Mitsubishi Electric MUZ-LN25VG Service Manual Download Page 15

Page: 15 / 68

Unit: mm

Outdoor

heat

exchanger

Flared connection

Defrost

thermistor

RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve

(with strainar)

Stop valve

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
cooling OFF

Strainer
#100

LEV

Ambient

temperature

thermistor

RT65

Muffler

Capillary tube
ø4.0×ø2.4×240

Outdoor heat

exchanger

temperature

thermistor

RT68

Strainer
#100

Muffler

REFRIGERANT SYSTEM DIAGRAM

Outdoor

heat

exchanger

Flared connection

Defrost

thermistor

RT61

Discharge
temperature
thermistor
RT62

Flared connection

Stop valve

(with strainar)

Stop valve

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
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

Strainer
#100

Muffler

MUZ-LN25VG MUZ-LN35VG

MUZ-LN50VG

OBH767

Summary of Contents for MUZ-LN25VG

Page 1: ... ER1 ET1 MUZ LN50VG E1 ER1 ET1 MUZ LN60VG E1 ER1 ET1 CONTENTS 1 TECHNICAL CHANGES 2 2 SERVICING PRECAUTIONS FOR UNITS USING REFRIGERANT R32 3 3 PART NAMES AND FUNCTIONS 5 4 SPECIFICATION 6 5 NOISE CRITERIA CURVES 9 6 OUTLINES AND DIMENSIONS 10 7 WIRING DIAGRAM 13 8 REFRIGERANT SYSTEM DIAGRAM 15 9 PERFORMANCE CURVES 17 10 ACTUATOR CONTROL 31 11 SERVICE FUNCTIONS 32 12 TROUBLESHOOTING 33 13 DISASSEM...

Page 2: ...sposed of Correct refrigerant is specified in the manuals and on the spec labels provided with our products We will not be held responsible for mechanical failure system malfunction unit breakdown or accidents caused by failure to follow the instructions MUZ LN25VG E1 ER1 ET1 MUZ LN35VG E1 ER1 ET1 MUZ LN50VG E1 ER1 ET1 MUZ LN60VG E1 ER1 ET1 1 New model TECHNICAL CHANGES 1 OBH767 ...

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: ...G MUZ LN35VG MUZ LN50VG MUZ LN60VG Drain socket 1 Piping Air outlet Drain outlet Air inlet back and side Drain hose 3 Air outlet Drain outlet Piping Drain hose Air inlet back and side MUZ LN60VG MUZ LN50VG Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH767 ...

Page 6: ...Model L 0 27 FW68S 0 35 FW68S Fan motor Model RC0J50 RB Current 1 Cooling A 0 26 0 26 Heating 0 22 0 25 Dimensions W H D mm 800 550 285 Weight kg 35 Special remarks Dehumidification Cooling L h 0 1 0 5 Air flow 1 Cooling High m3 h 2 124 Low 978 Heating High 2 028 Med 1 734 Low 1 302 Sound level 1 Cooling dB A 46 49 Heating 49 50 Fan speed Cooling High rpm 940 Low 460 Heating High 900 Med 780 Low 6...

Page 7: ...W68S Fan motor Model RC0J50 RA RC0J60 BC Current 1 Cooling A 0 29 0 84 Heating 0 29 0 84 Dimensions W H D mm 800 714 285 840 880 330 Weight kg 40 55 Special remarks Dehumidification Cooling L h 1 7 2 2 Air flow 1 Cooling High m3 h 2 748 3 006 Low 1 320 1 716 Heating High 2 622 3 006 Med 2 238 2 892 Low 1 704 2 280 Sound level 1 Cooling dB A 51 55 Heating 54 55 Fan speed Cooling High rpm 940 840 Lo...

Page 8: ...PTC65 33 Ω Terminal block TB1 5 P Relay X63 3 A 250 V X64 20 A 250 V X69 10 A 230 V R V coil 21S4 220 240 V AC Specifications and rated conditions of main electric parts Model Item MUZ LN60VG Smoothing capacitor CB1 CB2 CB3 560 μF 450 V Fuse F601 F880 F901 T3 15AL250 V Switching power transistor Q3A Q3B 21 A 650 V Power module IC932 5 A 600 V IC700 20 A 600 V Expansion valve coil LEV 12 V DC React...

Page 9: ...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 HEATING 55 55 MUZ LN25VG MUZ LN50VG MUZ LN60VG NOISE CRITERIA CURVES 5 Test conditions Cooling Dry bulb temperature 35 C Heating Dry bulb temperature 7 C Wet bulb temperature 6 C OUTDOO...

Page 10: ...10 OUTLINES AND DIMENSIONS 6 Unit mm MUZ LN25VG MUZ LN35VG OBH767 ...

Page 11: ...11 Unit mm MUZ LN50VG OBH767 ...

Page 12: ...rant 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 LN60VG Unit mm OBH767 ...

Page 13: ...13 WIRING DIAGRAM 7 MUZ LN25VG MUZ LN35VG MUZ LN50VG OBH767 ...

Page 14: ...14 MUZ LN60VG OBH767 ...

Page 15: ...xchanger temperature thermistor RT68 Strainer 100 Muffler REFRIGERANT SYSTEM DIAGRAM 8 Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared connection Stop valve with strainar Stop valve 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 i...

Page 16: ...0 g m Refrigerant piping length m 7 Model Outdoor unit precharged Refrigerant piping length one way 7 m 16 m 17 m 20 m 25 m 30 m MUZ LN60VG 1 450 0 180 200 260 360 460 Calculation X g 20 g m Refrigerant piping length m 7 Muffler 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...

Page 17: ...b thermometers 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 Ope...

Page 18: ...7 3 5 9 MUZ LN35VG 25 0 23 1 21 1 19 2 17 3 15 4 13 5 11 5 9 6 7 7 MUZ LN50VG 28 3 26 1 24 0 21 8 19 6 17 4 15 3 13 1 10 9 8 7 MUZ LN60VG 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 Indoor air Dry bulb temperature difference C 14 5 1...

Page 19: ...ency of compressor Hz Input correction factors MUZ LN50VG 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 Correction of Heating input The operationa...

Page 20: ...4 4 4 8 5 2 5 6 6 0 15 20 25 30 35 5 0 5 4 5 8 6 2 6 6 7 0 15 20 25 30 35 1 10 1 12 1 14 1 16 1 18 1 20 15 20 25 30 35 0 85 0 86 0 87 0 88 0 89 0 90 15 20 25 30 35 1 01 1 02 1 03 1 04 1 05 1 06 15 20 25 30 35 0 870 0 876 0 882 0 888 0 894 0 900 MUZ LN25VG 50 60 70 Ambient temperature C Ambient humidity Outdoor low pressure 11 0 11 2 11 6 11 8 12 0 11 4 kgf cm2 Gauge MPa Gauge MUZ LN60VG 50 60 70 A...

Page 21: ...door unit current Ambient temperature C Outdoor current A MUZ LN35VG Ambient temperature C Outdoor current A MUZ LN50VG Ambient temperature C Outdoor current A MUZ LN60VG Ambient temperature C Outdoor current A Condition Operation Test run operation Refer to 8 3 HEAT operation Indoor Outdoor Dry bulb temperature C 20 0 2 7 15 20 0 Wet bulb temperature C 14 5 1 6 12 14 5 OBH767 ...

Page 22: ... 480 27 24 3 35 2 24 0 67 441 3 23 2 16 0 67 466 3 15 2 11 0 67 480 3 05 2 04 0 67 504 27 26 3 45 1 90 0 55 466 3 35 1 84 0 55 490 3 30 1 82 0 55 504 3 20 1 76 0 55 519 28 18 2 94 2 94 1 00 388 2 81 2 81 1 00 407 2 70 2 70 1 00 427 2 60 2 60 1 00 446 28 20 3 06 2 91 0 95 407 2 94 2 79 0 95 432 2 85 2 71 0 95 441 2 75 2 61 0 95 461 28 22 3 19 2 65 0 83 422 3 08 2 55 0 83 449 3 00 2 49 0 83 461 2 88...

Page 23: ... 543 2 38 1 88 0 79 563 27 24 2 88 1 93 0 67 534 2 70 1 81 0 67 558 2 55 1 71 0 67 582 27 26 3 03 1 66 0 55 553 2 85 1 57 0 55 577 2 68 1 47 0 55 601 28 18 2 45 2 45 1 00 475 2 25 2 25 1 00 504 2 08 2 08 1 00 524 28 20 2 58 2 45 0 95 495 2 40 2 28 0 95 519 2 23 2 11 0 95 548 28 22 2 73 2 26 0 83 514 2 55 2 12 0 83 543 2 38 1 97 0 83 563 28 24 2 88 2 04 0 71 534 2 70 1 92 0 71 558 2 55 1 81 0 71 58...

Page 24: ... 812 27 24 4 69 2 81 0 60 746 4 52 2 71 0 60 787 4 41 2 65 0 60 812 4 27 2 56 0 60 853 27 26 4 83 2 32 0 48 787 4 69 2 25 0 48 828 4 62 2 22 0 48 853 4 48 2 15 0 48 877 28 18 4 11 4 11 1 00 656 3 94 3 94 1 00 689 3 78 3 78 1 00 722 3 64 3 64 1 00 754 28 20 4 29 3 77 0 88 689 4 11 3 62 0 88 730 3 99 3 51 0 88 746 3 85 3 39 0 88 779 28 22 4 46 3 39 0 76 713 4 31 3 27 0 76 759 4 20 3 19 0 76 779 4 03...

Page 25: ...18 3 33 2 39 0 72 951 27 24 4 03 2 42 0 60 902 3 78 2 27 0 60 943 3 57 2 14 0 60 984 27 26 4 24 2 03 0 48 935 3 99 1 92 0 48 976 3 75 1 80 0 48 1017 28 18 3 43 3 43 1 00 804 3 15 3 15 1 00 853 2 91 2 91 1 00 886 28 20 3 61 3 17 0 88 836 3 36 2 96 0 88 877 3 12 2 74 0 88 927 28 22 3 82 2 90 0 76 869 3 57 2 71 0 76 918 3 33 2 53 0 76 951 28 24 4 03 2 58 0 64 902 3 78 2 42 0 64 943 3 57 2 28 0 64 984...

Page 26: ...27 24 6 70 3 15 0 47 1256 6 45 3 03 0 47 1325 6 30 2 96 0 47 1366 6 10 2 87 0 47 1435 27 26 6 90 2 42 0 35 1325 6 70 2 35 0 35 1394 6 60 2 31 0 35 1435 6 40 2 24 0 35 1477 28 18 5 88 5 11 0 87 1104 5 63 4 89 0 87 1159 5 40 4 70 0 87 1214 5 20 4 52 0 87 1270 28 20 6 13 4 59 0 75 1159 5 88 4 41 0 75 1228 5 70 4 28 0 75 1256 5 50 4 13 0 75 1311 28 22 6 38 4 02 0 63 1201 6 15 3 87 0 63 1277 6 00 3 78 ...

Page 27: ...4 75 2 80 0 59 1601 27 24 5 75 2 70 0 47 1518 5 40 2 54 0 47 1587 5 10 2 40 0 47 1656 27 26 6 05 2 12 0 35 1573 5 70 2 00 0 35 1642 5 35 1 87 0 35 1711 28 18 4 90 4 26 0 87 1352 4 50 3 92 0 87 1435 4 15 3 61 0 87 1490 28 20 5 15 3 86 0 75 1408 4 80 3 60 0 75 1477 4 45 3 34 0 75 1559 28 22 5 45 3 43 0 63 1463 5 10 3 21 0 63 1546 4 75 2 99 0 63 1601 28 24 5 75 2 93 0 51 1518 5 40 2 75 0 51 1587 5 10...

Page 28: ...27 24 8 17 3 68 0 45 1629 7 87 3 54 0 45 1718 7 69 3 46 0 45 1772 7 44 3 35 0 45 1862 27 26 8 42 2 78 0 33 1718 8 17 2 70 0 33 1808 8 05 2 66 0 33 1862 7 81 2 58 0 33 1915 28 18 7 17 6 09 0 85 1432 6 86 5 83 0 85 1504 6 59 5 60 0 85 1575 6 34 5 39 0 85 1647 28 20 7 47 5 45 0 73 1504 7 17 5 23 0 73 1593 6 95 5 08 0 73 1629 6 71 4 90 0 73 1701 28 22 7 78 4 74 0 61 1557 7 50 4 58 0 61 1656 7 32 4 47 ...

Page 29: ...5 79 3 30 0 57 2076 27 24 7 01 3 16 0 45 1969 6 59 2 96 0 45 2059 6 22 2 80 0 45 2148 27 26 7 38 2 44 0 33 2041 6 95 2 29 0 33 2130 6 53 2 15 0 33 2220 28 18 5 98 5 08 0 85 1754 5 49 4 67 0 85 1862 5 06 4 30 0 85 1933 28 20 6 28 4 59 0 73 1826 5 86 4 27 0 73 1915 5 43 3 96 0 73 2023 28 22 6 65 4 06 0 61 1897 6 22 3 80 0 61 2005 5 79 3 53 0 61 2076 28 24 7 01 3 44 0 49 1969 6 59 3 23 0 49 2059 6 22...

Page 30: ...2 68 704 3 16 776 3 68 832 4 20 872 4 68 896 5 20 920 MUZ LN50VG CAPACITY 6 0 kW INPUT 1480 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 78 962 4 56 1154 5 34 1302 6 12 1406 6 90 1495 7 62 1539 8 40 1569 21 3 60 1036 4 32 1228 5 10 1362 5 82 1465 6 60 1539 7 32 1584 8 07 1643 26 3 24 1110 4 02 1302 4 74 1436 5 52 1539 6 30 1613 7 02 1658...

Page 31: ...s OFF 15 seconds after 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 Discharge temperature thermistor Protection Indoor coil temperature thermistor Cooling Coil frost prevention Heating High pressure protec tion Defrost thermistor Heating Defrosting Fin temperature thermistor Prot...

Page 32: ...W MUZ LN60 Prolonged 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 startup of the compressor 2 If liquid refrigerant collects in the compressor a failure in the compressor m...

Page 33: ...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 flashing on and off to indicate an abnormality To make sure che...

Page 34: ...ndoor unit is abnormal Check the blinking pattern and identify the abnormal point by referring to the indoor unit failure recall mode table Refer to indoor unit service manual Make sure to check at least two consecutive blinking cycles 2 Releasing the failure mode recall function Release the failure mode recall function by the following procedures Turn OFF the power supply and turn it ON again Pre...

Page 35: ...ion 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 acc...

Page 36: ...mpressor synchronous abnormality Compressor startup failure protection 12 time flash 2 5 seconds OFF Waveform of compressor current is distorted Reconnect compressor connector Refer to 12 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...

Page 37: ...rrent of compressor cannot be detected normally 14 time flash or more 2 5 seconds OFF Stop valve Closed valve 14 time flash 2 5 seconds OFF Closed valve is detected by compressor current Check stop valve 4 way valve Pipe temperature 16 time flash 2 5 seconds OFF The 4 way valve does not work properly The indoor coil thermistor detects an abnormal temperature Check the 4 way valve Replace the inver...

Page 38: ...re P C board tem perature thermistor overheat protection Temperature of fin temperature thermistor on the heat sink ex ceeds 75 86 C LN25 35 50 75 80 C LN60 or tempera ture of P C board temperature thermistor on the inverter P C board exceeds 72 85 C LN25 35 50 70 75 C LN60 Check around outdoor unit Check outdoor unit air passage Refer to 12 5 Check of outdoor fan motor 12 5 time flash 2 5 seconds...

Page 39: ... the power supply voltage is high MUZ LN60 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 flash 2 5 seconds OFF Inverter check mode The connector of compressor is disconnected inverter check mode starts Check if ...

Page 40: ... point 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 LN25VG MUZ LN35VG MUZ LN50VG MUZ LN60VG U V U W V W 1 59 2 16 1 60 2 17 0 82 1 11 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 MUZ LN25 ...

Page 41: ...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 42: ...efer 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 10 seconds 10 minut...

Page 43: ...sure the resistance of thermistor MUZ LN25 35 50VG 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 LN60VG Thermistor S...

Page 44: ...GBT 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 V A...

Page 45: ...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 46: ...oard light up or flash 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 LN25 35 50VG 325 370 V DC between IC700 P and N MUZ LN60VG 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 E...

Page 47: ... 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 Prepar...

Page 48: ...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 flash 10 times Replace the inverter P C board Check the corresponding parts following LED indication Refer to 12 3 Yes No Yes 10 time flash No L Check of inverter P C board OBH767 ...

Page 49: ...OWER lamp blink continuously 6 minutes after the emergency operation starts No Does the outdoor LED light up Replace the indoor electronic control P C board Replace the indoor electronic control P C board Replace the indoor power P C board Yes 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 b...

Page 50: ...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 51: ...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 52: ... 80 90 100110120 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 VAC Smoothing capacitor C62 Smoothing capacitor C63 Output to drive compressor LDU LDV LDW Fuse F701 T3 15AL250V Smoothing capacitor C61 LN50VG Fuse F901 T3 15AL250V R V coil CN721 230 V A...

Page 53: ... 400 500 600 700 800 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 LEV CN724 Jumper wire for changing defrost se...

Page 54: ... lever or not 2 The terminal with this connector has the locking mechanism Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pull out the terminal slowly Connector Sleeve Locking lever 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 Di...

Page 55: ...ure when attaching the inverter P C board Photo 5 1 Connect the lead wires of the heat exchanger temperature thermistor to the connector on the inverter P C board Pull the lead wires of the heat exchanger temperature thermis tor toward you and put them on the left hook on the P C board support so that the other lead wires are bundled up as shown in Photo 5 2 Connect the lead wires of the expansion...

Page 56: ...istor 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 an...

Page 57: ...ecover 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 57 Brazed parts of 4 way valve Suction pipe brazed part Discharge pipe brazed part Discharge temperature thermistor O...

Page 58: ...over 7 Disconnect the power supply and indoor outdoor connect ing wire and the demand control signal transmission cable 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 58 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 Scr...

Page 59: ...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 P C board support 3 Con...

Page 60: ... 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 1 2 Disconnect the following connector...

Page 61: ...t 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 61 Brazed parts of 4 way valve Suction pipe brazed part Discharge pipe brazed part OBH767 ...

Page 62: ...over 7 Disconnect the power supply and indoor outdoor connect ing wire and the demand control signal transmission cable 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 62 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 Scr...

Page 63: ...d 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 attaching...

Page 64: ...he 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 thermistor from its ...

Page 65: ... Remove the back panel Refer to 1 3 Remove the screws fixing the relay panel 4 Remove the relay panel 5 Remove the inverter assembly Refer to 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 nuts 9 Remove the comp...

Page 66: ...ht 2016 MITSUBISHI ELECTRIC CORPORATION Published Dec 2016 No OBH767 Made in Japan Specifications are subject to change without notice HEAD OFFICE TOKYO BUILDING 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN ...

Page 67: ...Installation Manual JG79B784H15 MSZ LN18VGK MSZ LN20VGK MSZ LN25VGK MSZ LN35VGK MSZ LN50VGK MSZ LN60VGK MUZ LN25VG MUZ LN35VG MUZ LN5 VG MUZ LN6 VG DOC 2021B50 MSZ LN25 60VG Declaration of Conformity CE2017B30 MUZ LN25 60VG Parts Catalogue OBB767 MUZ LN25 60VG Service Manual OBH767 ...

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