Mitsubishi Electric MUZ-EF25VG-E1 Service Manual page 45

G Check of outdoor thermistors
Disconnect the connector of thermistor in the inverter P.C. board (see
below table), and measure the resistance of thermistor.
Is the resistance of thermistor normal?
(Refer to 12-6.1.)
Reconnect the connector of thermistor.
Turn ON the power supply and press EMERGENCY OPERATION switch.
Does the unit operate for 10 minutes or more
without showing thermistor abnormality?
OK (Cause is poor contact.)
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
OBH832C
No
Yes
No
Yes
Symbol Connector, Pin No.
RT61 Between CN641 pin1 and pin2
RT62 Between CN641 pin3 and pin4
RT64 Between CN642 pin1 and pin2
RT65 Between CN643 pin1 and pin2
RT68 Between CN644 pin1 and pin3
45
Replace the thermistor except RT64.
When RT64 is abnormal, replace the inverter P.C.
board.
Replace the inverter P.C. board.
Inverter P.C. board
Board