F F Check Of Outdoor Thermistors - Mitsubishi Electric MXZ-2A40VA Service Manual

• When thermistor is abnormal. (When the LED display is a table below.)

F F 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.
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 thermistor operate 10 minutes or more though the
thermistor abnormality is not displayed?
Yes
Normal
MXZ-2A40/2A52
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Fin temperature
Ambient temperature
MXZ-3A54/4A71/4A80
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Gas pipe temperature (Unit A)
Gas pipe temperature (Unit B)
Gas pipe temperature (Unit C)
Gas pipe temperature (Unit D)
Ambient temperature
Fin temperature
No
Replace the outdoor electronic
control P.C. board.
Symbol Connector, Pin No.
Between CN661 pin1 and pin2
RT61
RT62 Between CN661 pin3 and pin4
Between CN661 pin5 and pin6
RT68
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 CN662 pin1 and pin2
RT6A
RT6B Between CN662 pin3 and pin4
Between CN662 pin5 and pin6
RT6C
RT6D Between CN662 pin7 and pin8
Between CN663 pin1 and pin2
RT65
RT64 Between CN3 pin1 and pin2
68
Abnormal
Replace the thermistor.
Board
Inverter P.C. board
Board
Outdoor electronic control P.C. board
Outdoor power board