Mitsubishi Electric MXZ-2C30VA Service Manual page 105

• When thermistor is abnormal.
Check of outdoor thermistors
Disconnect the connector in the following table and measure
the resistance of the thermistor to check whether the thermistor
is normal or not. (Refer to 11-7.)
Normal
Reconnect the connector in the following table and
disconnect the lead wire leading to the compressor.
3 minutes after turning ON the power supply,
start EMERGENCY OPERATION.
Does the unit operate 10 minutes or more without
showing thermistor abnormality?
Yes
Normal
MXZ-2C30/2C40/2C52VA
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Fin temperature
Ambient temperature
MXZ-3C54/3C68/4C71/4C80/5C100VA MXZ-4C80/5C100VA2
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Ambient temperature
Fin temperature
MXZ-6C120VA
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Ambient temperature
MXZ-6C122VA
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Ambient temperature
OBH584G
Abnormal
Replace the inverter P.C. board, electronic
No
control P.C. board, control P.C. board,
outdoor control P.C. board, or the power
board.
Symbol Connector, Pin No.
RT61 Between CN661 pin1 and pin2
Between CN661 pin3 and pin4
RT62
RT68 Between CN661 pin5 and pin6
RT64 Between CN662 pin1 and pin2
RT65 Between CN663 pin1 and pin2
Symbol Connector, Pin No.
RT61 Between CN661 pin1 and pin2
Between CN661 pin3 and pin4
RT62
RT68 Between CN661 pin7 and pin8
Between CN663 pin1 and pin2
RT65
RT64 Between CN3 pin1 and pin2
Symbol Connector, Pin No.
RT61 Between CN661 pin1 and pin2
Between CN661 pin3 and pin4
RT62
RT68 Between CN661 pin5 and pin6
RT65 Between CN663 pin1 and pin2
Symbol Connector, Pin No.
Between CN661 pin1 and pin2
RT61
RT62 Between CN661 pin3 and pin4
Between CN661 pin5 and pin6
RT68
RT65 Between CN663 pin1 and pin2
105
Replace the thermistor except RT64.
In case that RT64 is abnormal,
replace the inverter P.C. board or
power board since RT64 is combined
with the board.
Board
Inverter P.C. board
Board
Electronic control P.C. board
Power board
Board
Control P.C. board
Board
Outdoor control P.C. board