaker off b Controller Board 1 Defective 1 See II C 5 Checking the Controller Board 5 a Water Supply Line 1 Water pressure too low and water level in water tank too low 1 Chec...

Page 44: ... opened 1 Replace 2 Bearing worn out 2 Replace 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 replace b Controller Board 1 Defective 1 See II C 5 Checking the Controller Board 7 a Refrigerant 1 Undercharged 1 Check for leaks and recharge 2 Air or moisture trapped 2 Replace drier and recharge b Compressor 1 Defect...

Page 45: ... attachment 1 See V H Removal and Replacement of Thermistor g Controller Board 1 Defrost timer is set too short 1 Adjust longer referring to II C 4 Controls and Adjustments b Defrost Timer 2 Defective 2 See II C 5 Checking the Controller Board 3 Other a Spray Tubes 1 Clogged 1 Clean 2 Out of position 2 Place in position b Water System 1 Dirty 1 Clean c Refrigerant 1 Undercharged 1 Check for leaks ...

Page 46: ...hart A 5 and check water supply line water solenoid valve water system pump motor and controller board See chart B 1 and B 3 and check float switch water solenoid valve controller board spray tubes water system refrigerant charge and expansion valve Problem Possible Cause Remedy 1 a 1 Set too cold 1 Adjust warmer 2 Defective 2 Replace 2 Abnormal noise a Pump Motor 1 Bearings worn out 1 Replace b F...

Page 47: ...ne 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 2 Evacuation and Recharge R 404A 1 Attach charging hoses a service manifold and a vacuum pump to the system If possible use quick release connectors on the access valves especially the high side IMPORTA...

Page 48: ...he hoses and service manifold 10 Cap the access valves to prevent a possible leak B Brazing DANGER 1 Refrigerant R 404A itself is not flammable at atmospheric pressure and temperatures up to 80 C 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 49: ...erant Recovery 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 Attach the rubber grommets of the prior compressor 9 Sandpaper the suction discharg...

Page 50: ...aker 2 Remove the panels 3 Recover the refrigerant and store it in an approved container See V A 1 Refrigerant Recovery 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 a pressure of 3 to 4 psig 21 to 28 bar when brazing the tubings 6 Check for leaks using nitrogen gas at 140 psig 9 65 bar and soap bubbles 7 Evacuat...

Page 51: ...nt components from excessive heat using damp cloths or similar 6 Braze the new expansion valve with nitrogen gas flowing at a pressure of 3 to 4 psig 21 to 28 bar WARNING 1 Do not heat the wall Place a steel barrier for protection 2 Always protect the valve body by using a damp cloth to prevent the valve from overheating Do not braze with the valve body exceeding 121 C 7 Install the new drier 8 Ch...

Page 52: ...Disconnect the hot gas valve or line valve using brazing equipment 6 Install the new valve with nitrogen gas flowing at a pressure of 3 to 4 psig 21 to 28 bar 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 121 C 7 Install the new drier 8 Check for leaks using nitrogen gas at 140 psig 9 65 bar and soap bub...

Page 53: ...ubings go through the chassis 5 Remove the insulation tube and disconnect the evaporator inlet tubing at the tee next to the expansion valve using brazing equipment Protect the valve from excessive heat 6 Lift up the evaporator and disconnect the evaporator outlet tubing 7 Install the new evaporator with nitrogen gas flowing at a pressure of 3 to 4 psig 21 to 28 bar 8 Install the new drier 9 Check...

Page 54: ...ermistor See Fig 1 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 carefully to prevent damage to the leads Secure it using the thermistor holder and ...

Page 55: ...he power supply Unplug the icemaker 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 reverse order of which they were removed 6 Replace the panels in their correct positions 7 Plug in the icemaker Turn on the power supply ...

Page 56: ...line shut off valve 10 Plug in the icemaker Turn on the power supply 11 Check for leaks 12 Replace the top and front panels in their correct positions K Removal and Replacement of Pump Motor Note When replacing a pump motor with defective winding it is recommended that a new capacitor be installed 1 Turn off the power supply Unplug the icemaker 2 Remove the front panel 3 Remove the base cover 4 Dr...

Page 57: ...ront panel 3 Remove the base cover 4 Drain the water tank by removing one end of the pump tubing See Fig 3 Refit the hose back into position 5 Remove the black rubber connector from the base of the float switch 6 Remove the screws securing the float switch bracket and the stainless steel adjusting guide 7 Take off the hose sleeving the float switch leads 8 Sleeve the leads of the new float switch ...

Page 58: ... the removed parts in the reverse order of which they were removed 7 Replace the panels in their correct positions 8 Plug in the icemaker Turn on the power supply N Removal and Replacement of Transformer 1 Turn off the power supply Unplug the icemaker 2 Remove the panels 3 Remove the closed end connectors from the transformer leads 4 Remove the transformer cover 5 Remove the transformer 6 Install ...

Page 59: ... two or three days it is sufficient to only move the control switch to the OFF position unless the icemaker will be at sub freezing temperatures 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 When all the ice from the previous ice making cycle has defrosted from the evaporator approximately ...

Page 60: ...ended cleaners and sanitizers 5 Never mix cleaning and sanitizing solutions in an attempt to shorten cleaning time 6 Wipe off any splashed or spilt cleaner sanitizer immediately 1 Cleaning Procedure 1 Mix 3 gallons 11 4 l of water with Hoshizaki Scale Away or LIME A WAY Economics Laboratory Inc or Hoshizaki Cleaner Rector Seal Corp using a mixing rate as recommended on the package 2 Remove all ice...

Page 61: ...upply to fill the water tank with water 19 Turn off the power supply after 3 minutes 20 Remove the front panel 21 Move the control switch to the WASH position 22 Refit the front panel in its correct position 23 Turn on the power supply to rinse off the cleaning solution 24 Turn off the power supply after 5 minutes 25 Remove the front panel 26 Drain the water tank by removing one end of the pump tu...

Page 62: ...ol switch is in the WASH position 5 Turn on the power supply and start the sanitizing process 6 Turn off the power supply after 15 minutes 7 Remove the front panel 8 Drain the water tank See step 6 in 1 Cleaning Procedure 9 Refit the pump tubing in its correct position 10 Repeat the above steps 16 through 27 in 1 Cleaning Procedure two times to rinse thoroughly 11 Move the control switch to the IC...

Page 63: ...re anything else in the bin Keep the scoop clean Clean it by using a neutral cleaner and rinse thoroughly Clean the bin liner by using a neutral cleaner Rinse thoroughly after cleaning 3 Air Filter A plastic mesh air filter removes dirt or dust from the air and keeps the condenser from getting clogged As the filter becomes clogged the icemaker s performance will be reduced Check the filter at leas...

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