Mitsubishi Electric MXZ-2D33VA-E1 Service Manual page 82

• The thermistor is abnormal.
Check of outdoor thermistors
Disconnect the connector in the following table.
Is the resistance of the thermistor normal? (Refer to 11-5.)
Yes
Reconnect the connector and disconnect the lead wire
leading to the compressor.
3 minutes after turning ON the breaker, start
EMERGENCY OPERATION.
Does the unit operate 10 minutes or more without
showing thermistor abnormality?
Yes
Normal
MXZ-2D30/2D40/2D53VA/2D53VAH
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
MXZ-3D54/3D68/4D72VA
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
MXZ-4D83/5D102VA
Thermistor
Defrost
Discharge temperature
Fin temperature
Ambient temperature
Outdoor heat exchanger temperature
OBH626B
No
Replace the inverter P.C. board, outdoor
No
control P.C. board or the outdoor power
P.C. board.
Symbol Connector, Pin No.
CN641 pin1 and pin2
RT61
RT62 CN641 pin3 and pin4
CN642 pin1 and pin2
RT64
RT65 CN643 pin1 and pin2
CN644 pin1 and pin3
RT68
Symbol Connector, Pin No.
CN661 pin1 and pin2
RT61
RT62 CN661 pin3 and pin4
CN9 pin1 and pin2
RT64
RT65 CN665 pin1 and pin2
CN661 pin7 and pin8
RT68
Symbol Connector, Pin No.
RT61 CN661 pin1 and pin2
RT62 CN661 pin3 and pin4
RT64 CN3 pin1 and pin2
RT65 CN661 pin7 and pin8
CN663 pin1 and pin2
RT68
82
Replace the thermistor except RT64.
In case that RT64 is abnormal,
replace the inverter P.C. board or the
outdoor power P.C. board since RT64
is combined with this board.
Board
Inverter P.C. board
Board
Outdoor control P.C. board
Outdoor power P.C. board
Outdoor control P.C. board
Board
Outdoor control P.C. board
Outdoor power P.C. board
Outdoor control P.C. board