Check Of Outdoor Thermistor - Mitsubishi Electric MSZ-G09SV Service Manual

When OPERATION INDICATOR lamp flashes 6-time.

Check of outdoor thermistor

Z
Start
Disconnect the connector on the outdoor electronic control P. C. board (see below table),
is the resistance of thermistor normal?
Yes
Reconnect the connector (CN663 and CN664) and disconnect the lead wire from the compressor.
Turn on power supply. Press the EMERGENCY OPERATION switch.
After three minutes, check the operation of thermistor.
Does thermistor operate 10 minutes or more without indication of thermistor abnormality?
Yes
Ok
When OPERATION INDICATOR lamp flashes 10-time.
Check of outdoor fan motor
AA
Start
Reconnect the connector CN851 on outdoor electronic control P.C. board and the connector CN901 on noise filter board.
Disconnect the fan motor connector, and measure the resistance of the
fan motor winding. Is resistance of winding normal?
Yes
1. Disconnect the lead wire from the compressor. Turn ON the power supply and press the EMERGENCY
OPERATION switch.
2. After three minutes, check the voltage between No.1 and No.4 at the fan motor connector,
and between No.1 and No.5 at the fan motor connector.
Is the voltage 230V AC?
No
1. Turn OFF the power supply and disconnect the connector CN851.
2. Turn ON the power supply.
3. Measure the voltage between No.3(+) and No.7(-) at connector CN851 and between
No.3(+) and No.6(-) at connector CN851.
Is the voltage 0V?
Yes
Turn ON the power supply and press the EMERGENCY OPERATION switch.
After three minutes, is the voltage 12V DC between No.3(+) and No.6(-)
at the connector CN851?
Yes
Replace the noise filter P. C. board.
Thermistor
Discharge temperature thermistor
Defrost thermistor
Fin temperature thermistor
Yes
No
No
Replace the thermistor.
No
Replace the outdoor
electronic control P. C. board.
Symbol Connector, Pin No.
RT61 Between CN663 No.3 and No.4
RT62 Between CN663 No.1 and No.2
RT67 Between CN664 No.1 and No.2
No
No
89
Replace the fan motor.
Replace the outdoor
electronic control P. C.
board.