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No. OBH839A

Indoor unit service manual

MSZ-AP•VG Series (OBH838)

PARTS CATALOG (OBB839A)

HFC

utilized

R32

SERVICE MANUAL

OUTDOOR UNIT

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 ··························7
6. OUTLINES AND DIMENSIONS ·····················8
7. WIRING DIAGRAM ·····································9
8. REFRIGERANT SYSTEM DIAGRAM ··········· 10
9. PERFORMANCE CURVES ························ 11

10. ACTUATOR CONTROL ····························· 18
11. SERVICE FUNCTIONS ······························ 19
12. TROUBLESHOOTING ······························· 20
13. DISASSEMBLY INSTRUCTIONS ················· 40

Models

MUZ-AP20VG

    

-

 

E1

 ,  

-

 

ET1

 ,  

-

 

ER1

MUZ-AP20VG   

OBH839 is void.

Revision A:

• MUZ-AP20VG-

ER1

 have been added.

Содержание MUZ-AP20VG

Страница 1: ...USING REFRIGERANT R32 3 3 PART NAMES AND FUNCTIONS 5 4 SPECIFICATION 6 5 NOISE CRITERIA CURVES 7 6 OUTLINES AND DIMENSIONS 8 7 WIRING DIAGRAM 9 8 REFRIGERANT SYSTEM DIAGRAM 10 9 PERFORMANCE CURVES 11 10 ACTUATOR CONTROL 18 11 SERVICE FUNCTIONS 19 12 TROUBLESHOOTING 20 13 DISASSEMBLY INSTRUCTIONS 40 Models MUZ AP20VG E1 ET1 ER1 MUZ AP20VG OBH839 is void Revision A MUZ AP20VG ER1 have been added ...

Страница 2: ...ant 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 used serviced or disposed of ...

Страница 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...

Страница 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...

Страница 5: ...5 Air outlet Drain outlet Piping Drain hose Air inlet Back and side MUZ AP20VG PART NAMES AND FUNCTIONS 3 ACCESSORIES MODELS MUZ AP20VG Drain socket 1 OBH839A ...

Страница 6: ...otor Model RC0J50 NC Current 1 Cooling A 0 22 Heating 0 20 Dimensions W H D mm 800 550 285 Weight kg 31 Special remarks Dehumidification Cooling L h 0 6 Airflow 1 Cooling High m3 h 2 178 Med 2 178 Low 1 038 Heating High 2 076 Med 1 788 Low 1 452 Sound level 1 Cooling dB A 47 Heating 48 Fan speed Cooling High rpm 940 Med 940 Low 470 Heating High 900 Med 780 Low 640 Fan speed regulator 3 Refrigerant...

Страница 7: ...V 12 V DC Reactor L61 18 mH Switch power transistor Q821 30 A 37 A 600 V Current limiting PTC thermistor PTC64 PTC65 33 Ω Terminal block TB1 5 P Relay X63 3 A 250 V X64 20 A 250 V X69 10 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 ...

Страница 8: ...8 Unit mm MUZ AP20VG OUTLINES AND DIMENSIONS 6 OBH839A ...

Страница 9: ...9 WIRING DIAGRAM 7 MUZ AP20VG E1 ET1 ER1 OBH839A ...

Страница 10: ...erature thermistor RT68 Stop valve with service port Muffler REFRIGERANT SYSTEM DIAGRAM 8 MUZ AP20VG Max Length A Max Height difference B Indoor unit Outdoor unit MAX REFRIGERANT PIPING LENGTH and MAX HEIGHT DIFFERENCE Model Refrigerant piping m Piping size O D mm Max Length A Max Height difference B Gas Liquid MUZ AP20VG 20 12 9 52 6 35 ADDITIONAL REFRIGERANT CHARGE R32 g Model Outdoor unit prech...

Страница 11: ...difference 1 Attach at least 2 sets of wet and dry bulb 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 o...

Страница 12: ...8 9 17 2 15 5 13 8 12 1 10 3 8 6 6 9 MUZ AP20VG Outdoor intake air Wet bulb temperature C 20 15 10 5 0 5 10 15 0 4 0 5 0 6 0 7 0 8 0 9 1 0 1 1 1 2 1 3 Heating capacity at Rated frequency Capacity correction factor 15 20 26 Indoor intake air Dry bulb temperature Indoor air Dry bulb temperature difference C 22 4 20 7 18 9 17 2 15 5 13 8 12 1 10 3 8 6 6 9 MUZ AP20VG Outdoor intake air Wet bulb temper...

Страница 13: ...or and outdoor unit are under the same temperature humidity condition Operation TEST 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...

Страница 14: ...VG Outdoor unit current 0 5 10 15 20 25 2 0 2 5 3 0 3 5 4 0 Ambient temperature C Outdoor current A MUZ AP20VG Outdoor unit current Condition Operation Test run operation Refer to 9 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 OBH839A ...

Страница 15: ...455 27 24 2 68 1 34 0 50 419 2 58 1 29 0 50 442 2 52 1 26 0 50 455 2 44 1 22 0 50 478 27 26 2 76 1 05 0 38 442 2 68 1 02 0 38 465 2 64 1 00 0 38 478 2 56 0 97 0 38 492 28 18 2 35 2 12 0 90 368 2 25 2 03 0 90 386 2 16 1 94 0 90 405 2 08 1 87 0 90 423 28 20 2 45 1 91 0 78 386 2 35 1 83 0 78 409 2 28 1 78 0 78 419 2 20 1 72 0 78 437 28 22 2 55 1 68 0 66 400 2 46 1 62 0 66 426 2 40 1 58 0 66 437 2 30 ...

Страница 16: ...515 1 90 1 18 0 62 534 27 24 2 30 1 15 0 50 506 2 16 1 08 0 50 529 2 04 1 02 0 50 552 27 26 2 42 0 92 0 38 524 2 28 0 87 0 38 547 2 14 0 81 0 38 570 28 18 1 96 1 76 0 90 451 1 80 1 62 0 90 478 1 66 1 49 0 90 497 28 20 2 06 1 61 0 78 469 1 92 1 50 0 78 492 1 78 1 39 0 78 520 28 22 2 18 1 44 0 66 488 2 04 1 35 0 66 515 1 90 1 25 0 66 534 28 24 2 30 1 24 0 54 506 2 16 1 17 0 54 529 2 04 1 10 0 54 552...

Страница 17: ...NPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT 15 1 58 377 1 90 452 2 23 510 2 55 551 2 88 586 3 18 603 3 50 615 21 1 50 406 1 80 481 2 13 534 2 43 574 2 75 603 3 05 621 3 36 644 26 1 35 435 1 68 510 1 98 563 2 30 603 2 63 632 2 93 650 3 25 667 NOTE Q Total capacity kW INPUT Total power input W DB Dry bulb temperature WB Wet bulb temperature OBH839A ...

Страница 18: ...The fan motor turns 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 protection Defrost thermistor Heating Defrosting Fin temperatur...

Страница 19: ...ere the start up 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 th...

Страница 20: ...thing capacitor 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 ...

Страница 21: ...oes the upper 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 ...

Страница 22: ...ilure 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...

Страница 23: ... 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 temperature Tem...

Страница 24: ...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...

Страница 25: ...efrig 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 outd...

Страница 26: ...unction 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...

Страница 27: ...m it up Refer to 12 6 Test 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 AP20VG U V U W V W 1 59 2 16 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 RED BLK BLK WHT WHT RED 32 4...

Страница 28: ...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...

Страница 29: ...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...

Страница 30: ... 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...

Страница 31: ... 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...

Страница 32: ...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...

Страница 33: ...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...

Страница 34: ...ge 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 P...

Страница 35: ...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 OBH839A ...

Страница 36: ...nuously 6 minutes after the emergency operation starts No Does the outdoor LED light 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 Replace the indoor electronic control P C boa...

Страница 37: ...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...

Страница 38: ...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...

Страница 39: ...VOLTAGE 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 F901 T3 15AL250V R V coil CN721 230 V AC Jumper wire for changing defrost setting JS Signal of outdoor...

Страница 40: ...s 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 Screws of the cabinet Hooks of the service panel Screw of the cabinet Screw of the service panel Indicates the visible parts in the photos figures Indicates the invisible parts in the photos figures 13 1 MUZ AP20VG NOTE Turn OFF the p...

Страница 41: ...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...

Страница 42: ...Remove 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 a...

Страница 43: ...43 OBH839A ...

Страница 44: ... 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Copyright 2019 MITSUBISHI ELECTRIC CORPORATION Issued Dec 2019 No OBH839 REVISED EDITION A Published Apr 2019 No OBH839 Made in Japan Specifications are subject to change without notice ...

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