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SERVICE MANUAL

Models

OUTDOOR UNIT

Indoor unit service manual
MFZ-KJ•NA Series (OBH752)

NOTE:

 

RoHS compliant products have <G> mark on the spec name plate.

HFC

utilized

R410A

PARTS CATALOG (OBB753)

MUFZ-KJ09NAHZ
MUFZ-KJ12NAHZ

MUFZ-KJ09NAHZ

    

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U1

MUFZ-KJ12NAHZ

    

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U1

MUFZ-KJ15NAHZ

    

-

 

U1

MUFZ-KJ18NAHZ

    

-

 

U1

CONTENTS

1. TECHNICAL CHANGES ······························2
2. PART NAMES AND FUNCTIONS ··················3
3. SPECIFICATION ········································4
4. OUTLINES AND DIMENSIONS ·····················6
5. WIRING DIAGRAM ·····································8
6. REFRIGERANT SYSTEM DIAGRAM ··········· 10
7. DATA······················································ 12
8. ACTUATOR CONTROL ····························· 20
9. SERVICE FUNCTIONS ······························ 21

10. TROUBLESHOOTING ······························· 22
11. DISASSEMBLY INSTRUCTIONS ················· 43

No. OBH753

REVISED EDITION-A

Revision A:

• 3. SPECIFICATION and 7-2. PERFORMANCE 

CURVE has been modified.

Please void OBH753.

Summary of Contents for MUFZ-KJ09NAHZ

Page 1: ...1 MUFZ KJ12NAHZ U1 MUFZ KJ15NAHZ U1 MUFZ KJ18NAHZ U1 CONTENTS 1 TECHNICAL CHANGES 2 2 PART NAMES AND FUNCTIONS 3 3 SPECIFICATION 4 4 OUTLINES AND DIMENSIONS 6 5 WIRING DIAGRAM 8 6 REFRIGERANT SYSTEM DIAGRAM 10 7 DATA 12 8 ACTUATOR CONTROL 20 9 SERVICE FUNCTIONS 21 10 TROUBLESHOOTING 22 11 DISASSEMBLY INSTRUCTIONS 43 No OBH753 REVISED EDITION A Revision A 3 SPECIFICATION and 7 2 PERFORMANCE CURVE h...

Page 2: ...sposed of Correct refrigerant is specified in the manuals and on the spec labels provided with our products We will not be held responsible for mechanical failure system malfunction unit breakdown or accidents caused by failure to follow the instructions MUFZ KJ09NAHZ MUFZ KJ12NAHZ MUFZ KJ15NAHZ MUFZ KJ18NAHZ 1 New model Revision A 3 SPECIFICATION and 7 2 PERFORMANCE CURVE has been modified OBH753...

Page 3: ...NAHZ MUFZ KJ12NAHZ MUFZ KJ15NAHZ MUFZ KJ18NAHZ Piping Air outlet Drain outlet Air inlet back and side Drain hose PART NAMES AND FUNCTIONS 2 Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH753A ...

Page 4: ...ime delay A 15 20 Min circuit ampacity A 11 16 Fan motor F L A 0 50 0 93 Compressor Model SNB140FQUMT SNB172FQKMT R L A 8 2 12 0 L R A 10 3 15 0 Refrigeration oil fl oz L Model 11 8 0 35 FV50S 13 5 0 40 FV50S Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 48 48 51 51 Heating dB A 50 50 55 55 Defrost method Reverse cycle Dimensions W in 31 1 2 33 1 16 D in 11 1 4 13 H in 21 5...

Page 5: ...sor Speed 70 60 17 15 H0 1 Heating Steady State at minimum compressor Speed 70 60 62 56 5 H1 1 Heating Steady State at minimum compressor Speed 70 60 47 43 H2 V Heating at Intermediate compressor Speed 5 70 60 35 33 5 At Intermediate compressor Speed Rated compressor speed minimum compressor speed 3 minimum compressor speed 3 4 2 OPERATION Mode Condition Intake air temperature F Indoor Outdoor DB ...

Page 6: ...e unit are clear 2 x hole 3 8 x 13 16 REQUIRED SPACE Liquid refrigerant pipe joint Refrigerant pipe flared Ø 1 4 Gas refrigerant pipe joint Refrigerant pipe flared Ø 3 8 4 in 100 mm or more 14 in 350 mm or more 8 in 200 mm or more 2 4 in 100 mm or more OUTLINES AND DIMENSIONS 4 Unit inch MUFZ KJ09NAHZ MUFZ KJ12NAHZ OBH753A ...

Page 7: ...nel 3 29 32 6 1 2 7 11 16 3 5 4 4 Liquid refrigerant pipe joint Refrigerant pipe flared Ø 1 4 Gas refrigerant pipe joint Refrigerant pipe flared Ø 1 2 1 20 in 500 mm or more when front and sides of the unit are clear 14in 350 mm or more 4 in 100 mm or more REQUIRED SPACE Clear 1 4 in 100 mm or more 20 in 500 mm or more 2 2 When any 2 sides of left right and rear of the unit are clear OBH753A ...

Page 8: ...8 5 WIRING DIAGRAM MUFZ KJ09NAHZ MUFZ KJ12NAHZ OBH753A ...

Page 9: ...9 MUFZ KJ15NAHZ MUFZ KJ18NAHZ OBH753A ...

Page 10: ...ary tube O D 0 118 I D 0 079 8 9 32 ø3 0 ø2 0 210 Service port Service port Stop valve with service port Muffler Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared connection Stop valve Capillary tube O D 0 157 I D 0 094 3 15 16 ø4 0 ø2 4 100 Refrigerant flow in cooling Compressor Service port 4 way valve Refrigerant flow in heating Refrig...

Page 11: ...ant charge according to the calculation Model Outdoor unit precharged Refrigerant piping length one way ft 25 30 40 50 60 65 MUFZ KJ09NAHZ MUFZ KJ12NAHZ 2 lb 10 oz 0 1 08 3 24 5 40 7 56 8 64 Calculation X oz 1 08 5 oz ft Refrigerant piping length ft 25 NOTE Refrigerant piping exceeding 25 ft requires additional refrigerant charge according to the calculation Model Outdoor unit precharged Refrigera...

Page 12: ... 4 7 8 0 94 MUFZ KJ15NAHZ 71 18 4 9 7 1 00 17 2 9 0 1 09 16 1 8 5 1 18 15 0 7 9 1 24 13 8 7 3 1 29 67 17 4 11 5 0 94 16 2 10 7 1 04 15 0 9 9 1 12 14 0 9 2 1 19 12 8 8 5 1 24 63 16 4 13 0 0 90 15 2 12 0 0 99 14 1 11 2 1 07 12 8 10 2 1 14 11 7 9 3 1 19 MUFZ KJ18NAHZ 71 20 8 10 8 1 20 19 5 10 1 1 32 18 3 9 4 1 42 17 0 8 8 1 49 15 6 8 1 1 55 67 19 7 12 8 1 13 18 4 11 9 1 25 17 0 11 1 1 35 15 8 10 3 1 ...

Page 13: ... 3 1 09 14 1 1 28 16 5 1 30 18 5 1 37 19 1 1 40 21 4 1 47 MUFZ KJ18NAHZ 75 9 2 1 14 12 2 1 41 15 2 1 63 18 2 1 69 20 5 1 77 21 1 1 80 23 9 1 87 70 10 0 1 10 12 9 1 37 15 8 1 60 18 6 1 64 21 0 1 73 21 6 1 76 24 5 1 83 65 10 5 1 05 13 2 1 31 16 5 1 55 19 2 1 60 21 6 1 69 22 3 1 71 25 0 1 80 NOTE 1 IDB Intake air dry bulb temperature TC Total Capacity x103 Btu h TPC Total Power Consumption kW 2 Above...

Page 14: ...ty correction factors 76 75 68 64 72 Indoor intake air Wet bulb temperature F Indoor air Wet bulb temperature difference F 71 67 63 65 75 85 95 105 115 0 8 0 9 1 0 1 1 1 2 1 3 1 4 Indoor intake air WB temperature F SHF at rating condition 0 66 431 CFM Airflow Outdoor intake air DB temperature F Total power consumption kW 71 67 63 65 75 85 95 105 115 0 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 Indoor intake ai...

Page 15: ... 1 0 0 1 0 0 1 8 8 7 7 Heating Capacity 13 Outdoor Temperature Degrees F 5 5 15 25 35 45 55 65 75 0 00 0 50 1 00 1 50 2 00 2 50 3 00 3 50 4 00 13 5 5 15 25 35 45 55 65 75 Heating Max Capacity Btu h Dry bulb temperature difference F 0 20 40 60 80 100 120 Heating Capacity HEATING CAPACITY Outdoor Temperature Degrees F 13 0 4 0 5 0 14 0 23 0 32 0 41 0 50 0 69 8 75 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 ...

Page 16: ... pressure Suction pressure Outdoor ambient temperature Indoor DB temperature F PSIG Indoor DB temperature F Outdoor ambient temperature 86 80 75 70 86 80 75 70 65 70 75 80 85 90 95 100 105 250 290 330 370 410 450 F F 65 70 75 80 85 90 95 100 105 120 130 140 150 160 170 180 PSIG Condensing pressure Suction pressure Outdoor ambient temperature Indoor DB temperature F PSIG Indoor DB temperature F Out...

Page 17: ...rature F MUFZ KJ12NAHZ 75 70 65 75 70 65 PSIG Condensing pressure Outdoor ambient temperature F F PSIG Suction pressure Outdoor ambient temperature 5 15 25 35 45 55 65 75 250 290 330 370 410 450 Indoor DB temperature F 5 15 25 35 45 55 65 75 50 70 90 110 130 150 170 190 210 Indoor DB tem perature F MUFZ KJ09NAHZ Heating Data are based on the condition of outdoor humidity 75 Air flow should be set ...

Page 18: ...2 Fan motor current A 0 41 0 37 0 40 0 36 0 41 0 37 0 40 0 36 1 21 1 09 1 24 1 12 1 21 1 09 1 24 1 12 Refrigerant circuit Condensing pressure PSIG 377 331 401 360 382 414 388 441 Suction pressure PSIG 172 126 159 121 158 127 154 124 Discharge temperature F 141 117 150 142 149 166 150 178 Condensing temperature F 109 98 113 104 110 112 111 117 Suction temperature F 60 37 52 36 55 38 51 41 Comp shel...

Page 19: ... 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 2 5 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 7 1 4 2 1 2 8 3 5 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 2 5 3 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 0 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 2 5 3 0 MUFZ KJ...

Page 20: ...TUATOR Sensor Purpose Actuator Compressor LEV Outdoor fan motor R V coil Indoor fan motor Defrost heater Discharge temperature thermistor Protection Indoor coil temperature thermistor Cooling Coil frost prevention Heating High pressure protec tion Defrost thermistor Heating Defrosting Fin temperature thermistor Protection Ambient temperature thermistor Cooling Low ambient tempera ture operation He...

Page 21: ...or a long time at low outside temperature 32 F 0 C or less may cause the following troubles The pre heat control prevents this interference 1 If moisture gets into the refrigerant cycle and freezes it may interfer the start up of the compressor 2 If liquid refrigerant collects in the compressor a failure in the compressor may occur The pre heat control turns ON when the compressor temperature is 6...

Page 22: ...g capacitor 4 When removing the electronic control P C board hold the edge of the board with care NOT to apply stress on the components 5 When connecting or disconnecting the connectors hold the connector housing DO NOT pull the lead wires 3 Troubleshooting procedure 1 Check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality To make sure check how ...

Page 23: ...mality Before blinking does the left lamp of the OPERATION INDI CATOR lamp stay ON for 3 seconds When it stays ON for 3 seconds without beep The outdoor unit is abnormal The indoor unit is abnormal Check the blinking pattern and identify the abnormal point by referring to the indoor unit failure mode table Refer to indoor unit service manual Make sure to check at least 2 consecutive blinking cycle...

Page 24: ...blinking pattern and identify the abnormal point by referring to the outdoor unit failure mode table 10 2 3 Make sure to check at least 2 consecutive blinking cycles 2 Releasing the failure mode recall function Release the failure mode recall function by the following procedures Turn OFF the power supply and turn it ON again Press RESET button of the remote controller Repair the failure parts The ...

Page 25: ...ty Compressor start up failure protection 12 time flash 2 5 seconds OFF Waveform of compressor current is distorted Reconnect compressor connector Refer to 10 5 How to check inverter compressor 5 time flash 2 5 seconds OFF Discharge temperature Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 212 F...

Page 26: ...Each phase current of compressor cannot be detected normally 14 time flash or more 2 5 seconds OFF Stop valve Closed valve 14 time flash 2 5 seconds OFF Closed valve is detected by compressor current Check stop valve 4 way valve Pipe temperature 16 time flash 2 5 seconds OFF The 4 way valve does not work properly The indoor coil thermistor detects an abnormal temperature Check the 4 way valve Repl...

Page 27: ...mpressor Check stop valve 9 3 time flash 2 5 seconds OFF Discharge tem perature overheat protection Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 212 F 100 C or less 3 minutes later Check refrigerant circuit and refrig erant amount Refer to 10 5 Check of LEV 10 4 time flash 2 5 seconds OFF Fin t...

Page 28: ...stors 20 Outdoor unit operates 7 time flash 2 5 seconds OFF Low discharge tem perature protection Temperature of discharge temperature thermistor has been 122 F 50 C or less for 20 minutes Refer to 10 5 Check of LEV Check refrigerant circuit and refrig erant amount 21 8 time flash 2 5 seconds OFF MUFZ KJ09 12 PAM protection PAM Pulse Ampli tude Modulation The overcurrent flows into PFC Power facto...

Page 29: ...f thermistor Compressor Measure the resistance between terminals using a tester Temperature 14 104 F 10 40 C Normal Ω MUFZ KJ09 12 MUFZ KJ15 18 U V U W V W 1 66 2 26 0 87 1 18 Outdoor fan motor Measure the resistance between lead wires using a tester Temperature 14 104 F 10 40 C Color of lead wire Normal Ω MUFZ KJ09 12 MUFZ KJ15 18 RED BLK BLK WHT WHT RED 29 40 12 16 R V coil 21S4 Measure the resi...

Page 30: ...eck of open phase C Check of compressor With the connector between the compressor and the power module IC700 MUFZ KJ09 12 IGBT module IC700 MUFZ KJ15 18 disconnected activate the inverter and check if the inverter is normal by measuring the voltage balance between the terminals Output voltage is 50 130 V The voltage may differ according to the tester Operation method Start cooling or heating opera...

Page 31: ...h a drier for about 20 minutes Do not recover refrigerant gas while heating Heating part Connect the compressor and activate the inverter Then measure the time until the inverter stops due to overcurrent Operation method Start heating or cooling operation by pressing EMERGENCY OPERATION switch on the indoor unit TEST RUN OPERATION Refer to 7 6 Measurement Measure the time from the start of compres...

Page 32: ... thermistor normal Refer to 10 6 1 Reconnect the connector of thermistor Turn ON the power supply and press EMERGENCY OPERATION switch Does the unit operate for 10 minutes or more without showing thermistor abnormality OK Cause is poor contact Yes Yes Disconnect the connector of thermistor in the inverter P C board see below table and measure the resistance of thermistor MUFZ KJ15 18 Thermistor Sy...

Page 33: ... power module IC700 Turn ON the power supply and press EMERGENCY OPERATION switch once COOL mode First of all measure the resistance of R V coil to check if the coil is defective Refer to 10 4 In case CN602 is disconnected or R V coil is open voltage is generated between the terminal pins of the connector although no signal is being transmitted to R V coil Check if CN602 is connected Is there 208 ...

Page 34: ...easure the voltage of CN931 Between 1 and 5 Between 2 and 5 Between 3 and 5 Does the voltage between each terminal become 5 and 0 VDC repeatedly Does the outdoor fan motor rotate smoothly Replace the outdoor fan motor Replace the inverter P C board Yes Yes No Fixed to either 5 or 0 VDC No No Yes Disconnect the connectors CN931 and CN932 from the inverter P C board Check the connection between the ...

Page 35: ...ht up or flash Refer to 10 6 1 No Replace the inverter P C board Is there DC voltage 260 370 VDC between DB61 and DB61 MUFZ KJ09 12 294 370 VDC between JP715 and JP30 MUFZ KJ15 18 on the inverter P C board Refer to 10 6 1 No Check the electric parts in main circuit Yes Yes No Disconnect the connector between the compressor and the power module IC700 MUFZ KJ09 12 IGBT module IC700 MUFZ KJ15 18 Turn...

Page 36: ...he voltage by an analog tester Properly fix the LEV coil to the expansion valve Replace the inverter P C board Replace the LEV coil Replace the expansion valve Is LEV coil properly fixed to the expansion valve Does the resistance of LEV coil have the characteristics Refer to 10 4 Do you hear the expansion valve click click Do you feel the expansion valve vibrate when touching it Turn ON the power ...

Page 37: ...oor fan motor If the connection is poor make it correct Operate the outdoor unit by starting EMERGENCY OPERATION Check the LED indication on the in verter P C board Does the LED flash 10 times Replace the inverter P C board Check the corresponding parts following LED indication Refer to 10 3 Yes No Yes 10 time flash No L Check of inverter P C board OBH753A ...

Page 38: ... 6 second OFF and 0 8 second ON quick blinking 3 Yes No Lighted or not lighted Replace the inverter P C board 2 2 Be careful of the residual voltage of smoothing capacitor Is there amplitude of 10 to 20 VDC between the indoor terminal block S2 and S3 Confirmation of serial signal Yes Check the wiring If there are any error of the indoor outdoor connecting wire such as the damage of the wire interm...

Page 39: ...d let the defrost thermistor continue to read 30 F 1 C or below NOTE In case both thermistors are more than the above temperature cool them with cold water etc MUFZ KJ09NAHZ MUFZ KJ12NAHZ MUFZ KJ15NAHZ MUFZ KJ18NAHZ Has the operation stopped during pump down Was the operation started with the stop valve closed and was it opened during operation No Yes O Check of outdoor refrigerant circuit The ope...

Page 40: ...ondition combination of specific conditions such as antennas or wiring Check the following before asking for service 1 Devices affected by the electromagnetic noise TV sets radios FM AM broadcast shortwave 2 Channel frequency broadcast station affected by the electromagnetic noise 3 Channel frequency broadcast station unaffected by the electromagnetic noise 4 Layout of indoor outdoor unit of the a...

Page 41: ...CN931 208 230 VAC Outdoor heat exchanger temperature thermistor RT68 CN644 Jumper wire for pre heat control setting JK Refer to 9 2 Heater connector CN722 Fuse F801 T3 15AL250V Back side of unit LEV connector CN724 Output to drive outdoor fan motor CN932 LED 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat ...

Page 42: ...ing JK Refer to 9 2 Fuse F601 T3 15AL250V Signal of out door fan motor CN931 R V coil CN602 208 230 VAC 294 370 VDC JP715 JP30 LED Heater connector CN601 208 230 VAC 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat exchanger temperature thermistor RT68 32 50 68 86 104 122 140 158 176 0 20 40 60 80 100 120 1...

Page 43: ... sleeve and check if there is a locking lever or not 2 The terminal with this connector has the locking mechanism Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pull out the terminal slowly Connector Sleeve Locking lever Terminal with locking mechanism Detaching points The terminal which has the locking mechanism can be detached as shown below There are 2 ty...

Page 44: ...al block support and the back panel 6 Remove the inverter assembly 7 Remove the screw of the ground wire and screw of the ter minal block support 8 Remove the heat sink support from the P C board support 9 Remove the screw of the inverter P C board and remove the inverter P C board from the P C board support Photo 6 3 Removing R V coil 1 Remove the cabinet and panels Refer to 1 2 Disconnect the fo...

Page 45: ...re ther mistor CN643 Ambient temperature thermistor CN644 Outdoor heat exchanger temperature thermistor 3 Pull out the discharge temperature thermistor from its holder 4 Pull out the defrost thermistor from its holder Photo 6 5 Pull out the outdoor heat exchanger temperature thermistor from its holder Photo 6 6 Pull out the ambient temperature thermistor from its holder Photo 8 Photo 9 Photo 10 45...

Page 46: ...nverter assembly Refer to 2 3 Remove the screws fixing the reactor 4 Remove the reactor 5 Remove the soundproof felt 6 Recover gas from the refrigerant circuit NOTE Recover gas from the pipes until the pressure gauge shows 0 PSIG 7 Detach the brazed part of the suction and the discharge pipe connected with compressor 8 Remove the nuts fixing the compressor 9 Remove the compressor 10 Detach the bra...

Page 47: ...Remove the conduit plate 9 Remove the top panel 10 Remove the valve cover 11 Disconnect the power supply and indoor outdoor connect ing wire 12 Remove the screws of the cabinet 13 Remove the cabinet 14 Remove the screws of the back panel 15 Remove the back panel Photo 2 Photo 1 Photo 3 Photo 4 47 Screws of the cabinet Screws of the top panel Screws of the cabinet Screws of the top panel Screw of t...

Page 48: ...ector 3 Remove the compressor connector 4 Remove the screws fixing the relay panel 5 Remove the relay panel 6 Remove the ground wires and the lead wires of the inverter P C board 7 Remove the screws of the P B support 8 Remove the inverter P C board from the P B support Photo 5 Photo 6 3 Removing R V coil 1 Remove the cabinet and panels Refer to 1 2 Disconnect the following connector Inverter P C ...

Page 49: ...fer to 1 2 Disconnect the following connectors Inverter P C board CN931 and CN932 Fan motor 3 Remove the propeller fan 4 Remove the screws fixing the fan motor 5 Remove the fan motor NOTE The propeller fan nut is a revers thread 6 Removing the compressor and 4 way valve 1 Remove the top panel cabinet and service panel Refer to 1 2 Remove the back panel Refer to 1 3 Remove the inverter assembly Ref...

Page 50: ...ributed in Mar 2016 No OBH753 REVISED EDITION A Distributed in Feb 2016 No OBH753 Made in Japan HEAD OFFICE TOKYO BLDG 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN New publication effective Mar 2016 Specifications are subject to change without notice ...

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