Indoor Fan Motor Rotation Speed Anomaly - Mitsubishi Electric FDT125VNVF Technical Manual

Error code
E20
Remote controller:
Note (1) Value in ( ) is for the FDUM series FMI2 only.
1. Applicable model
All models
2. Error detection method
Detected by rotation speed of
indoor fan motor
3. Condition of Error displayed
When the actual fan rotation
speed does not reach to the
speed of [required speed
-50rpm] after 2 minutes have
been elapsed since the fan
motor rotation speed command
was output, the unit stops by
detecting indoor fan motor
anomaly.
4. Presumable cause
• Defective indoor power (control)
PCB
• Foreign material at rotational
area of fan propeller
• Defective fan motor
• Dust on control PCB
• Blown fuse
• External noise, surge
Note:
LED Green Red
Keeps flashing 1 ( 2 ) time flash
Indoor
Keeps flashing Stays OFF
Outdoor
5. Troubleshooting
Diagnosis
Does any
foreign material
intervene in rotational area
of fan propeller?
NO
Does the fan
rotate smoothly when turned
by hand?
YES
Is DC280V
detected between - of
fan motor connector
CNM?
Is the fuse F3 (F4) or F202
YES
Power supply reset
Is it normalized?
385
-
Indoor fan motor rotation
Content
speed anomaly
YES
NO
Note (1) for GND
（1）
FDEN, FDU series
NO
FDT, FDTC, FDUM and
FDF series
NO
blown?
YES
NO
YES
-
'12 • PAC-T-174
Countermeasure
Remove foreign material.
Replace the fan motor.
Replace control PCB.
Check power voltage.
Replace faulty fan motor
and power PCB.
Replace fan motor. (If the
error persists after replacing
the fan motor, replace the
indoor control PCB.)
Malfunction by temporary
noise