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Mitsubishi Electric MUZ-HM09NA-U1, Service Manual, Page: 17 / 66

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Mitsubishi Electric MUZ-HM09NA-U1 Service Manual Download Page 17

17

Unit: Inch (mm)

MUZ-HM24NA   MUZ-HM24NA2

Outdoor

heat

exchanger

Flared connection

Defrost
thermistor
RT61

Discharge

temperature

thermistor

RT62

Flared connection

Stop valve

Capillary tube
O.D. 0.157× 
I.D. 0.094× 
3-15/16

(ø4.0×ø2.4×100)

Capillary tube

O.D. 0.157×
I.D. 0.094×7-7/8

(ø4.0×ø2.4×200)

Refrigerant flow in cooling

Compressor

4-way 
valve

Refrigerant flow in heating

Refrigerant pipe ø5/8 (ø15.88)
(with heat insulator)

Refrigerant pipe ø3/8 (ø9.52)
(with heat insulator)

LEV

R.V. coil
heating ON
cooling OFF

Muffler
with #100 mesh strainer

Strainer

#100

Outdoor heat 
exchanger 
temperature
thermistor
RT68

Strainer

#100

Muffler

Capillary tube
O.D. 0.118× 
I.D. 0.079× 7-7/8
(ø3.0×ø2.0×200(×4))

Stop valve
(with service port)

Service

port

Service port

OBH747C

Summary of Contents for MUZ-HM09NA-U1

Page 1: ...INDOOR UNIT SERVICE MANUAL OUTDOOR UNIT No OBH747 REVISED EDITION C OBH747 REVISED EDITION B is void Revision C MUZ HM09 12NA U1 MUZ HM09 12NA2 U1 have been added Indoor unit service manual MSZ HM NA Series OBH746 CONTENTS 1 TECHNICAL CHANGES 3 2 PART NAMES AND FUNCTIONS 4 3 SPECIFICATION 5 4 OUTLINES AND DIMENSIONS 10 5 WIRING DIAGRAM 12 6 REFRIGERANT SYSTEM DIAGRAM 15 7 DATA 19 8 ACTUATOR CONTRO...

Page 2: ...nuals 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 Revision A MUZ HM09 12NA U8 MUZ HM09 12NA2 U8 MUZ HM15 18NA U1 MUZ HM15 18NA2 U1 and MUZ HM24NA2 U1 have been added Revision B 3 SPECIFICATION has been modified Revision C MUZ HM09 12NA U1 MUZ HM09...

Page 3: ...U1 1 New model MUZ HM09NA U8 MUZ HM09NA2 U8 MUZ HM12NA U8 MUZ HM12NA2 U8 MUZ HM15NA U1 MUZ HM15NA2 U1 MUZ HM18NA U1 MUZ HM18NA2 U1 MUZ HM24NA2 U1 1 New model MUZ HM09NA U1 MUZ HM09NA2 U1 MUZ HM12NA U1 MUZ HM12NA2 U1 1 New model OBH747C ...

Page 4: ...t Drain outlet Air inlet back and side Drain hose PART NAMES AND FUNCTIONS 2 MUZ HM09NA MUZ HM09NA2 MUZ HM12NA MUZ HM12NA2 MUZ HM15NA MUZ HM15NA2 MUZ HM18NA MUZ HM18NA2 Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH747C ...

Page 5: ...eration oil fl oz L Model 9 1 0 27 FV50S 10 8 0 32 NEO22 Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 46 Heating dB A 50 Airflow High Med Low Cooling CFM 1 063 Heating CFM 1 282 1 105 1 240 1 105 Fan speed High Med Low Cooling rpm 740 Heating rpm 890 770 860 770 Defrost method Reverse cycle Dimensions W in 31 1 2 D in 11 1 4 H in 21 5 8 Weight Ib 73 External finish Munsell...

Page 6: ...l oz L Model 9 1 0 27 FV50S 10 8 0 32 NEO22 Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 49 Heating dB A 51 Airflow High Med Low Cooling CFM 1 063 1 102 639 Heating CFM 1 282 1 105 1 186 1 116 1 045 Fan speed High Med Low Cooling rpm 740 810 490 Heating rpm 890 770 870 820 770 Defrost method Reverse cycle Dimensions W in 31 1 2 D in 11 1 4 H in 21 5 8 Weight Ib 73 External...

Page 7: ...il fl oz L Model 11 8 0 35 FV50S 11 8 0 35 FV50S Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 49 49 Heating dB A 51 51 Airflow High Med Low Cooling CFM 1 102 639 1 102 639 Heating CFM 1 186 1 045 1 045 1 186 1 045 1 045 Fan speed High Med Low Cooling rpm 810 490 810 490 Heating rpm 870 770 770 870 770 770 Defrost method Reverse cycle Dimensions W in 31 1 2 31 1 2 D in 11 1...

Page 8: ... oil fl oz L Model 11 8 0 35 FV50S Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 54 Heating dB A 55 Airflow High Med Low COOL CFM 1 742 922 HEAT CFM 1 691 1 691 1 372 Fan speed High Med Low Cooling rpm 840 450 Heating rpm 810 810 650 Defrost method Reverse cycle Dimensions W in 33 1 16 D in 13 H in 34 5 8 Weight Ib 121 External finish Munsell 3Y 7 8 1 1 Refrigerant piping N...

Page 9: ...d 70 60 17 15 H0 1 Heating Steady State at minimum compressor Speed 70 60 62 56 5 H1 1 Heating Steady State at minimum compressor Speed 70 60 47 43 H2 V Heating at Intermediate compressor Speed 5 70 60 35 33 5 At Intermediate compressor Speed Rated compressor speed minimum compressor speed 3 minimum compressor speed 3 4 2 OPERATION Mode Condition Intake air temperature F Indoor Outdoor DB WB DB WB...

Page 10: ...m or more Liquid refrigerant pipe joint Refrigerant pipe flared Ø 1 4 Gas refrigerant pipe joint Refrigerant pipe flared Ø 3 8 HM09 12 Ø 1 2 HM15 18 REQUIRED SPACE clear 1 1 4 in 100 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 holes MUZ HM15NA MUZ HM15NA2 MUZ HM18NA MUZ HM18NA2 OBH747C ...

Page 11: ...3 29 32 6 1 2 7 11 16 3 5 4 4 Liquid refrigerant pipe joint Refrigerant pipe flared Ø 3 8 Gas refrigerant pipe joint Refrigerant pipe flared Ø 5 8 1 20 in 500 mm or more when front and sides of the unit are clear 14 in 350 mm or more 4 in 100 mm or more REQUIRED SPACE Clear 1 4 in 100 mm or more 20 in 500 mm or more 2 2 When any 2 sides of left right and rear of the unit are clear OBH747C ...

Page 12: ...12 5 WIRING DIAGRAM MUZ HM09NA U8 MUZ HM09NA2 U8 MUZ HM12NA U8 MUZ HM12NA2 U8 MUZ HM09NA U1 MUZ HM09NA2 U1 MUZ HM12NA U1 MUZ HM12NA2 U1 OBH747C ...

Page 13: ...13 MUZ HM15NA U1 MUZ HM15NA2 U1 MUZ HM18NA U1 MUZ HM18NA2 U1 OBH747C ...

Page 14: ...14 MUZ HM24NA U1 MUZ HM24NA2 U1 OBH747C ...

Page 15: ... 0 240 Outdoor heat exchanger temperature thermistor RT68 Service port Service port Muffler Unit Inch mm Flared connection Discharge temperature thermistor RT62 Flared connection Stop valve with strainer Stop valve with service port Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Refrigerant pipe ø3 8 ø9 52 with heat insulator Refrigerant pipe ø1 4 ø6 35 with heat in...

Page 16: ...h heat insulator Stop valve with service port Muffler MUZ HM15NA MUZ HM15NA2 MUZ HM18NA MUZ HM18NA2 MUZ HM12NA U8 MUZ HM12NA2 U8 Outdoor heat exchanger Flared connection Defrost thermistor RT61 Discharge temperature thermistor RT62 Flared connection Stop valve with strainer Stop valve with service port Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Refrigerant pipe ...

Page 17: ... 7 8 ø4 0 ø2 4 200 Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Refrigerant pipe ø5 8 ø15 88 with heat insulator Refrigerant pipe ø3 8 ø9 52 with heat insulator LEV R V coil heating ON cooling OFF Muffler with 100 mesh strainer Strainer 100 Outdoor heat exchanger temperature thermistor RT68 Strainer 100 Muffler Capillary tube O D 0 118 I D 0 079 7 7 8 ø3 0 ø2 0 20...

Page 18: ... requires additional refrigerant charge according to the calculation Model Outdoor unit precharged Refrigerant piping length one way ft 25 30 40 50 60 65 MUZ HM09NA MUZ HM09NA2 MUZ HM12NA U1 MUZ HM12NA2 U1 1 lb 12 oz 0 1 08 3 24 5 40 7 56 8 64 MUZ HM12NA U8 MUZ HM12NA2 U8 MUZ HM15NA MUZ HM15NA2 2 lb 9 oz MUZ HM18NA MUZ HM18NA2 2 lb 10 oz Calculation X oz 1 08 5 oz ft Refrigerant piping length ft 2...

Page 19: ... 10 9 10 0 1 24 MUZ HM18NA MUZ HM18NA2 71 21 1 15 3 1 46 19 7 14 3 1 60 18 5 13 4 1 72 17 2 12 5 1 81 15 8 11 5 1 89 67 20 0 17 2 1 38 18 6 16 0 1 52 17 2 14 8 1 64 16 0 13 8 1 74 14 7 12 6 1 82 63 18 7 18 6 1 31 17 4 17 3 1 45 16 2 16 1 1 57 14 7 14 6 1 67 13 4 13 3 1 74 MUZ HM24NA MUZ HM24NA2 71 27 6 20 9 2 34 25 8 19 5 2 56 24 2 18 3 2 76 22 5 17 0 2 91 20 7 15 7 3 02 67 26 1 23 2 2 21 24 3 21 ...

Page 20: ... 1 1 39 15 6 1 55 17 6 1 63 18 1 1 65 20 5 1 72 70 8 6 0 90 11 1 1 14 13 5 1 36 15 9 1 51 18 0 1 59 18 5 1 62 21 0 1 69 65 9 0 0 86 11 3 1 10 14 1 1 31 16 5 1 47 18 5 1 55 19 1 1 57 21 4 1 65 MUZ HM24NA MUZ HM24NA2 75 11 4 1 48 15 1 1 86 18 9 2 19 22 5 2 44 25 4 2 56 26 1 2 60 29 6 2 70 70 12 4 1 41 16 0 1 80 19 5 2 14 23 0 2 38 26 0 2 50 26 8 2 55 30 3 2 65 65 13 0 1 35 16 4 1 73 20 4 2 06 23 8 2...

Page 21: ...sumption kW MUZ HM09NA MUZ HM09NA2 MUZ HM12NA MUZ HM12NA2 MUZ HM24NA MUZ HM24NA2 MUZ HM18NA MUZ HM18NA2 71 67 63 65 75 85 95 105 115 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2 Indoor intake air WB temperature F SHF at rating condition 0 89 702 CFM Airflow Outdoor intake air DB temperature F Total power consumption kW 71 67 63 65 75 85 95 105 115 0 7 0 8 0 9 1 0 1 1 1 2 1 3 1 4 1 5 Indoor intake air WB temper...

Page 22: ...wer consumption kW MUZ HM09NA MUZ HM09NA2 MUZ HM12NA MUZ HM12NA2 0 10 20 30 40 50 60 70 0 3 0 5 0 7 0 9 1 1 Indoor intake air DB temperature F 406 CFM Airflow Outdoor intake air WB temperature F Total power consumption kW 75 70 65 75 70 65 0 10 20 30 40 50 60 70 0 4 0 5 0 6 0 7 0 8 0 9 1 0 1 1 1 2 Indoor intake air DB temperature F 406 CFM Airflow Outdoor intake air WB temperature F Total power co...

Page 23: ... U8 MUZ HM12NA2 U8 PSIG 6870 75 80 85 90 95 100 105 F 260 300 340 380 420 PSIG 6870 75 80 85 90 95 100 105 F 110 130 150 170 190 Condensing pressure 86 80 75 70 Suction pressure Indoor DB temperature F Outdoor ambient temperature 86 80 75 70 Indoor DB temperature F Outdoor ambient temperature MUZ HM12NA U1 MUZ HM12NA2 U1 70 75 80 85 90 95 100 105 100 120 140 160 180 PSIG PSIG 70 75 80 85 90 95 100...

Page 24: ...temperature 86 80 75 70 86 80 75 70 65 70 75 80 85 90 95 100 105 250 300 350 400 450 500 550 F F 65 70 75 80 85 90 95 100 105 80 100 120 140 160 180 200 PSIG Condensing pressure Suction pressure Outdoor ambient temperature Indoor DB temperature F PSIG Indoor DB temperature F Outdoor ambient temperature 86 80 75 70 86 80 75 70 65 70 75 80 85 90 95 100 105 200 250 300 350 400 450 500 F F 65 70 75 80...

Page 25: ... 45 55 65 75 F 5 15 25 35 45 55 65 75 F 60 85 110 135 160 185 210 260 300 340 380 420 460 Indoor DB temperature F Condensing pressure Outdoor ambient temperature PSIG PSIG 75 70 65 58Hz Indoor DB temperature F Suction pressure Outdoor ambient temperature 75 70 65 58Hz MUZ HM15NA MUZ HM15NA2 75 70 65 75 70 65 PSIG Condensing pressure Outdoor ambient temperature F F PSIG Suction pressure Outdoor amb...

Page 26: ...door DB temperature F 5 15 25 35 45 55 65 75 50 75 100 125 150 175 200 Indoor DB tem perature F 81Hz 75 70 65 75 70 65 PSIG Condensing pressure Outdoor ambient temperature F F PSIG Suction pressure Outdoor ambient temperature 5 15 25 35 45 55 65 75 250 300 350 400 450 500 58Hz Indoor DB temperature F 5 15 25 35 45 55 65 75 50 75 100 125 150 175 200 Indoor DB tem perature F 58Hz MUZ HM18NA MUZ HM18...

Page 27: ...current A 3 64 3 29 4 25 3 85 3 32 3 00 3 66 3 31 Fan motor current A 0 27 0 24 0 30 0 27 0 27 0 24 0 30 0 27 Refrigerant circuit Condensing pressure PSIG 384 331 389 331 Suction pressure PSIG 152 102 151 103 Discharge temperature F 151 155 154 152 Condensing temperature F 113 101 115 103 Suction temperature F 58 41 59 39 Comp shell bottom temperature F 146 149 151 149 Ref pipe length ft 25 Refrig...

Page 28: ...ent A 5 61 5 08 4 56 4 13 4 39 3 97 5 41 4 89 Fan motor current A 0 27 0 24 0 30 0 27 0 34 0 31 0 31 0 28 Refrigerant circuit Condensing pressure PSIG 429 347 389 397 Suction pressure PSIG 135 99 133 104 Discharge temperature F 180 165 163 162 Condensing temperature F 120 104 115 116 Suction temperature F 60 41 56 35 Comp shell bottom temperature F 174 157 158 158 Ref pipe length ft 25 Refrigerant...

Page 29: ... 6 43 11 11 10 05 10 56 9 55 Fan motor current A 0 41 0 37 0 40 0 36 0 41 0 37 0 40 0 36 1 05 0 95 1 05 0 95 Refrigerant circuit Condensing pressure PSIG 396 427 423 361 404 403 Suction pressure PSIG 138 98 144 99 127 94 Discharge temperature F 168 178 165 161 174 194 Condensing temperature F 115 120 120 108 116 116 Suction temperature F 61 31 54 35 54 44 Comp shell bottom temperature F 152 158 14...

Page 30: ...2NA U8 MUZ HM12NA2 U8 0 50 100 Hz 0 5 1 0 1 5 0 50 100 Hz 0 5 1 0 1 5 0 50 100 150 Hz 0 5 1 0 1 5 0 50 100 150 Hz 0 5 1 0 1 5 2 0 Capacity correction factors Correction of Cooling capacity The operational frequency of compressor Correction of Cooling total input The operational frequency of compressor Correction of Heating total input The operational frequency of compressor Correction of Heating c...

Page 31: ...he operational frequency of compressor Correction of Heating capacity The operational frequency of compressor Hz Hz Hz Hz 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 50 100 150 0 5 1 0 1 5 2 0 0 50 100 150 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 25 50 75 100 0 5 1 0 1 5 2 0 0 50 100 150 0 5 1 0 1 5 2 0 0 50 100 150 0 5 1 0 1 5 2 0 MUZ HM15NA MUZ HM15NA2 MUZ HM18NA MUZ ...

Page 32: ...ssor 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 Cooling Low ambient tempera ture operation Heating Defrosting Heater Outdoor heat ...

Page 33: ...essor at low outside tempera ture The pre heat control prevents this interference The pre heat control turns ON when the discharge temperature ther mistor is 68 F 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 JK wire of the inverter P C board OFF To deactivate the pre heat control solder J...

Page 34: ... careful of the residual voltage of smoothing 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 3 Troubleshooting procedure 1 Check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to ind...

Page 35: ...ore blinking does the upper lamp of the OPERATION INDICATOR lamp 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 blink...

Page 36: ...ng pattern and identify the abnormal point by referring to the table of outdoor unit failure mode recall function 10 2 3 Make sure to check at least 2 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 Press RESET button of the remote controller Repair the failu...

Page 37: ...mpressor 5 time flash 2 5 seconds OFF Discharge temperature Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 212 F 100 C or less 3 minutes later Check the refrigerant circuit and the refrigerant amount Refer to 10 5 Check of LEV 6 time flash 2 5 seconds OFF High pressure Temperature of indoor coil ...

Page 38: ...gent power module IPM power module IPM 1 The compressor winding shorts circuit Reconnect compressor connector Refer to 10 5 How to check inverter compressor 14 time flash 2 5 seconds OFF Stop valve Closed valve 14 time flash 2 5 seconds OFF Closed valve is detected by compressor current Check the stop valve 4 way valve Pipe temperature 16 time flash 2 5 seconds OFF The 4 way valve does not work pr...

Page 39: ...p valve Compressor synchronous abnormality Compressor start up failure protection 12 time flash 2 5 seconds OFF Waveform of compressor current is distorted Reconnect compressor connector Refer to 10 5 How to check inverter compressor 5 time flash 2 5 seconds OFF Discharge temperature Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if disc...

Page 40: ... Each phase current 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 Rep...

Page 41: ...tor of compressor Refer to 10 5 How to check inverter compressor Check stop valve 9 3 time flash 2 5 seconds OFF Discharge tem perature overheat protection Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 212 F 100 C or less 3 minutes later Check refrigerant circuit and refrig erant amount Refer to...

Page 42: ...h 2 5 seconds OFF Low discharge tem perature protection Temperature of discharge temperature thermistor has been 122 F 50 C or less for 20 minutes Refer to 10 5 Check of LEV Check refrigerant circuit and refrig erant amount 21 8 time flash 2 5 seconds OFF PAM protection PAM Pulse Ampli tude Modulation The overcurrent flows into IGBT Insulated Gate Bipolar tran sistor TR821 MUZ HM09 12NA 2 U8 PFC P...

Page 43: ...verter P C board for the chart of thermistor Compressor Measure the resistance between terminals using a tester Temperature 14 104 F 10 40 C Normal Ω HM09 12 U1 HM09 U8 HM12 U8 HM15 18 24 U V U W V W 1 26 1 72 1 36 1 93 1 52 2 17 0 82 1 11 W U V WHT RED BLK Outdoor fan motor Measure the resistance between lead wires using a tester Temperature 14 104 F 10 40 C Color of lead wire Normal Ω HM09 12 15...

Page 44: ...eck of open phase C Check of compressor With the connector between the compressor and the power module IPM MUZ HM09 12NA 2 U8 IC700 MUZ HM09 12NA 2 U1 MUZ HM15 18 24NA 2 disconnected activate the inverter and check if the inverter is normal by meas uring the voltage balance between the terminals Output voltage is 50 130 V The voltage may differ according to the tester Operation method Start coolin...

Page 45: ... a drier for about 20 minutes Do not recover refrigerant gas while heating Heating part Connect the compressor and activate the inverter Then measure the time until the inverter stops due to overcurrent Operation method Start heating or cooling operation by pressing EMERGENCY OPERATION switch on the indoor unit TEST RUN OPERATION Refer to 7 6 Measurement Measure the time from the start of compress...

Page 46: ...k if the coil is defective Refer to 10 4 Check if there is 208 230 VAC at L1 L2 In case CN721 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 CN721 is connected Is there 208 230 VAC between CN721 and on the inverter P C board 3 minutes after the power supply is turned ON No Yes Replace ...

Page 47: ...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 VDC 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 VDC No No Yes Check the connection between the connector CN931 and CN932 Disconnect the connectors CN931 and CN932 fr...

Page 48: ...o 10 6 1 No Replace the inverter P C board Is there DC voltage 260 325 VDC MUZ HM09 12NA 2 U8 260 370 VDC MUZ HM09 12NA 2 U1 MUZ HM15 18 24NA 2 between DB61 and DB61 on the inverter P C board Refer to 10 6 1 No Check the electric parts in main circuit Yes Yes No Disconnect the connector between the compressor and the power module IPM MUZ HM09 12NA 2 U8 IC700 MUZ HM09 12NA 2 U1 MUZ HM15 18 24NA 2 T...

Page 49: ... voltage 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 10 4 Do you hear the expansion valve click click Do you feel the expansion valve vibrate when touching it Turn ON the power su...

Page 50: ...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 flash 10 times Replace the inverter P C board Check the corresponding parts following LED indication Refer to 10 3 Yes No Yes 10 time flash No L Check of inverter P C board OBH747C ...

Page 51: ...he LED on the inverter P C board repeat 3 6 second OFF and 0 8 sec ond ON quick blinking 3 Yes No Lighted or not lighted Replace the inverter P C board 2 2 Be careful of the residual voltage of smoothing capacitor Is there amplitude of 10 to 20 VDC between the indoor terminal block S2 and S3 Confirmation of serial signal Yes Check the wiring If there are any error of the indoor outdoor connecting ...

Page 52: ... confirm the wiring is correct before the opera tion starts Turn ON the power supply Does the LED on the inverter P C board repeat 3 6 second OFF and 0 8 sec ond ON quick blinking 3 Yes No Lighted or not lighted Replace the inverter P C board 2 2 Be careful of the residual voltage of smoothing capacitor Turn OFF the power supply Remove the bridge between outdoor terminal block S2 and S3 Yes 3 Be s...

Page 53: ...zards N Check of defrost heater Check the following points before checking electric continuity 1 Does the resistance of ambient temperature thermistor have the characteristics Refer to 10 6 1 2 Is the resistance of defrost heater normal Refer to 10 4 3 Does the heater protector remain conducted not open 4 Are both ambient temperature thermistor and circuit of defrost heater securely connected to c...

Page 54: ...ondition 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 outdoor unit of the a...

Page 55: ...setting JS Signal of outdoor fan motor CN931 Outdoor heat exchanger temperature thermistor RT68 CN644 Jumper wire for pre heat control setting JK Fuse F801 T3 15AL250V Back side of unit LEV connector CN724 Output to drive outdoor fan motor CN932 LED 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat exchanger...

Page 56: ...2NA U8 MUZ HM09NA2 U8 MUZ HM12NA2 U8 Back side of unit Fin temperature thermistor RT64 CN642 Ambient temperature thermistor RT65 CN643 Discharge temperature thermistor RT62 CN641 Defrost thermistor RT61 CN641 LEV connector CN724 Bus bar voltage DB61 260 325 VDC Front side of unit 208 230 VAC Smoothing capacitor C62 Output to drive compressor LDU LDV LDW Fuse F701 T3 15AL250V Smoothing capacitor C6...

Page 57: ... 230 VAC Outdoor heat exchanger temperature thermistor RT68 CN644 Jumper wire for pre heat control setting JK Fuse F801 T3 15AL250V Back side of unit LEV connector CN724 Output to drive outdoor fan motor CN932 LED 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat exchanger temperature thermistor RT68 32 50 6...

Page 58: ... temperature thermistor RT68 CN644 Jumper wire for pre heat control setting JK Heater connector CN722 Optional parts Fuse F801 T3 15AL250V Back side of unit LEV connector CN724 Output to drive outdoor fan motor CN932 LED 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F Defrost thermistor RT61 Ambient temperature thermistor RT65 Outdoor heat exchanger temperature thermistor RT68 ...

Page 59: ... Photo 1 Photo 3 59 DISASSEMBLY INSTRUCTIONS 11 1 Slide the sleeve and check if there is a locking 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 Terminal with locking mechanism Detaching points The terminal which has the lock...

Page 60: ... panel 6 Remove the inverter assembly 7 Remove the screw of the ground wire and screw of the ter minal block support 8 Remove the heat sink support from the P C board support 9 Remove the screw of the inverter P C board and remove the inverter P C board from the P C board support Photo 6 3 Removing R V coil 1 Remove the cabinet and panels Refer to 1 2 Disconnect the following connectors Inverter P...

Page 61: ...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 Photo 8 Photo 9 61 D...

Page 62: ...rter assembly Refer to 2 3 Remove the screws fixing the reactor 4 Remove the reactor 5 Remove the soundproof felt 6 Recover gas from the refrigerant circuit NOTE Recover gas from the pipes until the pressure gauge shows 0 PSIG 7 Detach the brazed part of the suction and the discharge pipe connected with compressor 8 Remove the nuts fixing the compressor 9 Remove the compressor 10 Detach the brazed...

Page 63: ...nduit plate 9 Remove the top panel 10 Remove the valve cover 11 Disconnect the power supply and indoor outdoor connect ing wire 12 Remove the screws of the cabinet 13 Remove the cabinet 14 Remove the screws of the back panel 15 Remove the back panel Photo 3 Photo 4 Photo 1 Photo 2 63 Screws of the cabinet Screws of the top panel Screws of the top panel Screw of the back panel Screws of the cabinet...

Page 64: ...he inverter assembly 7 Remove the screw of the ground wire screw of the P C board cover and screws of the terminal block support 8 Remove the heat sink support from the P C board support 9 Remove the screw of the inverter P C board and the inverter P C board from the P C board support Photo 5 Photo 6 3 Removing R V coil 1 Remove the cabinet and panels Refer to 1 2 Disconnect the following connecto...

Page 65: ...nel Refer to 1 2 Disconnect the following connectors Inverter P C board CN931 and 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 NOTE The propeller fan nut is a reverse thread 6 Removing the compressor and 4 way valve 1 Remove the top panel cabinet and service panel Refer to 1 2 Remove the back panel Refer t...

Page 66: ...REVISED EDITION C Issued Mar 2016 No OBH747 REVISED EDITION B Issued Feb 2016 No OBH747 REVISED EDITION A Published Dec 2015 No OBH747 Made in Japan HEAD OFFICE TOKYO BUILDING 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Specifications are subject to change without notice ...

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