E48 Outdoor Fan Motor Anomaly - Mitsubishi Heavy Industries FDT100VNAWVH Service Manual

Error code
Remote control:
E48
Indoor unit
control PCB
Outdoor unit
control PCB
1. Applicable model
All models
2. Error detection method
Detected by rotation speed of
outdoor fan motor
3. Condition of error displayed
When actual rotation speed
of outdoor fan motor (FMo1)
drops to 100min or lower
-1
for 30 minutes continuously,
the compressor and the
outdoor fan motor stop. After
3-minute delay, it starts again
automatically, but if this
anomaly occurs 5 times within
60 minutes after the initial
detection.
4. Presumable cause
• Defective outdoor unit main
PCB
• Foreign material at rotational
area of fan propeller
• Defective fan motor
• Dust on outdoor unit main PCB
• Blow fuse
• External noise, surge
Note: When E48 error occurs, in almost cases F2 fuse (4A) on the outdoor unit main PCB is blown. There are a lot of cases that fuse is blown and
E48 occurs due to defective fan motor. And even though only the outdoor unit main PCB ( or fuse) is replaced, another trouble (*1) could
occur. Therefore when fuse is blown, check whether the fan motor is OK or not.
After confirming the fan motor normal, check by power ON. (Don't power ON without confirming the fan motor normal.)
*1 The error which does not seem to relate E48 may occur like as "
communication error (E45) and etc.
LED Green
Keeps flashing
Keeps flashing
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 (CNFAN Œ
(red)- (blue)) of fan motor
connector?
YES
Is DC15V detected
between (CNFAN ⑤-③) when the
connector for FMo is removed from
outdoor unit main PCB?
YES
Power source reset
Is normal state restored?
Red
Content
Stays OFF
Outdoor fan motor anomaly
1-time flash
Diagnosis
YES
NO
Is F2 fuse blown?
", Stay OFF of LED on outdoor unit main PCB, inverter
WAIT
122
- -
'19 • PAC-SM-309
Countermeasure
Remove foreign material.
Replace fan motor.
NO
If resistance between ➀
(Vm):red - ➃ (GND):blue is
detected 1k Ω or lower, it is
faulty.
Check power source
NO
voltage.
Replace faulty fan motor
YES
and outdoor unit main PCB.
Replace outdoor unit main
NO
PCB.
Replace fan motor (If
NO
anomaly persists after
replacing fan motor, replace
outdoor unit main PCB.)
Malfunction by temporary
YES
noise