Mitsubishi Heavy Industries SCM71ZM-S1 Technical Manual page 265

Error code
E20
Remote control:
1. Applicable model
FDTC and FDUM series only
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-50min
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-time flash
Indoor
–
Outdoor Stays OFF
5. Troubleshooting
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 ➀-➃ of
fan motor connector
CNM?
YES
Power source reset
Is it normalized?
-1
]
Indoor fan motor rotation
Content
speed anomaly
（ FDTC, FDE and FDUM series ）
Diagnosis
YES
NO
Note (1) ➃ for GND
（1）
NO
Is the fuse F202
(FDE, FDUM:F3) blown?
YES
NO
YES
264
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'17 • SCM-T-225
Countermeasure
Remove foreign material.
Replace the fan motor.
NO 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