Inverter And Fan Motor Anomaly - Mitsubishi Heavy Industries FDT Series Technical Manual

Error code
Indoor control PCB
E51
Remote controller:
Outdoor control PCB
Outdoor inverter
1. Applicable model
Models FDC71-140
2. Error detection method
When power transistor anomaly
is detected for 15 minutes
continuously
3. Condition of Error displayed
Same as above
4. Presumable cause
• Outdoor fan motor anomaly
• Inverter PCB anomaly
• Outdoor control PCB anomaly
Note:
LED Green
Keeps flashing
Keeps flashing
Yellow LED
PCB
6 times flash
5. Troubleshooting
• Models FDC71-140VNX
detected between
detected after disconnecting
outdoor fan motor?
• Models FDC100-140VSX
Replace immediately the inverter PCB and the power transistor.
Note(2) How to check the voltage between
Red
Content
Stays OFF

Inverter and fan motor anomaly

1 time flash
Diagnosis
Is DC15V
and
on CNI3?
Note(1) Under anomalous conditions,
the voltage becomes less than
NO
DC14V.
Is DC15V
and of CNI3?
- 415 -
'12 • PAC-T-173
(Models FDC71-140)
Countermeasure
Replace inverter PCB
YES
If not solved, replace Noise
Replace outdoor fan motor.
YES
Replace outdoor control
NO
PCB
If not solved, replace
inverter PCB as well.