Mitsubishi Electric MUFZ-KJ25VEHZ Service Manual Download Page 1

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SERVICE MANUAL

Models

NOTE:

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

HFC

utilized

R410A

OUTDOOR UNIT

Indoor unit service manual
MFZ-KJ•VE Series (OBH666)

PARTS CATALOG (OBB668)

MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ

MUFZ-KJ25VEHZ

ER1

ER2

ET1

ET2

MUFZ-KJ35VEHZ

ER1

ER2

ET1

ET2

MUFZ-KJ50VEHZ

ER1

ER2

ET1

ET2

CONTENTS

1. TECHNICAL CHANGES ······························2
2. PART NAMES AND FUNCTIONS ··················3

3. SPECIFICATION ········································4

4. NOISE CRITERIA CURVES ··························6

5. OUTLINES AND DIMENSIONS ·····················7

6. WIRING DIAGRAM ·····································8

7. REFRIGERANT SYSTEM DIAGRAM ··········· 12

8. PERFORMANCE CURVES ························ 14

9. ACTUATOR CONTROL ····························· 25

10. SERVICE FUNCTIONS ······························ 26

11. TROUBLESHOOTING ······························· 27

12. DISASSEMBLY INSTRUCTIONS ················· 50

No. OBH668

REVISED EDITION-E

OBH668 REVISED EDITION-D is void.

Revision F:

• Resistance value of the defrost heater for

MUFZ-KJ25/35VEHZ -

ER1

ER2

ET1

ET2

has been corrected (11-4.).

Summary of Contents for MUFZ-KJ25VEHZ

Page 1: ...E1 E2 ER1 ER2 ET1 ET2 CONTENTS 1 TECHNICAL CHANGES 2 2 PART NAMES AND FUNCTIONS 3 3 SPECIFICATION 4 4 NOISE CRITERIA CURVES 6 5 OUTLINES AND DIMENSIONS 7 6 WIRING DIAGRAM 8 7 REFRIGERANT SYSTEM DIAGRAM 12 8 PERFORMANCE CURVES 14 9 ACTUATOR CONTROL 25 10 SERVICE FUNCTIONS 26 11 TROUBLESHOOTING 27 12 DISASSEMBLY INSTRUCTIONS 50 No OBH668 REVISED EDITION E OBH668 REVISED EDITION D is void Revision F ...

Page 2: ...n cycle When the repair or the inspection of the circuit needs to be done without turning off the power exercise great caution not to touch the live parts Use the specified refrigerant only Never use any refrigerant other than that specified Doing so may cause a burst an explosion or fire when the unit is being used serviced or disposed of Correct refrigerant is specified in the manuals and on the...

Page 3: ...g Air outlet Drain outlet Air inlet back and side Drain hose MUFZ KJ25VEHZ ER1 MUFZ KJ25VEHZ ER2 MUFZ KJ35VEHZ ER1 MUFZ KJ35VEHZ ER2 MUFZ KJ50VEHZ ER1 MUFZ KJ50VEHZ ER2 1 Model name has been changed MUFZ KJ25VEHZ ET1 MUFZ KJ25VEHZ ET2 MUFZ KJ35VEHZ ET1 MUFZ KJ35VEHZ ET2 MUFZ KJ50VEHZ ET1 MUFZ KJ50VEHZ ET2 1 Model name has been changed OBH668E ...

Page 4: ...l Model L 0 35 FV50S 0 4 FV50S Fan motor Model RC0J50 CI RC0J60 BC Current 1 Cooling A 0 28 0 82 Heating 0 31 0 82 Dimensions W H D mm 800 550 285 840 880 330 Weight kg 37 55 Special remarks Dehumidification Cooling L h 0 6 1 4 2 0 Air flow 1 Cooling Med m3 h 1 806 2 748 Low 1 038 1 632 Heating High 2 016 2 856 Med 1 710 2 748 Low 1 326 2 274 Sound level 1 Cooling dB A 46 47 49 Heating 51 Fan spee...

Page 5: ...Relay X63 3 A 250 V X64 20 A 250 V X66 3 A 250 V X69 10A 250V R V coil 21S4 220 240 V AC Heater protector 26H Open 45 C Specifications and rated conditions of main electric parts Model Item MUFZ KJ50VEHZ Smoothing capacitor CB1 CB2 CB3 560 μF 450 V Fuse F601 F880 F901 T3 15AL250 V Defrost heater H 230 V 120 W IGBT module IC932 5 A 600 V IC700 20 A 600 V Expansion valve coil LEV 12 V DC Reactor L 3...

Page 6: ...BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz COOLING FUNCTION SPL dB A LINE HEATING 47 51 NC 10 MUFZ KJ35VEHZ NOISE CRITERIA CURVES 4 Test conditions Cooling Dry bulb temperature 35 C Heating Dry bulb temperature 7 C Wet bulb temperature 6 C OUTDOOR UNIT MICROPHONE 1 m 90 80 70 60 50 40 30 20 10 63 125 250 500 1000 2000 4000 8000 NC 60 NC 50 NC 40 NC 30 NC 20 NC 70 O...

Page 7: ...1 100 mm or more when front and sides of the unit are clear 2 When any 2 sides of left right and rear of the unit are clear Clear 1 200 mm or more 2 OUTLINES AND DIMENSIONS 5 MUFZ KJ50VEHZ 417 5 40 42 Drain hole 175 500 330 50 Air in Air out 2 holes 10 21 360 840 109 81 880 452 Service panel 99 5 164 5 195 3 5 4 4 Liquid refrigerant pipe joint Refrigerant pipe flared Ø 6 35 Gas refrigerant pipe jo...

Page 8: ...8 WIRING DIAGRAM 6 MUFZ KJ25VEHZ E1 ER1 ET1 MUFZ KJ35VEHZ E1 ER1 ET1 OBH668E ...

Page 9: ...9 MUFZ KJ25VEHZ E2 ER2 ET2 MUFZ KJ35VEHZ E2 ER2 ET2 OBH668E ...

Page 10: ...10 MUFZ KJ50VEHZ E1 ER1 ET1 OBH668E ...

Page 11: ...11 MUFZ KJ50VEHZ E2 ER2 ET2 OBH668E ...

Page 12: ...0 Outdoor heat exchanger temperature thermistor RT68 Capillary tube ø3 0 ø2 0 210 with service port Muffler REFRIGERANT SYSTEM DIAGRAM 7 MUFZ KJ50VEHZ Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared connection Stop valve Stop valve Capillary tube ø4 0 ø2 4 100 Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heatin...

Page 13: ...15 12 7 6 35 ADDITIONAL REFRIGERANT CHARGE R410A g Model Outdoor unit precharged Refrigerant piping length one way 7 m 8 m 9 m 10 m 11 m 12 m 13 m 14 m 15 m 20 m MUFZ KJ25 35 1 100 0 30 60 90 120 150 180 210 240 390 Calculation X g 30 g m Refrigerant piping length m 7 Model Outdoor unit precharged Refrigerant piping length one way 7 m 10 m 15 m 20 m 25 m 30 m MUFZ KJ50 1 500 0 60 160 260 360 460 C...

Page 14: ...ometers to the indoor air intake as shown in the figure and at least 2 sets of wet and dry bulb thermometers to the indoor air outlet The thermometers must be attached to the position where air speed is high 2 Attach at least 2 sets of wet and dry bulb thermometers to the outdoor air intake Cover the thermometers to prevent direct rays of the sun 3 Check that the air filter is cleaned 4 Open windo...

Page 15: ...0 26 8 24 5 22 3 20 1 17 8 15 6 13 4 11 1 8 9 MUFZ KJ35VEHZ 28 0 25 9 23 7 21 6 19 4 17 2 15 1 12 9 10 8 8 6 MUFZ KJ50VEHZ Outdoor intake air Wet bulb temperature C 20 15 10 5 0 5 10 15 0 4 0 5 0 6 0 7 0 8 0 9 1 0 1 1 1 2 1 3 Heating capacity at Rated frequency Capacity correction factor 15 20 26 Indoor intake air Dry bulb temperature Indoor air Dry bulb temperature difference C 22 9 21 2 19 4 17 ...

Page 16: ...f compressor Hz Input correction factors The operational frequency of compressor Hz Correction of Cooling capacity Capacity correction factors Correction of Cooling input Input correction factors Correction of Heating capacity Capacity correction factors Correction of Heating input Capacity correction factors The operational frequency of compressor Hz The operational frequency of compressor Hz The...

Page 17: ...o MPa on the international system of units SI unit system The conversion factor is 1 MPa Gauge 10 2 kgf cm2 Gauge 15 20 25 30 35 1 5 2 0 2 5 3 0 15 20 25 30 35 2 5 3 0 3 5 4 0 4 5 Ambient temperature C Ambient humidity 50 60 70 50 60 70 Outdoor current A Ambient temperature C Ambient humidity Outdoor current A MUFZ KJ35VEHZ MUFZ KJ25VEHZ Outdoor unit current 50 60 70 15 20 25 30 35 3 4 5 6 7 8 MUF...

Page 18: ...7 535 27 24 3 35 1 84 0 55 491 3 23 1 77 0 55 518 3 15 1 73 0 55 535 3 05 1 68 0 55 562 27 26 3 45 1 48 0 43 518 3 35 1 44 0 43 545 3 30 1 42 0 43 562 3 20 1 38 0 43 578 28 18 2 94 2 79 0 95 432 2 81 2 67 0 95 454 2 70 2 57 0 95 475 2 60 2 47 0 95 497 28 20 3 06 2 54 0 83 454 2 94 2 44 0 83 481 2 85 2 37 0 83 491 2 75 2 28 0 83 513 28 22 3 19 2 26 0 71 470 3 08 2 18 0 71 500 3 00 2 13 0 71 513 2 8...

Page 19: ...7 605 2 38 1 59 0 67 626 27 24 2 88 1 58 0 55 594 2 70 1 49 0 55 621 2 55 1 40 0 55 648 27 26 3 03 1 30 0 43 616 2 85 1 23 0 43 643 2 68 1 15 0 43 670 28 18 2 45 2 33 0 95 529 2 25 2 14 0 95 562 2 08 1 97 0 95 583 28 20 2 58 2 14 0 83 551 2 40 1 99 0 83 578 2 23 1 85 0 83 610 28 22 2 73 1 93 0 71 572 2 55 1 81 0 71 605 2 38 1 69 0 71 626 28 24 2 88 1 70 0 59 594 2 70 1 59 0 59 621 2 55 1 50 0 59 6...

Page 20: ...931 27 24 4 69 2 02 0 43 855 4 52 1 94 0 43 902 4 41 1 90 0 43 931 4 27 1 84 0 43 978 27 26 4 83 1 50 0 31 902 4 69 1 45 0 31 949 4 62 1 43 0 31 978 4 48 1 39 0 31 1006 28 18 4 11 3 41 0 83 752 3 94 3 27 0 83 790 3 78 3 14 0 83 827 3 64 3 02 0 83 865 28 20 4 29 3 04 0 71 790 4 11 2 92 0 71 837 3 99 2 83 0 71 855 3 85 2 73 0 71 893 28 22 4 46 2 63 0 59 818 4 31 2 54 0 59 870 4 20 2 48 0 59 893 4 03...

Page 21: ...3 1 83 0 55 1090 27 24 4 03 1 73 0 43 1034 3 78 1 63 0 43 1081 3 57 1 54 0 43 1128 27 26 4 24 1 31 0 31 1072 3 99 1 24 0 31 1119 3 75 1 16 0 31 1166 28 18 3 43 2 85 0 83 921 3 15 2 61 0 83 978 2 91 2 41 0 83 1015 28 20 3 61 2 56 0 71 959 3 36 2 39 0 71 1006 3 12 2 21 0 71 1062 28 22 3 82 2 25 0 59 996 3 57 2 11 0 59 1053 3 33 1 96 0 59 1090 28 24 4 03 1 89 0 47 1034 3 78 1 78 0 47 1081 3 57 1 68 0...

Page 22: ... 27 24 6 70 2 75 0 41 1283 6 45 2 64 0 41 1354 6 30 2 58 0 41 1396 6 10 2 50 0 41 1466 27 26 6 90 2 00 0 29 1354 6 70 1 94 0 29 1424 6 60 1 91 0 29 1466 6 40 1 86 0 29 1509 28 18 5 88 4 76 0 81 1128 5 63 4 56 0 81 1184 5 40 4 37 0 81 1241 5 20 4 21 0 81 1297 28 20 6 13 4 23 0 69 1184 5 88 4 05 0 69 1255 5 70 3 93 0 69 1283 5 50 3 80 0 69 1340 28 22 6 38 3 63 0 57 1227 6 15 3 51 0 57 1304 6 00 3 42...

Page 23: ... 4 75 2 52 0 53 1636 27 24 5 75 2 36 0 41 1551 5 40 2 21 0 41 1621 5 10 2 09 0 41 1692 27 26 6 05 1 75 0 29 1607 5 70 1 65 0 29 1678 5 35 1 55 0 29 1748 28 18 4 90 3 97 0 81 1382 4 50 3 65 0 81 1466 4 15 3 36 0 81 1523 28 20 5 15 3 55 0 69 1438 4 80 3 31 0 69 1509 4 45 3 07 0 69 1593 28 22 5 45 3 11 0 57 1495 5 10 2 91 0 57 1579 4 75 2 71 0 57 1636 28 24 5 75 2 59 0 45 1551 5 40 2 43 0 45 1621 5 1...

Page 24: ...3 83 968 4 39 1045 4 95 1111 5 46 1144 6 02 1166 21 2 58 770 3 10 913 3 66 1012 4 17 1089 4 73 1144 5 25 1177 5 78 1221 26 2 32 825 2 88 968 3 40 1067 3 96 1144 4 52 1199 5 03 1232 5 59 1265 NOTE Q Total capacity kW INPUT Total power input W DB Dry bulb temperature WB Wet bulb temperature MUFZ KJ50VEHZ CAPACITY 6 0 kW INPUT 1610 W INDOOR DB C OUTDOOR WB C 10 5 0 5 10 15 20 Q INPUT Q INPUT Q INPUT ...

Page 25: ...OFF The fan motor turns OFF 15 seconds after the compressor has stopped running 9 3 RELATION BETWEEN MAIN SENSOR AND ACTUATOR 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 Defros...

Page 26: ...ation in which the thermostat is OFF for a long time at low outside temperature 0 C or less may cause the following troubles To prevent those troubles activate the pre heat control 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 turn...

Page 27: ... 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 MUFZ KJ25VEHZ MUFZ KJ35VEHZ MUFZ KJ50VEHZ TROUBLESHOOTING 11 3 Troubleshooting procedure 1 Check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off ...

Page 28: ...ons Press OPERATE STOP ON OFF MFZ KJ25 35 50VE STOP OPERATE OFF ON MFZ KJ25 35 50VE2 button of the remote controller the set temperature is displayed with the remote controller headed towards the indoor unit 1 Judgment of indoor outdoor abnormality 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 ...

Page 29: ...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 outdoor unit is normal Release the failure mode recall function accord ing to the left mentioned procedure Deleting the memorized abnormal condition After repairing the unit recall the failure mode again accordi...

Page 30: ...pressor current is distorted Reconnect the compressor connector Refer to 11 5 How to check inverter compressor 5 time flash 2 5 seconds OFF Discharge temperature Temperature of discharge temperature thermistor exceeds 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 100 C or less 3 minutes later Check the refrigerant circuit and the refrigerant amount Refer t...

Page 31: ...ve Closed valve 14 time flash 2 5 seconds OFF Closed valve is detected by compressor current Check the 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 Replace the inverter P C board Outdoor refrigerant system abnormality 17 time flash 2 5 seconds OFF A close...

Page 32: ...to 11 5 Check of LEV 11 4 time flash 2 5 seconds OFF Fin temperature P C board tem perature thermistor overheat protection Temperature of the fin temperature thermistor on the heat sink exceeds 75 86 C KJ25 35 75 80 C KJ50 or tem perature of P C board temperature thermistor on the inverter P C board exceeds 72 85 C KJ25 35 70 75 C KJ50 Check around the outdoor unit Check the outdoor unit air passa...

Page 33: ... the power supply voltage is high MUFZ KJ50 Zero cross detecting circuit Zero cross signal cannot be detected It occurs with following cases 1 Instantaneous power voltage drop Short time power failure 2 Distortion of primary voltage Refer to 11 5 Check of power supply 23 9 time flash 2 5 seconds OFF Inverter check mode The connector of compressor is disconnected inverter check mode starts Check if...

Page 34: ...ssor Measure the resistance between terminals using a tester Temperature 10 40 C Normal Ω MUFZ KJ25 35VEHZ MUFZ KJ50VEHZ 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 10 40 C Color of lead wire Normal Ω MUFZ KJ25 35VEHZ MUFZ KJ50VEHZ RED BLK BLK WHT WHT RED 12 16 12 17 R V coil 21S4 Measure the resistance using a tester Tempe...

Page 35: ...k of open phase C Check of compressor With the connector between the compressor and the power module IC700 MUFZ KJ25 35 IGBT module IC700 MUFZ KJ50 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 operation ...

Page 36: ...th 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 8 3 Measurement Measure the time from the start of compre...

Page 37: ...easure the resistance of thermistor MUFZ KJ25 35 Thermistor Symbol Connector Pin No Board Defrost RT61 Between CN641 pin1 and pin2 Inverter P C board Discharge temperature RT62 Between CN641 pin3 and pin4 Fin temperature RT64 Between CN642 pin1 and pin2 Ambient temperature RT65 Between CN643 pin1 and pin2 Outdoor heat exchanger temperature RT68 Between CN644 pin1 and pin3 MUFZ KJ50 Thermistor Symb...

Page 38: ...e 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 11 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 230...

Page 39: ...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 40: ...ht up or flash Refer to 11 6 1 No Replace the inverter P C board Is there bus bar voltage 260 370 VDC between DB61 and DB61 MUFZ KJ25 35 325 370 VDC between JP715 and JP30 MUFZ KJ50 on the inverter P C board Refer to 11 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 KJ25 35 IGBT module IC700 MUFZ KJ50 Turn ...

Page 41: ...og 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 11 4 Do you hear the expansion valve click click Do you feel the expansion valve vibrates on touching it Turn ON the power supply Preparation of ...

Page 42: ...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 11 3 Yes No Yes 10 time flash No L Check of inverter P C board OBH668E ...

Page 43: ...2 or more minutes after the power supply is turned on Touch S2 and S3 with tester probes and start the emergency operation No Turn the power supply ON When the emergency operation starts does the rated voltage occur for 2 seconds between indoor terminal block S2 and S3 Yes Replace the indoor electronic control P C board Does the left lamp of the OPERA TION INDICATOR lamp on the indoor unit blink c...

Page 44: ... No Does DC 10 V or more occur between L68A and L68B on the outdoor relay P C board Yes Does the outdoor LED blink 6 times Yes Replace the outdoor relay P C board 1 No Does DC more than 0 V occur between indoor terminal block S2 and S3 Yes Replace the outdoor inverter P C board 1 No Turn the power supply OFF Start the emergency operation No Repair has been completed Replace the outdoor inverter P ...

Page 45: ...e to read 0 C or below and let the defrost thermistor continue to read 1 C or below NOTE In case both thermistors are more than the above temperature cool them with cold water etc 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 operation has stopped to pre vent the d...

Page 46: ...c 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 air conditioner indoor outdoor w...

Page 47: ...EST POINT DIAGRAM AND VOLTAGE Fin temperature thermistor RT64 CN642 Ambient temperature thermistor RT65 CN643 Discharge temperature thermistor RT62 CN641 Defrost thermistor RT61 CN641 DB61 260 370 VDC Front side of unit 230 VAC Smoothing capacitor C62 Output to drive compressor LDU LDV LDW Fuse F701 T3 15AL250V Smoothing capacitor C61 Fuse F901 T3 15AL250V R V coil CN721 230 VAC Jumper wire for ch...

Page 48: ...tor RT64 Resistance k Resistance k Resistance k Fin temperature thermistor RT64 CN673 Ambient temperature thermistor RT65 CN672 Discharge temperature thermistor RT62 CN671 Defrost thermistor RT61 CN671 Output to drive outdoor fan motor CN932 Outdoor heat exchanger temperature thermistor RT68 CN671 Fuse F901 T3 15AL250V Fuse F880 T3 15AL250V LEV connector CN724 Jumper wire for changing defrost sett...

Page 49: ...49 2 Relay P C board MUFZ KJ50VEHZ To inverter P C board CN681 CN680 CN60 L68B L68A 10 VDC OBH668E ...

Page 50: ...s 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 Back panel Service panel Screws of the top panel Screws of the cabinet Screws of the top panel Screw of the service panel Direction to remove Screws of the cabinet Hooks Terminal with locking mechanism Detaching points The termin...

Page 51: ...the cabinet and panels Refer to 1 2 Disconnect the following connectors Inverter P C board CN721 R V coil 3 Remove the R V coil 4 Removing the discharge temperature thermistor defrost thermistor outdoor heat exchanger tempera ture thermistor and ambient temperature thermistor 1 Remove the cabinet and panels Refer to 1 2 Disconnect the lead wire to the reactor and the following con nectors Inverter...

Page 52: ...erter assembly Refer to 2 3 Recover gas from the refrigerant circuit NOTE Recover gas from the pipes until the pressure gauge shows 0 kg cm2 0 MPa 4 Detach the brazed part of the suction and the discharge pipe connected with compressor 5 Remove the nuts of compressor legs 6 Remove the compressor 7 Detach the brazed part of pipes connected with 4 way valve Ambient temperature thermistor Defrost the...

Page 53: ...op panel 6 Remove the valve cover 7 Disconnect the power supply and indoor outdoor connect ing wire 8 Remove the screws of the cabinet 9 Remove the cabinet 10 Remove the screws of the back panel 11 Remove the back panel Photo 2 Photo 1 Screws of the cabinet Screws of the top panel Screws of the cabinet Screws of the top panel Screw of the back panel Screws of the cabinet Screws of the service pane...

Page 54: ...he earth 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 relay panel 9 Disconnect the following connectors Relay P C board CN60 Terminal block CN680 Inverter P C board TAB65 Inverter P C board TB71 10 Remove the screws fixing the P B holder 11 Remove the relay P C board from the P B holder Photo 3 Photo 4 3 Removing...

Page 55: ...tor 1 Remove the top panel cabinet and service panel Refer 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 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 ass...

Page 56: ...8 REVISED EDITION D Issued Aug 2014 No OBH668 REVISED EDITION C Issued Jan 2014 No OBH668 REVISED EDITION B Issued Oct 2013 No OBH668 REVISED EDITION A Published Jun 2013 No OBH668 Made in Japan HEAD OFFICE TOKYO BLDG 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Specifications are subject to change without notice ...

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