Mitsubishi Electric MUZ-BT20VG Service Manual Download Page 10

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WIRING DIAGRAM

MUZ-BT20VG -

ER1

MUZ-BT25VG -

ER1

MUZ-BT35VG -

ER1

MUZ-BT20VG -

ET1

MUZ-BT25VG -

ET1

MUZ-BT35VG -

ET1

SİGORTA

İNVERTER

BASKILI

DEVRE KARTI

İÇ ÜNİTE

230V 50Hz

GÜÇ

KAYNAĞI

NOTLAR :
1. İç ünite elektronik kablolaması için iç ünite
elektronik kablo devre şemasını referans alınız.
2. Sadece bakır besleme kablosu kullanın.
3. Sembolleri gösterir.

LED Göstergeleri ile Arıza Giderme

:Terminal bloğu

:Konnektör

CN61

C62

DB61,DB65

F61,F62

F701

801

901

IC700,IC932

IC802

LED

KONNEKTÖR

KAPASİTÖR

DİYOT MODÜLÜ

SİGORTA (15A 250V)

SİGORTA (T

15AL250V)

GÜÇ MODÜLÜ

GÜÇ CİHAZI

LED

LEV

L61

PTC65

Q821

RT61

RT62

GENLEŞME VANASI SARGISI

REAKTÖR

KOMPRESÖR

FAN MOTORU

DEVRE KORUMASI

SİVİÇLİ GÜÇ TRANSİSTÖRÜ

DEFROST TERMİSTÖRÜ

BASMA SI

AKLIK TERMİSTÖRÜ

RT64

RT65

TB1

T801

X63,X64,X69

21S4

FİN SICAKLIK TERMİSTÖRÜ

ORTAM SI

AKLIK TERMİSTÖRÜ

TERMİNAL BLOĞU

TRANSFORMATÖR

RÖLE

4 YOLLU VANA SARGISI

RT68

DIŞ ÜNİTE EŞANJÖR

SICAKLIK TERMİSTÖRÜ

SEMBOL

PARÇA ADI

SEMBOL

PARÇA ADI

SEMBOL

PARÇA ADI

OBH850A

Summary of Contents for MUZ-BT20VG

Page 1: ...NS 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 BT20VG MUZ BT25VG MUZ BT35VG Models MUZ BT20VG E1 ER1 ET1 MUZ BT25VG E1 ER1 ET1 MUZ BT35VG E1 ER1 ET1 MUZ BT50VG E1 ER1 ET1 Indoor unit service manual MSZ BT VG Series OBH849 No OBH850 REVISED EDITION A OBH850 is vo...

Page 2: ...s 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 fire when the unit is being us...

Page 3: ...g 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 refrigeran...

Page 4: ...ly 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 its...

Page 5: ...G PART NAMES AND FUNCTIONS 3 ACCESSORIES MODELS MUZ BT20VG MUZ BT25VG MUZ BT35VG MUZ BT50VG Drain socket 1 MUZ BT50VG Air outlet Drain outlet Piping Drain hose Air inlet Back and side MUZ BT25VG MUZ BT35VG Drain outlet Air outlet Air inlet back and side Piping Drain hose OBH850A ...

Page 6: ... FW68S 0 35 FW68S Fan motor Model RC0J20 AB RC0J50 NC Current 1 Cooling A 0 24 0 23 0 20 Heating 0 24 0 23 0 26 0 23 Dimensions W H D mm 699 538 249 800 550 285 Weight kg 23 24 35 Special remarks Dehumidification Cooling L h 0 1 0 3 0 8 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 1 260 1 350 1 260 Sound level 1 Cooli...

Page 7: ...dule DB61 15 A 600 V 15 A 600 V Diode module DB65 25 A 600 V Fuse F61 15A 250V 25A 250V F62 15A 250V F701 F801 F901 T3 15AL250V Power module IC700 15 A 600 V 20 A 600 V IC932 5 A 600 V Expansion valve coil LEV 12 V DC Reactor L61 18 mH 23 mH Switch power 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...

Page 8: ...90 63 125 250 500 1000 2000 4000 8000 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz NC 70 NC 60 NC 50 NC 40 NC 30 NC 20 COOLING FUNCTION SPL dB A LINE 50 HEATING 50 10 20 30 40 50 60 70 80 90 63 125 250 500 1000 2000 4000 8000 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz COOLING FUNCTION SPL dB A LINE 52 HEATING 52 NC 70 NC...

Page 9: ...9 Unit mm MUZ BT20VG MUZ BT25VG MUZ BT35VG OUTLINES AND DIMENSIONS 6 MUZ BT20VG MUZ BT25VG MUZ BT35VG MUZ BT25 35VG only MUZ BT50VG OBH850A ...

Page 10: ...nal bloğu Konnektör CN61 C62 DB61 DB65 F61 F62 F701 F801 F901 IC700 IC932 IC802 LED KONNEKTÖR KAPASİTÖR DİYOT MODÜLÜ SİGORTA 15A 250V SİGORTA T3 15AL250V GÜÇ MODÜLÜ GÜÇ CİHAZI LED LEV L61 MC MF PTC65 Q821 RT61 RT62 GENLEŞME VANASI SARGISI REAKTÖR KOMPRESÖR FAN MOTORU DEVRE KORUMASI SİVİÇLİ GÜÇ TRANSİSTÖRÜ DEFROST TERMİSTÖRÜ BASMA SICAKLIK TERMİSTÖRÜ RT64 RT65 TB1 T801 X63 X64 X69 21S4 FİN SICAKLIK...

Page 11: ...11 MUZ BT50VG E1 ER1 MUZ BT50VG ET1 OBH850A ...

Page 12: ...top valve with service port Capillary tube ø4 0 ø2 4 100 Muffler REFRIGERANT SYSTEM DIAGRAM 8 MUZ BT20VG MUZ BT25VG MUZ BT35VG MUZ BT50VG 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 Refriger...

Page 13: ...12 9 52 6 35 MUZ BT50VG 12 7 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 BT20VG 450 0 20 40 60 80 100 120 140 160 260 MUZ BT25VG 500 MUZ BT35VG 500 MUZ BT50VG 700 Calculation X g 20 g m Refrigerant piping length m 7 NOTE Refrigerant piping exceeding 7 m requires additional refrigerant charge ...

Page 14: ... 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 o...

Page 15: ... 5 3 MUZ BT50VG MUZ BT35VG MUZ BT25VG Indoor air Dry bulb temperature difference C 13 7 12 7 11 6 10 6 9 5 8 5 7 4 6 3 5 3 4 2 MUZ BT20VG Outdoor intake air Wet bulb temperature C 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 17 3 16 0 14 6 13 3 12 0 10 7 9 3 8 0 6 7 5 3 19 8 ...

Page 16: ...eating input Capacity correction 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 C...

Page 17: ...ST 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 fre...

Page 18: ...humidity Outdoor current A Outdoor current A 0 5 10 15 20 25 0 5 1 0 1 5 2 0 2 5 0 5 10 15 20 25 2 3 4 5 6 0 5 10 15 20 25 1 0 1 5 2 0 2 5 3 0 0 5 10 15 20 25 1 0 1 5 2 0 2 5 3 0 MUZ BT20VG MUZ BT25VG Outdoor unit current MUZ BT35VG MUZ BT50VG Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A Ambient temperature C Outdoor curren...

Page 19: ... 446 27 24 2 68 1 85 0 69 410 2 58 1 78 0 69 432 2 52 1 74 0 69 446 2 44 1 68 0 69 468 27 26 2 76 1 57 0 57 432 2 68 1 53 0 57 455 2 64 1 50 0 57 468 2 56 1 46 0 57 482 28 18 2 35 2 35 1 00 360 2 25 2 25 1 00 378 2 16 2 16 1 00 396 2 08 2 08 1 00 414 28 20 2 45 2 38 0 97 378 2 35 2 28 0 97 401 2 28 2 21 0 97 410 2 20 2 13 0 97 428 28 22 2 55 2 17 0 85 392 2 46 2 09 0 85 416 2 40 2 04 0 85 428 2 30...

Page 20: ... 504 1 90 1 54 0 81 522 27 24 2 30 1 59 0 69 495 2 16 1 49 0 69 518 2 04 1 41 0 69 540 27 26 2 42 1 38 0 57 513 2 28 1 30 0 57 536 2 14 1 22 0 57 558 28 18 1 96 1 96 1 00 441 1 80 1 80 1 00 468 1 66 1 66 1 00 486 28 20 2 06 2 00 0 97 459 1 92 1 86 0 97 482 1 78 1 73 0 97 509 28 22 2 18 1 85 0 85 477 2 04 1 73 0 85 504 1 90 1 62 0 85 522 28 24 2 30 1 68 0 73 495 2 16 1 58 0 73 518 2 04 1 49 0 73 54...

Page 21: ... 693 27 24 3 35 2 08 0 62 637 3 23 2 00 0 62 672 3 15 1 95 0 62 693 3 05 1 89 0 62 728 27 26 3 45 1 73 0 50 672 3 35 1 68 0 50 707 3 30 1 65 0 50 728 3 20 1 60 0 50 749 28 18 2 94 2 94 1 00 560 2 81 2 81 1 00 588 2 70 2 70 1 00 616 2 60 2 60 1 00 644 28 20 3 06 2 76 0 90 588 2 94 2 64 0 90 623 2 85 2 57 0 90 637 2 75 2 48 0 90 665 28 22 3 19 2 49 0 78 609 3 08 2 40 0 78 648 3 00 2 34 0 78 665 2 88...

Page 22: ...784 2 38 1 76 0 74 812 27 24 2 88 1 78 0 62 770 2 70 1 67 0 62 805 2 55 1 58 0 62 840 27 26 3 03 1 51 0 50 798 2 85 1 43 0 50 833 2 68 1 34 0 50 868 28 18 2 45 2 45 1 00 686 2 25 2 25 1 00 728 2 08 2 08 1 00 756 28 20 2 58 2 32 0 90 714 2 40 2 16 0 90 749 2 23 2 00 0 90 791 28 22 2 73 2 13 0 78 742 2 55 1 99 0 78 784 2 38 1 85 0 78 812 28 24 2 88 1 90 0 66 770 2 70 1 78 0 66 805 2 55 1 68 0 66 840...

Page 23: ... 24 4 69 2 53 0 54 1128 4 52 2 44 0 54 1190 4 41 2 38 0 54 1228 4 27 2 31 0 54 1290 27 26 4 83 2 03 0 42 1190 4 69 1 97 0 42 1252 4 62 1 94 0 42 1290 4 48 1 88 0 42 1327 28 18 4 11 3 87 0 94 992 3 94 3 70 0 94 1042 3 78 3 55 0 94 1091 3 64 3 42 0 94 1141 28 20 4 29 3 52 0 82 1042 4 11 3 37 0 82 1104 3 99 3 27 0 82 1128 3 85 3 16 0 82 1178 28 22 4 46 3 12 0 70 1079 4 31 3 01 0 70 1147 4 20 2 94 0 7...

Page 24: ...3 33 2 19 0 66 1438 27 24 4 03 2 17 0 54 1364 3 78 2 04 0 54 1426 3 57 1 93 0 54 1488 27 26 4 24 1 78 0 42 1414 3 99 1 68 0 42 1476 3 75 1 57 0 42 1538 28 18 3 43 3 22 0 94 1215 3 15 2 96 0 94 1290 2 91 2 73 0 94 1339 28 20 3 61 2 96 0 82 1265 3 36 2 76 0 82 1327 3 12 2 55 0 82 1401 28 22 3 82 2 67 0 70 1314 3 57 2 50 0 70 1389 3 33 2 33 0 70 1438 28 24 4 03 2 33 0 58 1364 3 78 2 19 0 58 1426 3 57...

Page 25: ...7 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 0...

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: ... 70 780 2 11 915 2 49 1009 2 90 1082 3 31 1134 3 69 1165 4 10 1196 MUZ BT35VG CAPACITY 3 60 kW INPUT 930 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 27 605 2 74 725 3 20 818 3 67 884 4 14 939 4 57 967 5 04 986 21 2 16 651 2 59 772 3 06 856 3 49 921 3 96 967 4 39 995 4 84 1032 26 1 94 698 2 41 818 2 84 902 3 31 967 3 78 1014 4 21 1042 4 ...

Page 28: ...r 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 Protection...

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 contro...

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: ...T button First release RESET button Hold down the other 2 buttons for another 3 seconds Make sure that the indicators on the LCD screen shown in the right figure are all displayed Then release the buttons Press OFF ON stop operate 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 Befor...

Page 32: ...de 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 recall the failure...

Page 33: ...rent 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 tempe...

Page 34: ...rter 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 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 work properly The indoor coil...

Page 35: ...and 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...

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: ...t 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 BT20 25 35VG MUZ BT50VG 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 BT20 25 35VG MUZ BT50VG 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 seconds...

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: ... the inverter P C board Replace the 4 way valve Unit operates in 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 in HEAT mode even if it is set to COOL mode Disconnect connector between the compressor and the IGBT module IC...

Page 42: ...asure 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 the...

Page 43: ...n 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 EMERGEN...

Page 44: ...age 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: ...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 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 OBH850A ...

Page 46: ... OFF and wiring is not loose No Does DC 6 V or more occur between indoor terminal block S2 and S3 Yes Replace the outdoor inverter P C board 1 No Replace the indoor electronic control P C board 1 Electric charge may remain immediately after the power supply is turned OFF Perform the procedure after 3 minutes Replace the outdoor inverter P C board 1 Yes No Was the indoor unit ever connected to the ...

Page 47: ...ir 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 no...

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: ...fan motor CN932 R V coil 21S4 CN721 Outdoor heat exchanger RT68 CN644 Ambient tem peraturer RT65 CN643 Fuse F62 15A 250V 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 thermistor RT62 0 10 20 30 40 50 60 70 80 0 20 40 60 80 100 120 1...

Page 50: ...r RT64 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 RT...

Page 51: ...l 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 mech...

Page 52: ...l block support 8 Remove the screw of the earth wire 9 Remove the screw of the terminal block and remove the terminal block 10 Remove the heat sink support from the P C board support 11 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 conn...

Page 53: ...r from its holder Photo 8 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 ...

Page 54: ...f the separator and remove the separator 5 Remove the soundproof felt 6 Remove 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...

Page 55: ...crews 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 3 Photo 1 Photo 2 Back panel Service panel Screws of the top panel Screws of the terminal block support and the back panel Screws of the cabinet Screws of the back panel Screws of the top panel Direction to remove Scre...

Page 56: ...et and 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 I...

Page 57: ...ection 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 ...

Page 58: ... 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Copyright 2019 MITSUBISHI ELECTRIC CORPORATION Issued Dec 2019 No OBH850 REVISED EDITION A Published Oct 2019 No OBH850 Made in Japan Specifications are subject to change without notice ...

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