Mitsubishi Electric MUZ-HR25 Page 38 Service Manual Download

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12-5. TROUBLESHOOTING FLOW

A How to check inverter/compressor

Refer to 12-5. “Check of compressor

operation time”.

Does the compressor operate continuously?

Refer to 12-5. “Check of compressor start failure”.

Yes

Refer to 12-5. “Check of compressor

winding”.

Is the compressor normal?

Replace the compressor.

Yes

B Check of open phase

C Check of compressor

● With the connector between the compressor and the power module (IC700) 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 by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERA-

TION: Refer to 9-3.)

<<Measurement point>>

At 3 points

BLK (U)-WHT (V)

BLK (U)-RED (W)

WHT(V)-RED (W)

NOTE

: 1. Output voltage varies according to power supply voltage.

2. Measure the voltage by analog type tester.

3. During this check, LED of the inverter P.C. board blinks 9 times. (Refer to 12-6.1.)

Measure AC voltage between the lead wires at 3 points.

Are the voltages balanced?

Disconnect the connector between the compressor

and the power module (IC700).

Replace the inverter P.C. board.

Check the voltage between terminals.

Check the compressor.

See 12-5. “Check of compressor”.

Yes

See 12-5. “Check of open phase”.

OBH823

Summary of Contents for MUZ-HR25

Page 1: ...ATION 6 5 NOISE CRITERIA CURVES 7 6 OUTLINES AND DIMENSIONS 9 7 WIRING DIAGRAM 10 8 REFRIGERANT SYSTEM DIAGRAM 12 9 PERFORMANCE CURVES 14 10 ACTUATOR CONTROL 28 11 SERVICE FUNCTIONS 29 12 TROUBLESHOOTING 30 13 DISASSEMBLY INSTRUCTIONS 51 MUZ HR42VF MUZ HR50VF Models MUZ HR25VF E1 ER1 ET1 MUZ HR35VF E1 ER1 ET1 MUZ HR42VF E1 ER1 ET1 MUZ HR50VF E1 ER1 ET1 Indoor unit service manual MSZ HR VF Series O...

Page 2: ...ater into the electric parts Do not touch the refrigerant Do not touch the hot or cold areas in the refrigeration 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 fir...

Page 3: ...ng changed they shall be fit for the purpose and to the correct specification At all times the manufacturer s maintenance and service guidelines shall be followed If in doubt consult the manufacturer s technical department for assistance The following checks shall be applied to installations using flammable refrigerants The charge size is in accordance with the room size within which the refrigera...

Page 4: ...ely familiar with the equipment and all its detail It is recommended good practice that all refrigerants are recovered safely Prior to the task being carried out an oil and refrigerant sample shall be taken in case analysis is required prior to re use of reclaimed refrigerant It is essential that electrical power is available before the task is commenced a Become familiar with the equipment and it...

Page 5: ...Air inlet Back and side MUZ HR25VF MUZ HR35VF PART NAMES AND FUNCTIONS 3 ACCESSORIES MODELS MUZ HR25VF MUZ HR35VF MUZ HR42VF MUZ HR50VF Drain socket 1 MUZ HR42VF MUZ HR50VF Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH823 ...

Page 6: ...oil Model L 0 27 FW68S 0 35 FW68S Fan motor Model RC0J55 DC Current 1 Cooling A 0 24 0 23 0 20 Heating 0 24 0 23 Dimensions W H D mm 699 538 249 800 550 285 Weight kg 23 24 34 35 Special remarks Dehumidification Cooling L h 0 8 1 1 1 6 2 0 Air flow 1 Cooling High m3 h 1 818 1 932 2 058 Low 990 1 050 906 Heating High 1 932 2 052 1 962 Med 1 680 1 788 1 686 Low 1 356 1 452 1 260 Sound level 1 Coolin...

Page 7: ...transistor Q821 30 37 A 600 V Current limiting PTC thermistor PTC64 33 Ω PTC65 33 Ω Terminal block TB1 5 P Relay X63 3 A 250 V X64 20 A 250 V R V coil 21S4 220 240 V AC 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 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz COOLING FUNCTION SPL dB A LINE HEATING 50 50 NC 10...

Page 8: ... 10 51 MUZ HR42VF 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 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz COOLING FUNCTION SPL dB A LINE HEATING 50 NC 10 51 MUZ HR50VF Test conditions Cooling Dry bulb temperature 35 C Wet bulb temperature 24 C Heating Dry bulb temperature 7 C Wet bulb temperature 6 C OUTDO...

Page 9: ...9 Unit mm MUZ HR25VF MUZ HR35VF OUTLINES AND DIMENSIONS 6 MUZ HR35VF MUZ HR42VF MUZ HR50VF OBH823 ...

Page 10: ...10 WIRING DIAGRAM 7 MUZ HR25VF E1 ER1 MUZ HR35VF E1 ER1 MUZ HR25VF ET1 MUZ HR35VF ET1 OBH823 ...

Page 11: ...11 MUZ HR42VF E1 ER1 MUZ HR50VF E1 ER1 MUZ HR42VF ET1 MUZ HR50VF ET1 OBH823 ...

Page 12: ...ermistor RT68 Stop valve with service port Muffler REFRIGERANT SYSTEM DIAGRAM 8 MUZ HR25VF MUZ HR35VF MUZ HR42VF MUZ HR50VF Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared connection Stop valve With strainer Stop valve with service port Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Refrigerant pipe ø9 52...

Page 13: ...2 50VF 20 12 9 52 6 35 ADDITIONAL REFRIGERANT CHARGE R32 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 MUZ HR25VF 400 0 20 40 60 80 100 120 140 160 260 MUZ HR35VF 450 MUZ HR42VF 700 MUZ HR50VF 800 Calculation X g 20 g m Refrigerant piping length m 7 NOTE Refrigerant piping exceeding 7 m requires additional refrigerant charge accord...

Page 14: ...e 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 windows and doors ...

Page 15: ...7 5 22 4 20 7 19 0 17 2 15 5 13 8 12 1 10 3 8 6 6 9 MUZ HR25VF MUZ HR50VF MUZ HR42VF MUZ HR35VF 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 20 4 18 8 17 3 15 7 14 1 12 6 11 0 9 4 7 8 6 ...

Page 16: ...tion factors The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz The operational frequency of compressor Hz Correction of Cooling capacity The operatio...

Page 17: ... RUN OPERATION Refer to 9 3 9 4 OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT Dry bulb temperature C Relative humidity 20 50 25 60 30 70 9 3 HOW TO OPERATE FIXED FREQUENCY OPERATION Test run operation 1 Press EMERGENCY OPERATION switch to start COOL or HEAT mode COOL Press once HEAT Press twice 2 Test run operation starts and continues to operate for 30 minutes 3 Compressor operates at rated frequ...

Page 18: ...R25VF Outdoor unit current MUZ HR42VF MUZ HR50VF 0 5 10 15 20 25 1 5 2 0 2 5 3 0 0 5 10 15 20 25 4 5 5 0 5 5 6 0 0 5 10 15 20 25 2 0 2 5 3 0 3 5 4 0 0 5 10 15 20 25 2 0 2 5 3 0 3 5 4 0 Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A MUZ HR35VF MUZ HR25VF Outdoor unit current MUZ HR42VF M...

Page 19: ... 792 27 24 3 35 1 61 0 48 728 3 23 1 55 0 48 768 3 15 1 51 0 48 792 3 05 1 46 0 48 832 27 26 3 45 1 24 0 36 768 3 35 1 21 0 36 808 3 30 1 19 0 36 832 3 20 1 15 0 36 856 28 18 2 94 2 59 0 88 640 2 81 2 48 0 88 672 2 70 2 38 0 88 704 2 60 2 29 0 88 736 28 20 3 06 2 33 0 76 672 2 94 2 23 0 76 712 2 85 2 17 0 76 728 2 75 2 09 0 76 760 28 22 3 19 2 04 0 64 696 3 08 1 97 0 64 740 3 00 1 92 0 64 760 2 88...

Page 20: ... 896 2 38 1 43 0 60 928 27 24 2 88 1 38 0 48 880 2 70 1 30 0 48 920 2 55 1 22 0 48 960 27 26 3 03 1 09 0 36 912 2 85 1 03 0 36 952 2 68 0 96 0 36 992 28 18 2 45 2 16 0 88 784 2 25 1 98 0 88 832 2 08 1 83 0 88 864 28 20 2 58 1 96 0 76 816 2 40 1 82 0 76 856 2 23 1 69 0 76 904 28 22 2 73 1 74 0 64 848 2 55 1 63 0 64 896 2 38 1 52 0 64 928 28 24 2 88 1 50 0 52 880 2 70 1 40 0 52 920 2 55 1 33 0 52 96...

Page 21: ...7 24 4 56 2 19 0 48 1101 4 39 2 11 0 48 1162 4 28 2 06 0 48 1198 4 15 1 99 0 48 1258 27 26 4 69 1 69 0 36 1162 4 56 1 64 0 36 1222 4 49 1 62 0 36 1258 4 35 1 57 0 36 1295 28 18 4 00 3 52 0 88 968 3 83 3 37 0 88 1016 3 67 3 23 0 88 1065 3 54 3 11 0 88 1113 28 20 4 17 3 17 0 76 1016 4 00 3 04 0 76 1077 3 88 2 95 0 76 1101 3 74 2 84 0 76 1150 28 22 4 34 2 77 0 64 1053 4 18 2 68 0 64 1119 4 08 2 61 0 ...

Page 22: ...3 23 1 94 0 60 1404 27 24 3 91 1 88 0 48 1331 3 67 1 76 0 48 1392 3 47 1 66 0 48 1452 27 26 4 11 1 48 0 36 1379 3 88 1 40 0 36 1440 3 64 1 31 0 36 1500 28 18 3 33 2 93 0 88 1186 3 06 2 69 0 88 1258 2 82 2 48 0 88 1307 28 20 3 50 2 66 0 76 1234 3 26 2 48 0 76 1295 3 03 2 30 0 76 1367 28 22 3 71 2 37 0 64 1283 3 47 2 22 0 64 1355 3 23 2 07 0 64 1404 28 24 3 91 2 03 0 52 1331 3 67 1 91 0 52 1392 3 47...

Page 23: ...27 24 5 63 2 48 0 44 1219 5 42 2 38 0 44 1286 5 29 2 33 0 44 1327 5 12 2 25 0 44 1394 27 26 5 80 1 85 0 32 1286 5 63 1 80 0 32 1353 5 54 1 77 0 32 1394 5 38 1 72 0 32 1434 28 18 4 94 4 15 0 84 1072 4 73 3 97 0 84 1126 4 54 3 81 0 84 1179 4 37 3 67 0 84 1233 28 20 5 15 3 70 0 72 1126 4 94 3 55 0 72 1193 4 79 3 45 0 72 1219 4 62 3 33 0 72 1273 28 22 5 36 3 21 0 60 1166 5 17 3 10 0 60 1240 5 04 3 02 ...

Page 24: ...3 99 2 23 0 56 1554 27 24 4 83 2 13 0 44 1474 4 54 2 00 0 44 1541 4 28 1 88 0 44 1608 27 26 5 08 1 63 0 32 1528 4 79 1 53 0 32 1595 4 49 1 44 0 32 1662 28 18 4 12 3 46 0 84 1313 3 78 3 18 0 84 1394 3 49 2 93 0 84 1447 28 20 4 33 3 11 0 72 1367 4 03 2 90 0 72 1434 3 74 2 69 0 72 1514 28 22 4 58 2 75 0 60 1420 4 28 2 57 0 60 1501 3 99 2 39 0 60 1554 28 24 4 83 2 32 0 48 1474 4 54 2 18 0 48 1541 4 28...

Page 25: ...27 24 6 70 2 88 0 43 1866 6 45 2 77 0 43 1968 6 30 2 71 0 43 2030 6 10 2 62 0 43 2132 27 26 6 90 2 14 0 31 1968 6 70 2 08 0 31 2071 6 60 2 05 0 31 2132 6 40 1 98 0 31 2194 28 18 5 88 4 88 0 83 1640 5 63 4 67 0 83 1722 5 40 4 48 0 83 1804 5 20 4 32 0 83 1886 28 20 6 13 4 35 0 71 1722 5 88 4 17 0 71 1825 5 70 4 05 0 71 1866 5 50 3 91 0 71 1948 28 22 6 38 3 76 0 59 1784 6 15 3 63 0 59 1896 6 00 3 54 ...

Page 26: ...4 75 2 61 0 55 2378 27 24 5 75 2 47 0 43 2255 5 40 2 32 0 43 2358 5 10 2 19 0 43 2460 27 26 6 05 1 88 0 31 2337 5 70 1 77 0 31 2440 5 35 1 66 0 31 2542 28 18 4 90 4 07 0 83 2009 4 50 3 74 0 83 2132 4 15 3 44 0 83 2214 28 20 5 15 3 66 0 71 2091 4 80 3 41 0 71 2194 4 45 3 16 0 71 2317 28 22 5 45 3 22 0 59 2173 5 10 3 01 0 59 2296 4 75 2 80 0 59 2378 28 24 5 75 2 70 0 47 2255 5 40 2 54 0 47 2358 5 10...

Page 27: ...2 41 858 2 84 946 3 31 1014 3 78 1063 4 21 1092 4 68 1121 MUZ HR42VF CAPACITY 4 70 kW INPUT 1300 W INDOOR DB C OUTDOOR WB C 10 5 0 5 10 15 20 Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT 15 2 96 845 3 57 1014 4 18 1144 4 79 1235 5 41 1313 5 97 1352 6 58 1378 21 2 82 910 3 38 1079 4 00 1196 4 56 1287 5 17 1352 5 73 1391 6 32 1443 26 2 54 975 3 15 1144 3 71 1261 4 32 1352 4 94 1417 5 50 1...

Page 28: ...er the compressor has stopped running 10 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 Defrosting Fin temperature thermistor Protectio...

Page 29: ... of the compressor at low outside temperature The pre heat control prevents this interference The pre heat control turns ON when the discharge temperature thermis tor is 20 C or below When the pre heat control turns ON the compressor is energized About 50 W Pre heat control setting JK ON To activate the pre heat control cut the JK wire of the inverter P C board OFF To deactivate the pre heat contr...

Page 30: ...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 TROUBLESHOOTING 12 3 Troubleshooting procedure 1 Check if the OPERATION INDICATOR lamp on the indoor unit is blinking on and off to indicate an abnormality To make sure che...

Page 31: ... Does the left lamp on the indoor unit 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 table of indoor unit failure mode recall function Refer to indoor unit service manual Make sure to check at least 2 consecutive blinking cycles 2 Releasing the...

Page 32: ...he 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 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 recal...

Page 33: ...ge current flows into power module IC700 Reconnect compressor connector Refer to 12 5 How to check inverter compressor Check stop valve Compressor synchronous abnormality Compressor start up failure protection 12 time blink 2 5 seconds OFF Waveform of compressor current is distorted Reconnect compressor connector Refer to 12 5 How to check inverter compressor 5 time blink 2 5 seconds OFF Discharge...

Page 34: ... How to check inverter compressor Each phase current of compressor 9 time blink 2 5 seconds OFF Each phase current of compressor cannot be detected normally 14 time blink or more 2 5 seconds OFF Stop valve Closed valve 14 time blink 2 5 seconds OFF Closed valve is detected by compressor current Check stop valve 4 way valve Pipe temperature 16 time blink 2 5 seconds OFF The 4 way valve does not wor...

Page 35: ... refrig erant amount Refer to 12 5 Check of LEV 11 4 time blink 2 5 seconds OFF Fin temperature P C board tem perature thermistor overheat protection Temperature of fin temperature thermistor on the heat sink exceeds 75 86 C or temperature of P C board temperature thermistor on the inverter P C board exceeds 72 85 C Check around outdoor unit Check outdoor unit air passage Refer to 12 5 Check of ou...

Page 36: ...ction PAM pro tection will be activated in the fol lowing cases 1 Instantaneous power voltage drop Short time power failure 2 When the power supply voltage is high 23 9 time blink 2 5 seconds OFF Inverter check mode The connector of compressor is disconnected inverter check mode starts Check if the connector of the com pressor is correctly connected Refer to 12 5 How to check inverter compressor N...

Page 37: ...nt diagram and voltage 1 Inverter P C board for the chart of thermistor Compressor Measure the resistance between terminals using a tester Temperature 10 40 C Normal Ω MUZ HR25 35VF MUZ HR42 50VF U V U W V W 1 59 2 16 0 82 1 11 W U V WHT RED BLK Outdoor fan motor Measure the resistance between lead wires using a tester Temperature 10 40 C Color of lead wire Normal Ω MUZ HR25 35VF MUZ HR42 50VF RED...

Page 38: ...50 130 V The voltage may differ according to the tester Operation method Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit TEST RUN OPERA TION Refer to 9 3 Measurement point At 3 points BLK U WHT V BLK U RED W WHT V RED W NOTE 1 Output voltage varies according to power supply voltage 2 Measure the voltage by analog type tester 3 During this check LED of t...

Page 39: ... TEST RUN OPERATION Refer to 9 3 Measurement Measure the time from the start of compressor to the stop of compressor due to overcurrent Compressor starts Abnormal IC700 failure Compressor winding short Abnormal Compressor lock out Starting defect Abnormal Poor contact Inverter P C board defect Disconnected connector Abnormal Refrigerant circuit defect Closed valve Normal 0 second 1 second 2 second...

Page 40: ... 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 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 CN64...

Page 41: ...lace the inverter P C board Replace the 4 way valve Unit operates COOL mode even if it is set to HEAT mode Is there 230 V AC between CN721 and on the inverter P C board 3 minutes after the power supply is turned ON Yes No Replace the inverter P C board Replace the 4 way valve Unit operates HEAT mode even if it is set to COOL mode Disconnect connector between the compressor and the IGBT module IC70...

Page 42: ...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 V DC 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 V DC No No Yes Disconnect the connectors CN931 and CN932 from the inverter P C board Check the connection between th...

Page 43: ...amp on the indoor unit light up Does LED on the inverter P C board light up or blink Refer to 12 6 1 No Replace the inverter P C board Is there bus bar voltage 260 370 V DC between DB61 and DB61 on the inverter P C board Refer to 12 6 1 No Check the electric parts in main circuit Yes Yes No Disconnect the connector between the compressor and the power module IC700 Turn ON power supply and press EM...

Page 44: ...tage 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 12 4 Do you hear the expansion valve click click Do you feel the expansion valve vibrate when touching it Turn ON the power supply...

Page 45: ...door 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 blink 10 times Replace the inverter P C board Check the corresponding parts following LED indication Refer to 12 3 Yes No Yes 10 time blink No L Check of inverter P C board OBH823 ...

Page 46: ...t them No A Turn OFF the power supply Check once more if the indoor outdoor connecting wire is not miswiring Bridge the outdoor terminal block S2 and S3 1 B 1 Miswiring may damage indoor electronic control P C board during the operation Be sure to confirm the wiring is correct before the opera tion starts Turn ON the power supply Does the LED on the inverter P C board repeat 3 6 second OFF and 0 8...

Page 47: ...air trapped in the refrigerant circuit Close the stop valve and disconnect the power plug or turn the breaker OFF The unit occasionally stops when the stop valve is opened or closed during operation Open the stop valve and start the cooling operation again Yes No The refrigerant gas amount may be 60 or less than the normal amount Identify where the gas is leaking from and fix the leak CAUTION Do n...

Page 48: ...he installation condition 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 outd...

Page 49: ...rive outdoor fan motor CN932 R V coil 21S4 CN721 Smoothing capacitor C62 Fuse F701 T3 15AL250V Outdoor heat exchanger RT68 CN644 Ambient tem peraturer RT65 CN643 Fuse F901 T3 15AL250V 20 10 0 10 20 30 40 0 10 20 30 40 50 60 70 80 90 100 Temperature C Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat exchanger temperature thermistor RT68 Temperature C Discharge temperature th...

Page 50: ...4 CN642 Ambient temperature thermistor RT65 CN643 Discharge temperature thermistor RT62 CN641 Defrost thermistor RT61 CN641 DB61 260 370 V DC Front side of unit 230 V AC Output to drive compressor LDU LDV LDW Fuse F701 T3 15AL250V R V coil 21S4 CN721 230 V AC Jumper wire for changing defrost setting JS Signal of outdoor fan motor CN931 230 V AC Outdoor heat exchanger temperature thermistor RT68 CN...

Page 51: ...inal with this connector shown below 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 Detaching method of the terminal with locking mechanism The terminal which has the locking mechanism can be detached as shown below There are following 2 types of the terminal with locking m...

Page 52: ... screws of the earth wire and the terminal block support 7 Remove the screw of the terminal block and remove the terminal block 8 Remove the heat sink support from the P C board support 9 Unhook the catch of the inverter P C board and remove the inverter P C board from the P C board support 3 Removing the R V coil 1 Remove the cabinet and the panels Refer to section 1 2 Disconnect the following co...

Page 53: ...to 9 5 Pull out the outdoor heat exchanger temperature ther mistor from its holder 6 Pull out the ambient temperature thermistor from its holder 5 Removing the outdoor fan motor 1 Remove the cabinet and the panels Refer to section 1 2 Disconnect the following connectors Inverter P C board CN931 CN932 Fan motor 3 Remove the fan motor lead wire from where it is fas tened on the separator 4 Remove th...

Page 54: ...move the terminal cover and the compressor lead wire 7 Recover gas from the refrigerant circuit NOTE Recover gas from the pipes until the pressure gauge shows 0 kg cm2 0 MPa 8 Detach the brazed part of the suction and the dis charge pipe connected with the compressor 9 Detach the brazed part of pipes connected with the 4 way valve 10 Remove the nuts of compressor legs 11 Remove the compressor 54 P...

Page 55: ...ng wire 4 Remove the screws fixing the top panel 5 Remove the top panel 6 Remove the screws fixing the cabinet 7 Remove the cabinet 8 Remove the screws fixing the back panel 9 Remove the back panel Photo 1 Photo 2 55 Back panel Service panel Screws of the cabinet Screws of the top panel Screw of the cabinet Screws of the back panel Screws of the terminal block support and the back panel Screws of ...

Page 56: ... panels Refer to section 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 section 1 2 Disconnect the lead wire to the reactor and the following con nectors Inverte...

Page 57: ...tion 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 7 Removing the LEV assembly 1 Detaching the brazed part of pi...

Page 58: ...ICE TOKYO BUILDING 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Copyright 2018 MITSUBISHI ELECTRIC CORPORATION Published Oct 2018 No OBH823 Made in Japan Specifications are subject to change without notice ...

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