E48 Outdoor Fan Motor Anomaly; Minutes After The Initial Detection; Presumable Cause; Yes - Mitsubishi Heavy Industries FDTC25VH1 Service Manual

Error code
Remote control: E48
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 drops to
-1
75min or lower for 30 seconds
continuously, the compressor
and the outdoor fan motor stop.
After 3-minute delay, it starts
again automatically, but if this
anomaly occurs 3 times within
60 minutes after the initial
detection.

4. Presumable cause

• Defective outdoor unit PCB
• Foreign material at rotational
area of fan propeller
• Defective fan motor
• Dust on outdoor unit PCB
• Blown F3 fuse
Note: When E48 error occurs, in almost cases F3 fuse (1A) on the outdoor unit 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 PCB ( or fuse) is replaced, another trouble 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.)
LED Green Red
Indoor Keeps flashing Stays OFF
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 DC308-336V
detected between (CNFAN 
(black)-‘ (red)) of fan motor
connector?
YES
Power source reset
Is normal state restored?
116
-
Content
Outdoor fan motor anomaly
YES
NO
NO
Is F3 (250V1A) fuse blown?
YES
NO
YES
-
'20 • SR-SM-285
Countermeasure
Remove foreign matter.
Replace fan motor.
If resistance between ➅
(Vm):red - ➃ (GND):black
is detected 1k Ω or lower, it
is faulty.
Check power source
NO
voltage.
Replace faulty fan motor
and outdoor unit PCB.
Replace fan motor (If
anomaly persists after
replacing fan motor, replace
outdoor unit PCB.)
Malfunction by temporary
noise