Mitsubishi Electric FDT125VNVF Technical Manual page 445

Indoor display
Error code
E48
Remote controller:
inverter 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-minutes delay, it starts
again automatically, but if this
anomaly occurs 5 times within
60 minutes after the initial
detection.
4. Presumable cause
• Defective outdoor control
PCB
• Foreign material at rotational
area of fan propeller
• Defective fan motor
• Dust on outdoor control PCB
• Blow fuse
• External noise, surge
Note: When E48 error occurs, in almost cases F2 fuse (4A) on the outdoor control 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 control 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.
RUN light
ON
Green LED
Outdoor
control PCB
Keeps flashing
Yellow LED
Outdoor
Keeps flashing
5. Troubleshooting
Does any foreign
material intervene in rotational area
of fan propeller?
fan rotate smoothly when turned
detected between (CNFAN �
(red)-� (blue)) of fan motor
Power supply reset
Is normal state restored?
TIMER light
Content
7 times flash
Outdoor fan motor anomaly
Red LED
1 time flash
Diagnosis
NO
Does the
by hand?
YES
Is DC280V
NO
connector?
Is F2 fuse blown?
YES
YES
", Stay OFF of LED on outdoor control PCB, inverter
WAIT
444
- -
'12 • PAC-T-174
Countermeasure
Remove foreign material.
YES
Replace fan motor.
NO
If resistance between ➀
(Vm):red - ➃ (GND):blue is
detected 1k Ω or lower, it is
faulty.
Check power supply
NO
voltage.
Replace faulty fan motor
YES
and control PCB.
Replace fan motor (If
NO
anomaly persists after
replacing fan motor, replace
control PCB.)
Malfunction by temporary
noise