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19

TROUBLESHOOTING

11

11-1. Cautions on troubleshooting

1. Before troubleshooting, check the following: 
(1) Check the power supply voltage.
(2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care the following during service.
(1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, and then after

confirming the horizontal vane has completely closed, turn off the breaker.

(2) Be sure to unplug the power cord before removing the air inlet grille, the front panel, the cabinet, the top panel and 

the electronic control P.C. boards.

(3) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the

components.

(4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.

3. Troubleshooting procedure
(1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.

To make sure, check how many times the abnormality indication is flashing on and off before starting service work.

(2) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and

the components for bursting and discoloration.

(3) When troubleshooting, refer to the flow chart and the check table on page 20 and 21.

MUCFH-A18WV -

MUCFH-A24WV -

E1

E1

OB337B--1.qxp  05.7.6 11:00 AM  Page 19

Содержание MUCFH-A18WV-E1

Страница 1: ...AM 8 7 REFRIGERANT SYSTEM DIAGRAM 9 8 PERFORMANCE CURVES 10 9 ACTUATOR CONTROL 18 10 SERVICE FUNCTIONS 18 11 TROUBLESHOOTING 19 12 DISASSEMBLY INSTRUCTIONS 29 13 PARTS LIST 33 MUCFH A18WV E1 Indication of model name NOTE This service manual describes technical data of outdoor units As for indoor units MCFH A18WV and MCFH A24WV refer to the service manual OB336 E1 E1 HFC utilized R410A Revision B P...

Страница 2: ...sed on CO2 INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT This room air conditioner adopts an HFC refrigerant R410A which never destroys the ozone layer Pay particular attention to the following points though the basic installation procedure is same as that for R22 conditioners 1 As R410A has working pressure approximate 1 6 times as high as that of R22 some special tools and piping pa...

Страница 3: ...detector R410A has high pressures beyond the measurement range of existing gauges Port diameters have been changed to prevent any other refrigerant from being charged into the unit Hose material and cap size have been changed to improve the pressure resistance Dedicated for HFC refrigerant 6 35 mm and 9 52 mm Description Clamp bar hole has been enlarged to reinforce the spring strength in the tool...

Страница 4: ... the vacuum pump for air purging for the purpose of environmental protection 5 Additional charge For additional charging charge the refrigerant from liquid phase of the gas cylinder If the refrigerant is charged from the gas phase composition change may occur in the refrigerant inside the cylinder and the outdoor unit In this case ability of the refrigerating cycle decreases or normal operation ca...

Страница 5: ...el Thermistor RT61 at 0 kW r h K h A A W A A A W mm kg dB rpm kg cc k MUCFH A18WV E1 Single phase 230V 50Hz 2 196 15 94 37 0 39 RN196VHSHT 1 300 C R 1 80 C S 3 00 RA6V50 OG WHT BLK 116 BLK RED 111 850o605o290 47 52 828 1 1 85 520 NEO22 33 18 Cooling 4 8 2 4 8 01 1 730 7 62 2 65 Heating 5 0 8 38 1 810 7 99 2 65 MUCFH A24WV E1 Single phase 230V 50Hz 2 760 25 98 74 0 58 NN29VBAHT 1 900 C R 0 80 C S 1...

Страница 6: ...ry bulb temperature 35 Wet bulb temperature 24 Heating Dry bulb temperature 7 Wet bulb temperature 6 MUCFH A24WV E1 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 APPROXIMATE THRESHOLD OF HEARING FOR CONTINUOUS NOISE High FAN SPEED 53 SPL dB A LINE Test conditions C...

Страница 7: ... 157 74 850 500 183 20 292 605 248 35 350 50 290 310 345 20 355 90 Drainage hole 16 2 3 0 3 5 155 90 198 40 515 299 66 34 51 330 360 850 430 500 80 121 840 Open as a rule 500mm or more if the front and both sides are open 100mm or more 200mm or more if there are obstacles to both sides Open as a rule 500mm or more if the back both sides and top are open 350mm or more 100mm or more Liquid refrigera...

Страница 8: ... INNER PROTECTOR VARISTOR DEFROST THERMISTOR SOLID STATE RELAY TERMINAL BLOCK TERMINAL BLOCK TRANSFORMER CONTACTOR R V COIL RELAY R V COIL COMPRESSOR CONTACTOR MUCFH A18WV E1 MODEL WIRING DIAGRAM OUTDOOR UNIT MC CN661 3 1 2 CN721 21S4 MF SR62 SR61 TAB20 GRN YLW BLU CIRCUIT BREAKER POWER SUPPLY BLU BRN DSAR BLK BRN RED DEICER P C BOARD 4 C1 BLK RED 3 WHT S C R CN730 RT61 BLK 2 3 1 RED WHT 12V TO CO...

Страница 9: ...ow in cooling Refrigerant flow in heating Oil separator 100 4 way valve MUCFH A24WV E1 OUTDOOR UNIT Refrigerant pipe 15 88 with heat insulator Flared connection Flared connection Refrigerant pipe 6 35 with heat insulator Stop valve Receiver Check valve Capillary tube 3 0X 2 0X800 Defrost thermistor RT61 Compressor Stop valve with service port Outdoor heat exchanger Refrigerant flow in cooling Refr...

Страница 10: ...Operating conditions vary according to the areas where these units are installed The following information has been provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve 1 GUARANTEED VOLTAGE 198 264V 50Hz 2 AIR FLOW Air flow should be set at MAX 3 MAIN READINGS COOLING 1 Indoor intake air wet bulb temperature CWB 2 Indoor o...

Страница 11: ...s 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 inlet Cover the thermometers to prevent direct rays of the sun 3 Check that the air filter is cleaned 4 Open windows and doors of the room 5 Press the EMERGENCY OPERATION switch once twice to start the EMERGENCY COOL HEAT ...

Страница 12: ...ge MUCFH A18WV E1 HEAT operation Condition Indoor Dry bulb temerature 20 0 Outdoor Dry bulb temerature 7 15 20 Outdoor unit current A 5 7 10 15 20 25 16 15 14 13 12 11 11 10 9 8 230V Outdoor unit current A 5 7 10 15 20 25 230V Wet bulb temerature 6 12 14 5 Wet bulb temerature 14 5 50 60 70 Ambient temperature Ambient humidity 50 60 70 Ambient temperature Ambient humidity 1 1 1 0 0 9 0 8 0 7 0 6 0 ...

Страница 13: ... 23 1882 6 14 1 41 0 23 1937 28 18 5 64 4 23 0 75 1448 5 40 4 05 0 75 1520 5 18 3 89 0 75 1593 4 99 3 74 0 75 1665 28 20 5 88 3 70 0 63 1520 5 64 3 55 0 63 1611 5 47 3 45 0 63 1647 5 28 3 33 0 63 1720 28 22 6 12 3 12 0 51 1575 5 90 3 01 0 51 1674 5 76 2 94 0 51 1720 5 52 2 82 0 51 1792 28 24 6 43 2 51 0 39 1647 6 19 2 41 0 39 1738 6 05 2 36 0 39 1792 5 86 2 28 0 39 1882 28 26 6 62 1 79 0 27 1738 6...

Страница 14: ... 23 2154 5 30 1 22 0 23 2199 28 18 4 70 3 53 0 75 1774 4 32 3 24 0 75 1882 4 15 3 11 0 75 1919 28 20 4 94 3 11 0 63 1846 4 61 2 90 0 63 1937 4 44 2 80 0 63 1991 28 22 5 23 2 67 0 51 1919 4 90 2 50 0 51 2027 4 73 2 41 0 51 2063 28 24 5 52 2 15 0 39 1991 5 18 2 02 0 39 2082 5 04 1 97 0 39 2127 28 26 5 81 1 57 0 27 2063 5 47 1 48 0 27 2154 5 30 1 43 0 27 2199 29 18 4 70 3 72 0 79 1774 4 32 3 41 0 79 ...

Страница 15: ... 22 2548 7 68 1 69 0 22 2622 28 18 7 05 5 22 0 74 1960 6 75 5 00 0 74 2058 6 48 4 80 0 74 2156 6 24 4 62 0 74 2254 28 20 7 35 4 56 0 62 2058 7 05 4 37 0 62 2181 6 84 4 24 0 62 2230 6 60 4 09 0 62 2328 28 22 7 65 3 83 0 50 2132 7 38 3 69 0 50 2266 7 20 3 60 0 50 2328 6 90 3 45 0 50 2426 28 24 8 04 3 06 0 38 2230 7 74 2 94 0 38 2352 7 56 2 87 0 38 2426 7 32 2 78 0 38 2548 28 26 8 28 2 15 0 26 2352 8...

Страница 16: ... 22 2916 6 63 1 46 0 22 2977 28 18 5 88 4 35 0 74 2401 5 40 4 00 0 74 2548 5 19 3 84 0 74 2597 28 20 6 18 3 83 0 62 2499 5 76 3 57 0 62 2622 5 55 3 44 0 62 2695 28 22 6 54 3 27 0 50 2597 6 12 3 06 0 50 2744 5 91 2 96 0 50 2793 28 24 6 90 2 62 0 38 2695 6 48 2 46 0 38 2818 6 30 2 39 0 38 2879 28 26 7 26 1 89 0 26 2793 6 84 1 78 0 26 2916 6 63 1 72 0 26 2977 29 18 5 88 4 59 0 78 2401 5 40 4 21 0 78 ...

Страница 17: ...85 1871 5 50 1966 6 10 2022 6 73 2098 26 2 70 1418 3 35 1663 3 95 1833 4 60 1966 5 25 2060 5 85 2117 6 50 2174 CAPACITY 6 8 KW INPUT 2720 W OUTDOOR WB INDOOR 10 5 0 5 10 15 20 DB Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT 15 4 28 1768 5 17 2122 6 05 2394 6 94 2584 7 82 2747 8 64 2829 9 52 2883 21 4 08 1904 4 90 2258 5 78 2502 6 60 2693 7 48 2829 8 30 2910 9 15 3019 26 3 67 2040 4 56 2...

Страница 18: ...er to page 27 or 28 E1 MUCFH A18WV E1 MUCFH A24WV Jumper wire JRF JRG Model Change point Defrost interval time changes from 40 minutes to 15 minutes Defrost start temperature changes from 3 to 0 MUCFH A18WV Defrost start temperature does not change 3 0 MUCFH A24WV Defrost finish temperature changes from 3 1 to 10 1 MUCFH A18WV Defrost finish temperature changes from 3 1 to 15 MUCFH A24WV MUCFH A18...

Страница 19: ...boards 3 When removing the electronic control P C board hold the edge of the board with care NOT to apply stress on the components 4 When connecting or disconnecting the connectors hold the housing of the connector DO NOT pull the lead wires 3 Troubleshooting procedure 1 First check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality To make sure ch...

Страница 20: ...rval Cause Indoor Outdoor unit Mis wiring or trouble of serial signal 2 time flash Cause Indoor unit Trouble of room temperature indoor coil thermistor Check room temperature thermistor and indoor coil thermistor Refer to Test point diagram and voltage 4 time flash Cause Indoor unit Trouble of indoor electric control P C board Refer to Check of indoor electric control P C board Refer to B How to c...

Страница 21: ...al Open or short circuit 102 126Ω 97 120Ω MUCFH A18WV WHT BLK BLK RED Abnormal Open or short circuit MUCFH A18WV BLK REDORNWHT MAIN AUX P INNER PROTECTOR P MUCFH A24WV 0 84 1 04Ω 1 82 2 24Ω 55 68Ω MUCFH A24WV BLK YLW YLW RED 26 33Ω 55 68Ω MUCFH A24WV BLK YLWRED ORN WHT MAIN AUX 2 AUX 1 P Defrost thermistor RT61 Measure the resistance with a tester Part temperature 10 C 40 C Normal 5kΩ 60kΩ Abnorma...

Страница 22: ...ssor capacitor Refer to page 21 Yes Is there 230V AC between 4 on the compressor contactor 52C and TAB20 on the deicer P C board Is there 230V AC between L N on the outdoor terminal block TB1 Replace the deicer P C board Replace the deicer P C board No No Yes Yes No Check the outdoor fan motor Refer to page 21 Is there 230V AC between 4 on the compressor contactor 52C and TAB 20 on the deicer P C ...

Страница 23: ...tart Yes Is there 230V AC between 2 T1 on the compressor contactor 52C and N on the outdoor terminal block Yes Is there 230V AC between CN730 1 3 on the deicer P C board w1 Replace the deicer P C board Replace the deicer P C board No Yes No Is there 230V AC between 1 L1 on the compressor contactor 52C and N on the outdoor terminal block No No Make the connection of wiring correct Yes Yes Is there ...

Страница 24: ...OPERATION is there 10V DC between both ends of R601 on the deicer P C board By tester the stylus is between 5 10V Replace the deicer P C board Rectify indoor outdoor unit connecting wire Check and rectify fuse and varistor on the deicer P C board Rectify indoor outdoor unit connecting wire Replace the indoor electronic control P C board w 1 Short circuit of JPG and JPS on the electronic control P ...

Страница 25: ... Yes Yes No After 3 minutes does the unit operate in HEAT mode Ok No Replace the deicer P C board No Replace the R V coil Disconnect the TAB52 on the deicer P C board MUCFH A24WV Turn ON the power supply and operate the indoor unit in HEAT mode by pressing the EMERGENCY OPERATION switch Replace the deicer P C board Yes Yes No Replace the R V coil Is there 230V AC between CN7211 2 MUCFH A18WV CN721...

Страница 26: ...ave the characteristics on page 27 or 28 No Yes Does the unit operate 10 minutes or more Replace the deicer P C board Ok W1 W1 It is thought defective contact of the connector Turn OFF the power supply Defrost thermistor RT61 w Disconnect the connectors CN661 from the deicer P C board Check the characteristics of each thermistor E When OPERATION INDICATOR lamp flashes 6 time Thermistors in the out...

Страница 27: ...1 Fuse 2A 250V CN661 1 2 Defrost thermistor RT61 Refer to page 26 12V DC J204 J101 R601 5 10V DC 5V DC J205 J101 Power supply input 230V AC NR61 Varistor Jumper wire for change in defrost setting JRF JRG Refer to page 18 Defrost interval time short pin JPDS JPSG Refer to page 18 Refer to page 22 or 24 ...

Страница 28: ...defrost setting JRF JRG Refer to page 18 5V DC CN661 1 2 Defrost thermistor RT61 Refer to page 26 Defrost thermistor RT61 20 10 0 10 20 30 40 0 10 20 30 40 50 60 70 80 90 100 Temperature Resistance k Fan motor CN711 230V Varistor NR61 Refer to page 23 or 24 J101 J401 R V coil CN721 230V Power sup ply input CN7301 3 230V AC R601 10V DC Refer to page 24 Refer to page 23 ...

Страница 29: ...d by pulling it out Check the shape of the terminal and work Terminal with lock mechanism Detaching points Connector Sleeve Locking lever OPERATING PROCEDURE PHOTOS 1 Removing the cabinet 1 Remove the screws of the cabinet 2 Hold the down of the cabinet on the both side and remove the cabinet 2 Removing the deicer P C board 1 Remove the service panel and the cabinet 2 Disconnect all the connectors...

Страница 30: ... on the propeller 3 Remove the clamp of outdoor fan motor lead wire and disconnect the outdoor fan motor connector 4 Remove the screws fixing the outdoor fan motor 5 Remove the outdoor fan motor 4 Removing the compressor 1 Remove the cabinet Refer to 1 2 Remove the relay panel 3 Remove the soundproof felt 4 Remove the terminal cover on the compressor 5 Disconnect lead wires from the compressor 6 R...

Страница 31: ...anel 10 Remove the back panel Photo 2 Photo 1 Photo 3 Screw of the top panel Screws of the cabinet Screws of the cabinet Screws of the top panel Screw of the motor support Set screws of the back panel Screws of the front panel 2 Removing the deicer P C board 1 Remove the service panel and the cabinet 2 Disconnect all the connectors and the terminals on the deicer P C board 3 Remove the deicer P C ...

Страница 32: ... outdoor fan motor 5 Remove the outdoor fan motor Photo 5 Set screws of the outdoor fan motor Set screws of the outdoor fan motor Propeller nut 4 Removing the compressor 1 Remove the cabinet Refer to 1 2 Remove the relay panel 3 Remove the soundproof felt 4 Remove the terminal cover on the compressor 5 Disconnect lead wires from the compressor 6 Recover gas from the refrigerant circuit 7 Disconnec...

Страница 33: ... WAY VALVE COMPRESSOR CAPACITOR OUTDOOR FAN MOTOR SURGE ABSORBER DEICER P C BOARD TERMINAL BLOCK TERMINAL BLOCK DEFROST THERMISTOR HANDLE CAPILLARY TUBE CAPILLARY TUBE CAPILLARY TUBE CAPILLARY TUBE FUSE R V COIL CHECK VALVE VARISTOR MC C1 MF DSAR TB1 TB2 RT61 F61 21S4 NR61 3RUBBERS SET RN196VHSHT 12 7 6 35 40 440V AC RA6V50 3P 2P 3 0 1 6 750 3 0 1 6 650 3 0 1 6 500 2 5 0 6 1000 250V 2A No 1 1 1 1 ...

Страница 34: ...34 MUCFH A24WV 13 3 OUTDOOR UNIT STRUCTURAL PARTS ELECTRICAL PARTS AND FUNCTIONAL PARTS E1 3 23 16 12 1 15 13 14 2 4 5 6 7 8 9 10 11 17 18 19 20 21 22 24 25 26 27 32 33 13 4 ACCESSORY ...

Страница 35: ...25 26 27 28 29 30 31 TOP PANEL OUTDOOR HEAT EXCHANGER OUTDOOR FAN MOTOR PROPELLER BASE CABINET HANDLE FAN GUARD 4 WAY VALVE R V COIL DEFROST THERMISTOR COMPRESSOR RUBBER SET COMPRESSOR STOP VALVE GAS STOP VALVE LIQUID VALVE COVER SERVICE PANEL SURGE ABSORBER TERMINAL BLOCK TERMINAL BLOCK OUTDOOR FAN CAPACITOR DEICER P C BOARD COMPRESSOR CONTACTOR COMPRESSOR CAPACITOR BACK PANEL OUT HANDLE MOTOR SU...

Страница 36: ...opyright 2004 MITSUBISHI ELECTRIC ENGINEERING CO LTD Distributed in Jul 2005 No OB337 REVISED EDITION B 6 Distributed in Apr 2004 No OB337 REVISED EDITION A 6 Distributed in Feb 2004 No OB337 6 Made in Japan HEAD OFFICE MITSUBISHI DENKI BLDG 2 2 3 MARUNOUCHI CHIYODA KU TOKYO100 8310 JAPAN ...

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