E51 Inverter And Fan Motor Anomaly - Mitsubishi Heavy Industries MHI FDU71VNXVF1 Technical Manual

Error code
Indoor control PCB
Remote control:
E51
Outdoor control PCB
Outdoor inverter
1. Applicable model
All models
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 ② and ③
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 ② and ③ of CNI3?
Red
Content
Stays OFF
1 time flash
Inverter and fan motor anomaly
Diagnosis
⑴ ⑵
Is DC15V
on CNI3?
Note(1) Under anomalous conditions,
the voltage becomes less than
NO
DC14V.
⑴
Is DC15V
175
- -
'12 • PAC-T-178
Countermeasure
Replace inverter PCB
YES
If not solved, replace Noise
filter PCB as well.
Replace outdoor fan motor.
YES
NO Replace outdoor control
PCB
If not solved, replace
inverter PCB as well.
② ： 15V (＋)
③ ： GND (−)
③
②