Hoshizaki KML-451MAH Service Manual Download

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Hoshizaki

“A Superior Degree

of Reliability”

www.hoshizaki.com

Models

KML-451MAH
KML-451MWH

Low-Profile Modular Crescent Cuber

Hoshizaki America, Inc.

SERVICE MANUAL

™

Number: 73143

Issued: 3-1-2007

Summary of Contents for KML-451MAH

Page 1: ...Hoshizaki A Superior Degree of Reliability www hoshizaki com Models KML 451MAH KML 451MWH Low Profile Modular Crescent Cuber Hoshizaki America Inc SERVICE MANUAL Number 73143 Issued 3 1 2007 ...

Page 2: ... which have not been satisfactorily addressed please call write or send an e mail message to the HOSHIZAKI Technical Support Department for assistance HOSHIZAKI AMERICA INC 618 Highway 74 South Peachtree City GA 30269 Attn HOSHIZAKI Technical Support Department Phone 1 800 233 1940 Technical Service 770 487 2331 Fax 1 800 843 1056 770 487 3360 E mail techsupport hoshizaki com Web Site www hoshizak...

Page 3: ... 3 Freeze Cycle 9 4 Pump Out Cycle 9 5 Normal Harvest Cycle 9 C Control Board 11 1 Control Board Layout 12 2 Features 13 a Maximum Water Supply Period 6 minutes 13 b Harvest Backup Timer and Freeze Timer 13 c High Temperature Safety 13 d Low Water Safety 13 e High Voltage and Low Voltage Cut outs 13 f LED Lights and Audible Alarm Safeties 14 3 Controls and Adjustments 15 a Default Dip Switch Setti...

Page 4: ...l and Replacement of Compressor 35 C Removal and Replacement of Expansion Valve 36 D Removal and Replacement of Hot Gas Valve or Line Valve 36 E Removal and Replacement of Evaporator 37 F Removal and Replacement of Water Regulating Valve Water Cooled Model Only 38 G Adjustment of Water Regulating Valve Water Cooled Model Only 39 H Removal and Replacement of Headmaster Condensing Pressure Regulator...

Page 5: ...t Connection WATER SUPPLY Inlet 1 2 FPT DRAIN Outlet 3 4 FPT 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 Model RS43C2E CAA 219 CONDENSER Air Cooled Fin and tube type EVAPORATOR Vertical type Stainless Steel and Cop...

Page 6: ...WEIGHT Net 154 lbs 70 kg Shipping 185 lbs 84 kg CONNECTIONS ELECTRIC Permanent Connection WATER SUPPLY Inlet 1 2 FPT Condenser Inlet 1 2 FPT DRAIN Outlet 3 4 FPT Condenser Outlet 3 8 FPT 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 Water Regulator BIN CONTROL SYSTEM Th...

Page 7: ...AH air cooled Spray Tubes Water Supply Inlet Junction Box Condenser Condenser Fan Motor Control Box Drier Hot Gas Valve Compressor Float Switch Water Pump Bin Control Thermostat Control Switches Expansion Valve Inlet Water Valve Drain Valve Wash Valve ...

Page 8: ...ter Regulator Water Supply Inlet Junction Box Condenser Control Box Drier Hot Gas Valve Compressor Float Switch Water Pump Bin Control Thermostat Control Switches Expansion Valve Spray Tubes Drain Valve Wash Valve Inlet Water Valve ...

Page 9: ...ycle starts For the first 5 minutes the control board will not accept a signal from F S This 5 minute minimum freeze acts as a short cycle protection At the end of 5 minutes F S assumes control As ice builds on the evaporator the water level in the sump lowers The freeze continues until F S opens and terminates ice production 4 Pump Out Cycle LEDs 1 3 and 2 are on Comp and FMR continue to run HGV ...

Page 10: ...timer in control F S in control Initial startup always begins here E board will have 5 second delay If F S is open compressor stops and cycle returns to 1 minute fill Legend Comp compressor DV drain valve FMR remote fan motor FMS self contained fan motor F S float switch HGV hot gas valve LLV liquid line valve PM pump motor SR service relay WV inlet water valve Components Energized when the Contro...

Page 11: ... to static discharge It is especially important to touch the metal part of the unit when handling or replacing 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 re...

Page 12: ...l 8 Open Switch for C board and ALPINE board service boards only Alarm Reset Switch Backup Freeze Timer LED Dip Switch Backup Harvest Timer LED Alarm Buzzer Power LED lights when power is supplied to the board Relay LEDs 4 indicate which relays are energized as listed below LED 2 Hot Gas Valve HGV Self Contained Fan Motor FMS FMS off when LED on LED 3 Pump Motor PM on at pump out only LED 4 Water ...

Page 13: ...rol board must be pressed with power on to reset the safety d Low Water Safety The control 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 harvest cycle If the float switch is in the up position electrical circuit closed the control board changes to the next cycle If the float switch is in the down position electrical circu...

Page 14: ...rm Notes 1 High Evaporator Temp temperature 127 F 53 C Check for harvest problem stuck HGV or relay hot water entering unit stuck HM or shorted thermistor 2 Harvest Backup Timer harvest 20 min for two cycles in a row Orange LED marked H TIMER lights up Check for open thermistor HGV not opening TXV leaking by low charge or inefficient compressor 3 Freeze Timer freeze specified setting for two cycle...

Page 15: ...arts counting when the thermistor reads 48 F 9 C at the evaporator outlet No adjustment is required under normal use as the harvest timer is adjusted to the suitable position However a setting longer than the factory setting may be advised in cases where the flush provided at harvest needs to be prolonged for extra cleaning Before changing this setting call the HOSHIZAKI Technical Support Departme...

Page 16: ...ter tank T2 Harvest timer at pump out Pump out always occurs on the 2nd harvest after startup Then depending on the pump out frequency control setting dip switch 5 6 pump out occurs every cycle or every 2nd 5th or 10th cycle d Pump Out Frequency Control dip switch 5 6 The pump motor drains the water tank at the frequency set by the pump out frequency control The pump out frequency control is facto...

Page 17: ...eck the brown wire at pin 10 to a white neutral wire for 115 volts Always choose a white neutral wire to establish a good neutral connection when checking voltages A jumper also feeds 115 volts into pin 7 If no voltage is present check the 115 volt supply circuit 4 The output test switch provides a relay sequence test Make sure the control switch is in the ICE position then press the output test s...

Page 18: ...ermistor leads Normal reading is within 3 5 to 7 kΩ Replace the thermistor if it exceeds the normal reading E Bin Control CAUTION When the ambient temperature is below 45 F 7 C the bin control thermostat operates to stop the icemaker even if the ice storage bin is empty When the thermostat is set in the prohibited range the icemaker operates continuously even if the ice storage bin is filled with ...

Page 19: ...any position a DRAIN The KML series utilizes a pump out drain system When the service switch is active and placed in the DRAIN position power is supplied to the pump and drain valve b CIRCULATE When the service switch is active and placed in the CIRCULATE position power is supplied to the pump only This operation can be used to circulate cleaner for extended periods of time over the outside surfac...

Page 20: ...20 III Technical Information A Water Circuit and Refrigeration Circuit 1 KML 451MAH air cooled ...

Page 21: ...21 2 KML 451MWH water cooled ...

Page 22: ...B Wiring Diagrams 1 KML 451MAH air cooled and KML 451MWH water cooled Pressure Switch Air Cooled Model Water Cooled Model Cut out 412 21 3 PSIG 384 21 3 PSIG Cut in 327 21 3 PSIG 284 21 3 PSIG 0 0 12V WASH ...

Page 23: ...70 21 42 3 0 45 3 2 51 3 6 80 27 44 3 1 49 3 5 55 3 9 90 32 45 3 2 53 3 7 59 4 1 PSIG kg cm2 G 100 38 47 3 3 54 3 8 64 4 5 23 23 25 2 7 4 0 3 2 3 6 3 1 2 7 3 7 21 APPROXIMATE ICE PRODUCTION PER 24 HR APPROXIMATE ELECTRIC CONSUMPTION APPROXIMATE WATER CONSUMPTION PER 24 HR FREEZING CYCLE TIME WATER TEMP ºF ºC AMBIENT TEMP ºF ºC 50 10 70 21 90 32 917 913 944 970 976 890 908 913 25 28 30 32 941 969 9...

Page 24: ... 3 261 18 3 271 19 1 90 32 260 18 3 261 18 4 270 19 0 PSIG kg cm 2 G 100 38 264 18 6 263 18 5 278 19 5 70 21 44 3 1 45 3 1 48 3 4 80 27 44 3 1 46 3 2 50 3 5 90 32 45 3 1 47 3 3 51 3 6 PSIG kg cm 2 G 100 38 46 3 2 48 3 4 55 3 8 TOTAL HEAT OF REJECTION FROM COMPRESSOR 1 100 BTU h AT 90ºF 32ºC WT 70ºF 21ºC WATER FLOW FOR CONDENSER 48 gal h AT 100ºF 38ºC WT 90ºF 32ºC PRESSURE DROP OF COOLING WATER LIN...

Page 25: ... condenser unit and the hot gas valve energizes The evaporator warms and the thermistor senses 48 F 9 C The control board then receives the thermistor s 3 9 kΩ signal and turns operation of harvest over to the harvest timer The timer completes counting 1 to 3 minutes The unit then cycles to freeze Diagnosis Check if compressor is running hot gas valve is open water valve still open Average harvest...

Page 26: ...until bin control is satisfied or power is switched OFF The pump out cycle can be adjusted to occur every cycle or every 2 5 or 10 cycles The factory default is every 10 cycles The unit always restarts at the 1 minute fill cycle B Diagnostic Charts 1 No Ice Production Problem Possible Cause Remedy 1 The icemaker will not start a Power Supply 1 OFF position 1 Move to ON position 2 Loose connection ...

Page 27: ...ture or harvest backup timer safety operates 1 beep or 2 beep alarm 1 See II D Harvest Control Thermistor i Hot Gas Valve 1 Continues to open in freeze cycle and freeze timer safety operates 3 beep alarm 1 Check for hot gas valve stuck open and replace j Water Supply Line 1 Water supply off and water supply cycle does not finish 1 Check and get recommended pressure 2 Condenser water pressure too l...

Page 28: ...ect 3 Dirty condenser 3 Clean d Starter 1 Bad contacts 1 Check and replace 2 Coil winding opened 2 Replace e Compressor 1 Wiring to compressor 1 Check for loose connection or open and replace 2 Defective 2 Replace 3 Protector tripped 3 Reduce temperature f Control Board 1 No power to contactor 1 See II C 4 Control Board Check Procedure 4 Water continues to be supplied in freeze cycle a Inlet Water...

Page 29: ...rol Board Check Procedure 7 All components run but no ice is produced 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 Valve 1 Continues to open in freeze cycle 1 Check and replace d Line Valve if applicable 1 Continues to close in freeze cycle 1 Check and replace e Inlet Water Valv...

Page 30: ...ient and or water temperature 1 Too cool 1 Increase temperature f Line Valve if applicable 1 Continues to open in harvest cycle 1 Check operation in harvest cycle and replace g Thermistor 1 Out of position or loose attachment 1 See V I Removal and Replacement of Thermistor h Control Board 1 Harvest timer is set too short 1 Adjust longer referring to II C 3 Controls and Adjustments b Harvest Timer ...

Page 31: ...r valve line valve if applicable and hot gas valve 4 Abnormal Ice Problem Possible Cause Remedy 1 Small cubes a Ice Cube Guide 1 Out of position Circulated water falls into bin 1 Place in position b See chart 1 5 and check water supply line inlet water valve water system pump motor and control board c Drain Valve 1 Dirty 1 Clean 2 Cloudy or irregular cubes a See chart 2 1 and 2 3 and check float s...

Page 32: ...ion 2 Reinstall d Refrigerant Lines 1 Rub or touch other lines or surfaces 1 Replace 3 Ice in storage bin often melts a Drain Line s 1 Plugged 1 Clean b Icemaker and Bin 1 Drains not run separately 1 Separate the drain lines c Ice Cube Guide 1 Out of position Circulated water falls into bin 1 Place in position ...

Page 33: ...refrigerant access valves 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 Brazing WARNING 1 Refrigerant R 404A itself is not flammable at atmospheric pressure and temperatures up to 176 F 80 C 2 Refrigerant R 404A itself is not explosive or poisonous However when exposed t...

Page 34: ...n the vacuum pump to flow backward 3 Allow the vacuum pump to pull down to a 29 9 Hg vacuum Evacuating period depends on pump capacity 4 Close the low side valve and high side valve on the service manifold 5 Disconnect the vacuum pump and attach a refrigerant service cylinder to the high side line Remember to loosen the connection and purge the air from the hose For air cooled and water cooled mod...

Page 35: ... cover on the compressor and disconnect the compressor wiring 5 Remove the hold down bolts washers and rubber grommets 6 Remove the discharge and suction pipes 7 Remove the compressor Unpack the new compressor package 8 Attach the rubber grommets of the prior compressor 9 Place the compressor in position and secure it using the bolts and washers 10 Remove the drier then place the new drier in posi...

Page 36: ...alve body exceeding 250 F 121 C 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 rating label inside the icemaker 10 Attach the expansion valve bulb to the suction line in the same location as the previo...

Page 37: ...rge For remote air cooled models see the rating label inside the icemaker 11 Cut the leads of the solenoid allowing enough lead length to reconnect using closed end connectors 12 Connect the new solenoid leads 13 Attach the solenoid to the valve body and secure it with the screw 14 Replace the panels in their correct positions 15 Turn on the power supply E Removal and Replacement of Evaporator IMP...

Page 38: ...frigeration system is opened Do not replace the drier until after all other repair or replacement has been made 1 Turn off the power supply 2 Close the water supply line shut off valve 3 Remove the panels 4 Recover the refrigerant and store it in an approved container 5 Disconnect the capillary tube at the condenser outlet 6 Disconnect the flare connections of the valve 7 Remove the screws and the...

Page 39: ...e reference pressure is in the range indicated in the Head Pressure table in the Performance Data section If it is not in the proper range verify the refrigerant charge 3 Check that the condenser drain temperature is stable H Removal and Replacement of Headmaster Condensing Pressure Regulator C P R Remote Air Cooled Model Only IMPORTANT Always install a new drier every time the sealed refrigeratio...

Page 40: ...ement of Thermistor IMPORTANT 1 Fragile handle very carefully 2 Always use a recommended sealant high thermal conductive type Model KE4560RTV manufactured by SHINETSU SILICONE Part Code 60Y000 11 or Part Code 4A0683 01 or equivalent 3 Always use a recommended foam insulation non absorbent type or equivalent 4 Do not shorten or cut the thermistor leads when installing 1 Turn off the power supply 2 ...

Page 41: ...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 parts in the reverse order of which they were removed 7 Replace the panels in their correct positions 8 Replace the junction box cover in its correct position remote air cooled model 9 Turn on the power supply K Removal and Replacement of Water Valves 1 Tu...

Page 42: ...Remove the wiring connectors from the pump motor leads 5 Disconnect the hoses attached to the pump motor assembly 6 Remove the four screws and the pump motor 7 Install the new pump and replace the removed parts in the reverse order of which they were removed 8 Turn on the power supply and check for leaks 9 Replace the front panel in its correct position ...

Page 43: ... ice from the evaporator and the storage bin Note To remove cubes on the evaporator turn off the power supply and turn it on after 3 minutes The defrost cycle starts and the cubes will be removed from the evaporator 3 Turn off the power supply 4 Remove the front panel 5 Place the control switch in the SERVICE position Then place the service switch in the DRAIN position 6 Replace the front panel in...

Page 44: ...place the front panel in its correct position and turn on the power supply for 2 minutes 30 Turn off the power supply 31 Remove the front panel 32 Repeat steps 18 through 31 three more times to rinse thoroughly Note If you do not sanitize the icemaker go to step 14 in 2 Sanitizing Procedure 2 Sanitizing Procedure Following Cleaning Procedure 1 Dilute approximately 1 fl oz 30 ml of a 5 25 sodium hy...

Page 45: ...ir filter removes dirt or dust from the air and keeps the condenser from getting clogged As the filter gets clogged the icemaker s performance will be reduced Check the filter at least twice a month When clogged use warm water and a neutral cleaner to wash the filter 4 Condenser air cooled and remote air cooled models only Check the condenser once a year and clean if required by using a brush or v...

Page 46: ...r carbon dioxide until water stops coming out 2 Remove the water from the potable water supply line 1 Turn off the power supply and remove the front panel 2 Move the control switch on the control box to the OFF position 3 Wait 3 minutes 4 Close the potable water supply line shut off valve and open the potable water supply line drain valve 5 Allow the line to drain by gravity 6 Attach compressed ai...

Page 47: ... 631MRH C 0 and Later ON OFF OFF OFF ON ON OFF OFF OFF ON 2 S5 Dip Switch Settings S5 Dip Switch Do Not Adjust Model Auxiliary Code Dip Switch No 1 2 3 4 5 KML 250MAH B 1 and Later OFF OFF OFF OFF OFF KML 250MWH B 1 and Later OFF OFF OFF OFF OFF KML 351MAH V 1 and Later OFF OFF OFF OFF OFF KML 351MWH TBD OFF OFF OFF OFF OFF KML 451MAH B 1 and Later OFF OFF OFF OFF OFF KML 451MWH B 1 and Later OFF ...

Page 48: ...B Wiring Diagram 1 KML 451MAH and KML 451MWH B 1 and Later High Pressure Switch Air Cooled Model Water Cooled Model Cut out 412 22 PSIG 384 22 PSIG Cut in 327 22 PSIG 284 22 PSIG 0 0 A 2 ...

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