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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
Electronic control P.C. board
Power board
Board
Thermistor
Defrost
Discharge temperature
Outdoor heat exchanger temperature
Ambient temperature
Symbol
RT61
RT62
RT68
RT65
Connector, Pin No.
Between CN661 pin1 and pin2
Between CN661 pin3 and pin4
Between CN661 pin5 and pin6
Between CN663 pin1 and pin2
Outdoor control P.C. board
Board
MXZ-5B42NA
MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA
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 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
power board since RT64 is combined
with the power board.
Normal
Replace the electronic control P.C. board/outdoor
control P.C. board or the 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.
MXZ-2B20NA MXZ-3B24NA MXZ-3B30NA MXZ-4B36NA
OBH560G
Содержание MXZ-5B42NA
Страница 15: ...15 WIRING DIAGRAM 6 MXZ 2B20NA MXZ 2B20NA 1 OBH560G ...
Страница 16: ...16 MXZ 3B24NA MXZ 3B30NA MXZ 4B36NA OBH560G ...
Страница 17: ...17 MXZ 3B24NA 1 MXZ 3B30NA 1 MXZ 4B36NA 1 OBH560G ...
Страница 18: ...18 MXZ 5B42NA OBH560G ...