Mitsubishi Heavy Industries FDT90VNPWVH Service Manual page 93

Error code
E20
Remote control:
Note(1) Value in ( ) is for the FDU, 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 -50
(FDU:-500) min -1 ] 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 unit power
PCB
• Foreign material at rotational
area of fan propeller
• Defective fan motor
• Dust on indoor unit control
PCB
• Blown fuse
• External noise, surge
Note:
LED Green Red
Keeps flashing 1(2)-time flash
Indoor
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
（1）
Is DC280V
detected between - of
fan motor connector
CNM?
YES
Power source reset
Is it normalized?
92
-
Content
Indoor fan motor rotation
speed anomaly
YES
NO
Note (1) for GND
NO
Is the fuse F1, 2 or F3, 4
NO
blown?
YES
NO
YES
-
'19 • PAC-SM-334
Countermeasure
Remove foreign material.
Replace the fan motor.
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 unit control PCB.)
Malfunction by temporary
noise