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Mitsubishi Electric MUZ-AP25VG Service Manual Download Page 68

OPERATING PROCEDURE

PHOTOS/FIGURES

3. Removing R. V. coil 

(1) Remove the cabinet 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.

Photo 6

Photo 7

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:
<Inverter P.C. board>

CN641 (Defrost thermistor and discharge temperature 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.
(5) Pull out the outdoor heat exchanger temperature thermistor 

from its holder.

(6) Pull out the ambient temperature thermistor from its holder. 

5. Removing outdoor fan motor

(1) Remove the cabinet and panels. (Refer to section 1.)
(2) Disconnect the following connectors:
 

<Inverter P.C. board>

CN931, CN932 (Fan motor)

(3) Remove the propeller fan nut.
(4) Remove the propeller fan.
(5) Remove the screws fixing the fan motor.
(6) Remove the fan motor.

Photo 8

68

Discharge temperature thermistor

Screw of the R.V. coil

Defrost thermistor

Outdoor heat 
exchanger tempera-
ture thermistor

Ambient temperature 
thermistor

Screws of the outdoor fan motor

Propeller fan

Propeller fan nut

OBH789A

Summary of Contents for MUZ-AP25VG

Page 1: ... 8 REFRIGERANT SYSTEM DIAGRAM 18 9 PERFORMANCE CURVES 21 10 ACTUATOR CONTROL 40 11 SERVICE FUNCTIONS 41 12 TROUBLESHOOTING 42 13 DISASSEMBLY INSTRUCTIONS 63 Models MUZ AP25VG E1 ET1 E2 ET2 ER2 MUZ AP25VGH E1 E2 MUZ AP35VG E1 ET1 E2 ET2 ER2 MUZ AP35VGH E1 E2 MUZ AP42VG E1 ET1 E2 ET2 ER2 MUZ AP42VGH E1 E2 MUZ AP50VG E1 ET1 MUZ AP50VGH E1 MUZ AP60VG E1 ET1 MUZ AP71VG E1 ET1 MUZ AP25VG MUZ AP35VG MUZ ...

Page 2: ...ectric parts Precautions during the repair service Do not perform the work involving the electric parts with wet hands Do not pour water 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 U...

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: ...H MUZ AP42VGH PART NAMES AND FUNCTIONS 3 ACCESSORIES MODELS MUZ AP25VG MUZ AP35VG MUZ AP42VG MUZ AP50VG MUZ AP60VG MUZ AP71VG Drain socket 1 MUZ AP50VG MUZ AP60VG MUZ AP50VGH Air outlet Drain outlet Piping Drain hose Air inlet back and side MUZ AP71VG Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH789A ...

Page 6: ... Fan motor Model E1 ET1 RC0J50 NC E2 ET2 ER2 RC0J55 DC RC0J50 RA Current 1 Cooling A 0 22 0 22 0 20 0 27 Heating 0 20 0 24 0 23 0 27 Dimensions W H D mm 800 550 285 800 714 285 Weight kg 31 31 35 40 Special remarks Dehumidification Cooling L h 0 3 0 6 1 4 1 9 Air flow 1 Cooling High m3 h 2 178 2 178 2 058 2 430 Low 1 038 1 038 906 1 320 Heating High 2 076 2 076 1 962 2 430 Med 1 788 1 788 1 686 2 ...

Page 7: ...l RC0J50 RA RC0J77 AG Current 1 Cooling A 0 50 0 93 Heating 0 50 0 88 Dimensions W H D mm 800 714 285 840 880 330 Weight kg 40 55 Special remarks Dehumidification Cooling L h 1 5 2 4 Air flow 1 Cooling High m3 h 3 126 3 246 Med 2 748 2 958 Low 1 320 1 566 Heating High 3 126 2 958 Med 2 238 2 874 Low 1 704 2 334 Sound level 1 Cooling dB A 56 Heating 57 55 Fan speed Cooling High rpm 1 060 950 Med 94...

Page 8: ...r 26H Open 45 C Open 45 C Open 45 C Open 45 C Model Item MUZ AP60VG Smoothing capacitor C61 C62 C63 600 µF 620 µF 420 V Diode module DB61 25 A 600 V DB65 25 A 600 V Fuse F61 25A 250V F62 15A 250V F701 F801 F901 T3 15AL250V Power module IC700 20 A 600 V IC932 5 A 600 V Expansion valve coil LEV 12 V DC Reactor L61 23 mH Switch power transistor Q821 30 A 600 V Circuit protection PTC64 PTC65 33 Ω Term...

Page 9: ...CTION SPL dB A LINE HEATING 49 50 NC 10 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 AP25VG MUZ AP25VGH MUZ AP35VG MUZ AP35VGH NOISE CRITERIA CURVES 5 MUZ AP42VG MUZ AP42VGH 90 80 70 60 50 40 30 20 10 63 125 2...

Page 10: ... 56 55 Test conditions Cooling Dry bulb temperature 35 C Wet bulb temperature 24 C Heating Dry bulb temperature 7 C Wet bulb temperature 6 C OUTDOOR UNIT MICROPHONE 1 m MUZ AP60VG 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 BAND CENTER FREQUENCIES Hz NC 10 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR COOLING FUNCTION SPL dB A LINE HE...

Page 11: ...11 Unit mm MUZ AP25VG MUZ AP35VG MUZ AP42VG MUZ AP25VGH MUZ AP35VGH MUZ AP42VGH MUZ AP25 35 42VG MUZ AP25 35 42VGH OUTLINES AND DIMENSIONS 6 OBH789A ...

Page 12: ...12 Unit mm MUZ AP50VG MUZ AP60VG MUZ AP50VGH MUZ AP50VG H MUZ AP60VG OBH789A ...

Page 13: ...ant pipe joint Refrigerant pipe flared Ø 6 35 Gas refrigerant pipe joint Refrigerant pipe flared Ø 12 7 Air in 350 mm or more 100 mm or more REQUIRED SPACE 100 mm or more 500 mm or more 2 1 500 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 MUZ AP71VG Unit mm OBH789A ...

Page 14: ...14 WIRING DIAGRAM 7 MUZ AP25VG E1 ET1 E2 ET2 ER2 MUZ AP35VG E1 ET1 E2 ET2 ER2 MUZ AP25VGH E1 E2 MUZ AP35VGH E1 E2 OBH789A ...

Page 15: ...15 MUZ AP42VG E1 ET1 E2 ET2 ER2 MUZ AP42VGH E1 E2 OBH789A ...

Page 16: ...16 MUZ AP50VG E1 ET1 MUZ AP50VGH E1 OBH789A ...

Page 17: ...17 MUZ AP60VG E1 ET1 MUZ AP71VG E1 ET1 OBH789A ...

Page 18: ...p valve with service port Muffler REFRIGERANT SYSTEM DIAGRAM 8 Unit mm MUZ AP42VG MUZ AP42VGH Outdoor heat exchanger Flared connection Discharge temperature thermistor RT62 Flared connection Stop valve with strainar Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Refrigerant pipe ø9 52 with heat insulator Refrigerant pipe ø6 35 with heat insulator R V coil heating ON...

Page 19: ... way valve Refrigerant flow in heating Refrigerant pipe ø6 35 with heat insulator Refrigerant pipe ø9 52 MUZ AP50VG H ø12 7 MUZ AP60VG with heat insulator R V coil heating ON cooling OFF Strainer 100 LEV Ambient temperature thermistor RT65 Muffler Capillary tube ø4 0 ø2 4 240 Outdoor heat exchanger temperature thermistor RT68 Capillary tube ø3 0 ø2 0 210 x2 Muffler MUZ AP50VG MUZ AP60VG MUZ AP50VG...

Page 20: ...d Refrigerant piping length one way 15 m 16 m 17 m 20 m 25 m 30 m MUZ AP60VG 1 050 0 20 40 100 200 300 MUZ AP71VG 1 500 Calculation X g 20 g m Refrigerant piping length m 15 NOTE Refrigerant piping exceeding 7 m requires additional refrigerant charge according to the calculation Unit mm Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared co...

Page 21: ...he 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 of room 5 Press the EMERGENCY OPERATION switch once twice to start the EMERGENCY COOL HEAT MODE 6 Wh...

Page 22: ... 20 2 18 5 16 8 15 2 13 5 11 8 10 1 8 4 6 7 MUZ AP60VG 27 6 25 5 23 3 21 2 19 1 17 0 14 9 12 7 10 6 8 5 MUZ AP71VG MUZ AP42VGH MUZ AP35VGH 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 16...

Page 23: ...ating 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 Co...

Page 24: ... 1 5 0 50 100 150 0 5 1 0 1 5 2 0 0 50 100 150 0 5 1 0 1 5 0 50 100 150 0 5 1 0 1 5 2 0 MUZ AP60VG Correction of Cooling capacity The operational frequency of compressor Hz Capacity correction factors Correction of Cooling input The operational frequency of compressor Hz Input correction factors Correction of Heating capacity The operational frequency of compressor Hz Capacity correction factors C...

Page 25: ...nt temperature C Ambient humidity Outdoor low pressure MUZ AP25VG MUZ AP35VG MUZ AP42VG MUZ AP50VG MUZ AP25VGH MUZ AP35VGH MUZ AP42VGH MUZ AP50VGH kgf cm2 Gauge MPa Gauge 7 5 3 9 11 13 MUZ AP60VG kgf cm2 Gauge MPa Gauge 4 2 0 6 8 10 MUZ AP71VG 50 60 70 Ambient temperature C Ambient humidity 50 60 70 Ambient temperature C Ambient humidity COOL operation Both indoor and outdoor unit are under the sa...

Page 26: ...ent humidity Outdoor current A 50 60 70 50 60 70 50 60 70 50 60 70 50 60 70 50 60 70 0 5 10 15 20 25 2 0 2 5 3 0 3 5 4 0 0 5 10 15 20 25 5 5 6 0 6 5 7 0 0 5 10 15 20 25 2 0 2 5 3 0 3 5 4 0 0 5 10 15 20 25 4 5 5 0 5 5 6 0 6 5 0 5 10 15 20 25 5 0 5 5 6 0 6 5 7 0 0 5 10 15 20 25 5 5 6 0 6 5 7 0 7 5 Ambient temperature C Outdoor current A Ambient temperature C Outdoor current A Ambient temperature C O...

Page 27: ...3 0 74 594 27 24 3 35 2 08 0 62 546 3 23 2 00 0 62 576 3 15 1 95 0 62 594 3 05 1 89 0 62 624 27 26 3 45 1 73 0 50 576 3 35 1 68 0 50 606 3 30 1 65 0 50 624 3 20 1 60 0 50 642 28 18 2 94 2 94 1 00 480 2 81 2 81 1 00 504 2 70 2 70 1 00 528 2 60 2 60 1 00 552 28 20 3 06 2 76 0 90 504 2 94 2 64 0 90 534 2 85 2 57 0 90 546 2 75 2 48 0 90 570 28 22 3 19 2 49 0 78 522 3 08 2 40 0 78 555 3 00 2 34 0 78 57...

Page 28: ... 0 74 672 2 38 1 76 0 74 696 27 24 2 88 1 78 0 62 660 2 70 1 67 0 62 690 2 55 1 58 0 62 720 27 26 3 03 1 51 0 50 684 2 85 1 43 0 50 714 2 68 1 34 0 50 744 28 18 2 45 2 45 1 00 588 2 25 2 25 1 00 624 2 08 2 08 1 00 648 28 20 2 58 2 32 0 90 612 2 40 2 16 0 90 642 2 23 2 00 0 90 678 28 22 2 73 2 13 0 78 636 2 55 1 99 0 78 672 2 38 1 85 0 78 696 28 24 2 88 1 90 0 66 660 2 70 1 78 0 66 690 2 55 1 68 0 ...

Page 29: ...0 27 24 4 69 2 72 0 58 901 4 52 2 62 0 58 950 4 41 2 56 0 58 980 4 27 2 48 0 58 1030 27 26 4 83 2 22 0 46 950 4 69 2 16 0 46 1000 4 62 2 13 0 46 1030 4 48 2 06 0 46 1059 28 18 4 11 4 03 0 98 792 3 94 3 86 0 98 832 3 78 3 70 0 98 871 3 64 3 57 0 98 911 28 20 4 29 3 69 0 86 832 4 11 3 54 0 86 881 3 99 3 43 0 86 901 3 85 3 31 0 86 941 28 22 4 46 3 30 0 74 861 4 31 3 19 0 74 916 4 20 3 11 0 74 941 4 0...

Page 30: ...109 3 33 2 33 0 70 1148 27 24 4 03 2 33 0 58 1089 3 78 2 19 0 58 1139 3 57 2 07 0 58 1188 27 26 4 24 1 95 0 46 1129 3 99 1 84 0 46 1178 3 75 1 72 0 46 1228 28 18 3 43 3 36 0 98 970 3 15 3 09 0 98 1030 2 91 2 85 0 98 1069 28 20 3 61 3 10 0 86 1010 3 36 2 89 0 86 1059 3 12 2 68 0 86 1119 28 22 3 82 2 82 0 74 1049 3 57 2 64 0 74 1109 3 33 2 46 0 74 1148 28 24 4 03 2 50 0 62 1089 3 78 2 34 0 62 1139 3...

Page 31: ...1287 27 24 5 63 2 65 0 47 1183 5 42 2 55 0 47 1248 5 29 2 49 0 47 1287 5 12 2 41 0 47 1352 27 26 5 80 2 03 0 35 1248 5 63 1 97 0 35 1313 5 54 1 94 0 35 1352 5 38 1 88 0 35 1391 28 18 4 94 4 29 0 87 1040 4 73 4 11 0 87 1092 4 54 3 95 0 87 1144 4 37 3 80 0 87 1196 28 20 5 15 3 86 0 75 1092 4 94 3 70 0 75 1157 4 79 3 59 0 75 1183 4 62 3 47 0 75 1235 28 22 5 36 3 37 0 63 1131 5 17 3 25 0 63 1203 5 04 ...

Page 32: ... 1456 3 99 2 35 0 59 1508 27 24 4 83 2 27 0 47 1430 4 54 2 13 0 47 1495 4 28 2 01 0 47 1560 27 26 5 08 1 78 0 35 1482 4 79 1 68 0 35 1547 4 49 1 57 0 35 1612 28 18 4 12 3 58 0 87 1274 3 78 3 29 0 87 1352 3 49 3 03 0 87 1404 28 20 4 33 3 24 0 75 1326 4 03 3 02 0 75 1391 3 74 2 80 0 75 1469 28 22 4 58 2 88 0 63 1378 4 28 2 70 0 63 1456 3 99 2 51 0 63 1508 28 24 4 83 2 46 0 51 1430 4 54 2 31 0 51 149...

Page 33: ...1535 27 24 6 70 2 95 0 44 1411 6 45 2 84 0 44 1488 6 30 2 77 0 44 1535 6 10 2 68 0 44 1612 27 26 6 90 2 21 0 32 1488 6 70 2 14 0 32 1566 6 60 2 11 0 32 1612 6 40 2 05 0 32 1659 28 18 5 88 4 94 0 84 1240 5 63 4 73 0 84 1302 5 40 4 54 0 84 1364 5 20 4 37 0 84 1426 28 20 6 13 4 41 0 72 1302 5 88 4 23 0 72 1380 5 70 4 10 0 72 1411 5 50 3 96 0 72 1473 28 22 6 38 3 83 0 60 1349 6 15 3 69 0 60 1434 6 00 ...

Page 34: ... 1736 4 75 2 66 0 56 1798 27 24 5 75 2 53 0 44 1705 5 40 2 38 0 44 1783 5 10 2 24 0 44 1860 27 26 6 05 1 94 0 32 1767 5 70 1 82 0 32 1845 5 35 1 71 0 32 1922 28 18 4 90 4 12 0 84 1519 4 50 3 78 0 84 1612 4 15 3 49 0 84 1674 28 20 5 15 3 71 0 72 1581 4 80 3 46 0 72 1659 4 45 3 20 0 72 1752 28 22 5 45 3 27 0 60 1643 5 10 3 06 0 60 1736 4 75 2 85 0 60 1798 28 24 5 75 2 76 0 48 1705 5 40 2 59 0 48 178...

Page 35: ...7 24 8 17 4 33 0 53 1447 7 87 4 17 0 53 1526 7 69 4 07 0 53 1574 7 44 3 94 0 53 1654 27 26 8 42 3 45 0 41 1526 8 17 3 35 0 41 1606 8 05 3 30 0 41 1654 7 81 3 20 0 41 1701 28 18 7 17 6 67 0 93 1272 6 86 6 38 0 93 1336 6 59 6 13 0 93 1399 6 34 5 90 0 93 1463 28 20 7 47 6 05 0 81 1336 7 17 5 81 0 81 1415 6 95 5 63 0 81 1447 6 71 5 44 0 81 1511 28 22 7 78 5 37 0 69 1383 7 50 5 18 0 69 1471 7 32 5 05 0...

Page 36: ...5 80 3 77 0 65 1844 27 24 7 02 3 72 0 53 1749 6 59 3 49 0 53 1829 6 22 3 30 0 53 1908 27 26 7 38 3 03 0 41 1813 6 95 2 85 0 41 1892 6 53 2 68 0 41 1972 28 18 5 98 5 56 0 93 1558 5 49 5 11 0 93 1654 5 06 4 71 0 93 1717 28 20 6 28 5 09 0 81 1622 5 86 4 74 0 81 1701 5 43 4 40 0 81 1797 28 22 6 65 4 59 0 69 1685 6 22 4 29 0 69 1781 5 80 4 00 0 69 1844 28 24 7 02 4 00 0 57 1749 6 59 3 76 0 57 1829 6 22...

Page 37: ...7 24 9 51 4 47 0 47 1829 9 16 4 30 0 47 1930 8 95 4 20 0 47 1990 8 66 4 07 0 47 2090 27 26 9 80 3 43 0 35 1930 9 51 3 33 0 35 2030 9 37 3 28 0 35 2090 9 09 3 18 0 35 2151 28 18 8 34 7 26 0 87 1608 7 99 6 95 0 87 1688 7 67 6 67 0 87 1769 7 38 6 42 0 87 1849 28 20 8 70 6 52 0 75 1688 8 34 6 26 0 75 1789 8 09 6 07 0 75 1829 7 81 5 86 0 75 1910 28 22 9 05 5 70 0 63 1749 8 73 5 50 0 63 1859 8 52 5 37 0...

Page 38: ...6 75 3 98 0 59 2332 27 24 8 17 3 84 0 47 2211 7 67 3 60 0 47 2312 7 24 3 40 0 47 2412 27 26 8 59 3 01 0 35 2291 8 09 2 83 0 35 2392 7 60 2 66 0 35 2492 28 18 6 96 6 05 0 87 1970 6 39 5 56 0 87 2090 5 89 5 13 0 87 2171 28 20 7 31 5 48 0 75 2050 6 82 5 11 0 75 2151 6 32 4 74 0 75 2271 28 22 7 74 4 88 0 63 2131 7 24 4 56 0 63 2251 6 75 4 25 0 63 2332 28 24 8 17 4 16 0 51 2211 7 67 3 91 0 51 2312 7 24...

Page 39: ...92 1118 3 62 1311 4 27 1445 4 97 1550 5 67 1624 6 32 1669 7 02 1714 MUZ AP50VG MUZ AP50VGH CAPACITY 5 8 kW INPUT 1600 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 3 65 1040 4 41 1248 5 16 1408 5 92 1520 6 67 1616 7 37 1664 8 12 1696 21 3 48 1120 4 18 1328 4 93 1472 5 63 1584 6 38 1664 7 08 1712 7 80 1776 26 3 13 1200 3 89 1408 4 58 1552 5 ...

Page 40: ...g 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 Ambient temperature thermistor Coo...

Page 41: ...d low load operation 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 interfere the start up of the compressor 2 If liquid refrigerant collects in the compressor a failure in the compressor may occur The pre h...

Page 42: ...l 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 check how many times the OPERATION INDIC...

Page 43: ... 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 failure mode recall function Release the failure mode recall functi...

Page 44: ...re 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 recall the fa...

Page 45: ...pressor 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 temperature Temperature of discharge temperature ther...

Page 46: ...ressor 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 thermist...

Page 47: ...ture P C board tem perature thermistor overheat protection Temperature of fin temperature thermistor on the heat sink exceeds 75 86 C MUZ AP25 35 42 50 60 75 80 C MUZ AP71 or temperature of P C board temperature thermis tor on the inverter P C board exceeds 72 85 C MUZ AP25 35 42 50 60 70 75 C MUZ AP71 Check around outdoor unit Check outdoor unit air passage Refer to 12 5 Check of outdoor fan moto...

Page 48: ...supply voltage is high MUZ AP71 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 12 5 Check of power supply 23 9 time blink 2 5 seconds OFF Inverter check mode The connector of compressor is disconnected inverter check mode starts Check if the connect...

Page 49: ...ing a tester Temperature 10 40 C Normal Ω MUZ AP25 35VG MUZ AP25 35VGH MUZ AP42 50 60VG MUZ AP42 50VGH MUZ AP71VG U V U W V W 1 59 2 16 0 82 1 11 0 87 1 18 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 AP25 35 42VG MUZ AP25 35 42VGH MUZ AP50 60VG MUZ AP50VGH MUZ AP71VG RED BLK BLK WHT WHT RED 32 43 1...

Page 50: ...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 51: ...asurement 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 10 seconds 10 minutes Judgement A...

Page 52: ...tance of thermistor MUZ AP25 35 42 50 60VG MUZ AP25 35 42 50VGH 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 MUZ AP71VG...

Page 53: ...00 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 12 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 V AC between CN60...

Page 54: ...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 55: ... 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 MUZ AP25 35 42 50 60VG MUZ AP25 35 42 50VGH 325 370 V DC between IC700 P and N MUZ AP71VG 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 pr...

Page 56: ...ester 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 Preparation of the...

Page 57: ...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 OBH789A ...

Page 58: ...ht up Replace the indoor electronic control P C board Yes Does the outdoor LED blink 6 times Yes Confirm that the thermostat is 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 Turn the power supply OFF Replace the indoor power P C board Start the emergency operation No Yes Yes Repair completed Does DC ...

Page 59: ...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 60: ...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 61: ...H MUZ AP42VGH MUZ AP50VGH Fin temperature thermistor 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 Smoothing capacitor C62 Output to drive compressor LDU LDV LDW Fuse F701 T3 15AL250V Fuse F61 25A 250V Fuse F62 15A 250V Smoothing capacitor C61 Fuse F901 T3 15AL250V R V coi...

Page 62: ...700 800 0 10 20 30 40 50 60 70 80 90 100110120 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 Expansion valve coil LEV CN724 Jumper wire for changing de...

Page 63: ... 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 2 types of the terminal with locking mechanism The terminal without locking mechanism can be...

Page 64: ...ove the cabinet 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 ...

Page 65: ...emove the inverter assembly Refer to section 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 as...

Page 66: ...e the service panel 5 Remove the top 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 66 Screws of the cabinet Screws of the top panel Screws of the cabinet Screws of the service panel Screw of the valve cover Screws...

Page 67: ...t the lead wires of the heat exchanger temperature thermistor the defrost thermistor and discharge tempera ture thermistor to the connector on the inverter P C board Pull the lead wires toward you and put them on the right hook on the P C board support 2 Connect the lead wires of the LEV to the connector on the inverter P C board Pull the lead wires toward you and put them on the right hook on the...

Page 68: ...Outdoor heat exchanger temperature thermistor 3 Pull out the discharge temperature thermistor from its holder 4 Pull out the defrost thermistor from its holder 5 Pull out the outdoor heat exchanger temperature thermistor from its holder 6 Pull out the ambient temperature thermistor from its holder 5 Removing outdoor fan motor 1 Remove the cabinet and panels Refer to section 1 2 Disconnect the foll...

Page 69: ...e 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 compressor nuts 6 Remove the compressor 7 Detach the brazed part of pipes connected with 4 way valve Photo 9 69 Brazed parts of 4 way valve Suction pipe brazed part Discharge pipe brazed part OBH789...

Page 70: ...p 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 70 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 pa...

Page 71: ... the lead wires of the inverter P C board 5 Remove the screws of the P B support 6 Remove the P B support from the relay panel 7 Remove the screws of the inverter P C board 8 Remove the inverter P C board from P B support Notes about attaching the inverter P C board 1 When attaching the inverter P C board clip the lead wires of the reactor to the wire saddles on the bottom of relay panel 2 After a...

Page 72: ...d wire to the reactor and the following connectors Inverter P C board CN671 Defrost thermistor discharge temperature thermis tor and outdoor heart exchanger temperature ther mistor CN672 Ambient temperature thermistor 3 Pull out the discharge temperature thermistor from its hold er Photo 9 4 Pull out the defrost thermistor from its holder 5 Pull out the outdoor heat exchanger temperature thermisto...

Page 73: ...1 2 Remove the back panel Refer to section 1 3 Remove the screws fixing the relay panel 4 Remove the relay panel 5 Remove the inverter assembly Refer to section 2 6 Recover gas from the refrigerant circuit NOTE Recover gas from the pipes until the pressure gauge shows 0 kg cm2 0 MPa 7 Detach the brazed part of the suction and the discharge pipe connected with compressor 8 Remove the compressor nut...

Page 74: ... 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Copyright 2017 MITSUBISHI ELECTRIC CORPORATION Issued Mar 2019 No OBH789 REVISED EDITION A Published Dec 2017 No OBH789 Made in Japan Specifications are subject to change without notice ...

Page 75: ...t MSZ AP25 50VG Declaration of Conformity CE2017B17 MSZ AP25 50VG K Install Manual JG79J601H01 MSZ AP25 50VGK Declaration of Conformity CE2017B18 MSZ AP25 50VGK DoC CE2020D01 MSZ AP25 50VGK DoC CE2021B03 MUZ AP25 71VG Parts List OBB789 A MUZ AP25 71VG Service Manual OBH789 A ...

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