52
Check of outdoor thermistors
• When thermistor is abnormal.
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Ambient temperature
Fin temperature
Symbol
RT61
RT62
RT68
RT65
RT64
Connector, Pin No.
Between CN661 pin1 and pin2
Between CN661 pin3 and pin4
Between CN661 pin7 and pin8
Between CN663 pin1 and pin2
Between CN3 pin1 and pin2
Outdoor electronic control P.C. board
Outdoor power board
Board
Check of outdoor fan motor
• Fan motor does not operate or stops operating shortly after starting the operation.
Yes
Yes
Yes
No
(Fixed to either 5 V or 0 V DC)
No
No
Turn ON the power supply.
Rotate the outdoor fan motor manually and measure the voltage of
CN931.
Between (+) and (-)
Between (+) and (-)
Between (+) and (-)
Does the outdoor fan motor rotate smoothly ?
Does the voltage between each terminal become 5 V DC and 0 V DC
repeatedly ?
Replace the outdoor fan motor.
Replace the outdoor electronic control P.C. board.
Disconnect CN932 from the outdoor
electronic control P.C. board, and measure
the resistance of the outdoor fan motor.
Is the resistance of outdoor fan motor
normal? (Refer to 11-5.)
Normal
Yes
No
Abnormal
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.)
Does the unit operate 10 minutes or more without
showing thermistor abnormality ?
Replace the thermistor except RT64.
In case that RT64 is abnormal, replace the
outdoor power board since RT64 is combined
with the outdoor power board.
Normal
Replace the outdoor electronic control
P.C. board or the outdoor power board.
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.
