Mitsubishi Heavy Industries KXZ Series Service Manual page 110

Error code
E48
Remote control:
E48
E48
7-segment display: –
*1 1-time flash : FMo1, 2-time flash : FMo2
1. Applicable model
Outdoor unit
2. Error detection method
• If 400 min or lower of the
-1
fan rotation command and the
state of overcurent are detected
for 10 times continuously.
(CNFAN terminal:
Between 5-2 pins ...
Hi output ⇒ Overcurrent
Lo output ⇒ Normal)
• If 100 min of the actual fan
-1
rotation speed is detected for
30 seconds.
3. Condition of error displayed
Speed of 400 min -1 or less
is commanded, and state of
overcurrent is communicated.
4. Presumable cause
• Broken or disconnected wire
• Faulty fan motor
• Defective inverter PCB
• Defective control PCB
• Defective power transistor
• Defective diode module
• Defective surge suppressor
resistor
Note:
LED Green Red
Keeps flashing Stays OFF
Indoor
Keeps flashing *1
Outdoor
5. Troubleshooting
Diagnosis
From previous page
※3
Does speed command voltage of
control PCB rise gradually and stabilize
after a rise of several V?
YES
Is surge suppressor resistor
coil blown on any line?
YES
Is power transistor or diode
module short-circuited?
108
-
Content
Outdoor DC fan motor anomaly(2/2)
Power OFF
NO
NO
NO
YES
-
'14 • KX-SM-221
Countermeasure
Replace control PCB.
Replace surge suppressor resistor
on the line. (Disconnect harness
from resistor, and measure resistance
between terminals.
Replace power transistor or diode
module on poorly insulated line.
(For check method of short-circuit,
see page 58.)
Replace No. 1 or 2 fan motor.