Mitsubishi Electric FDT125VNVF Technical Manual page 420

Error code
None
Remote controller:
1. Applicable model
All models
2. Error detection method
Anomalously low temperature
or high temperature (resistance)
is detected by indoor return air
temperature sensor (Th1)
3. Condition of Error displayed
• When the temperature thermistor
detects -45°C or lower for 15
seconds continuously, the
compressor stops. After 3-minute
delay, the compressor starts again
automatically, but if this error
occurs again within 60 minutes
after the initial detection.
4. Presumable cause
• Defective room temperature
sensor connector
• Defective room temperature
sensor
• Faulty indoor control PCB
Note:
RUN light TIMER light
Indoor
2 times flash ON
display
Green LED Red LED
Outdoor
Keeps flashing Stays OFF
control PCB
5. Troubleshooting
Diagnosis
Is the
connection of room
temperature sensor
connector OK?
YES
Are the
characteristics of room
temperature sensor
OK?
Temperature-resistance characteristic
(Broken wire)
15
10
5
(Short circuit)
0
419 419
- -
Content
Room temperature
sensor anomaly
NO
NO
YES
°C
5kΩ at 25
10 20 30 40 50
Temperature (°C)
- -
'12 • PAC-T-174
Countermeasure
Correct. ➞ Connect
connector.
Defective room temperature
sensor ➞ Replace.
Defective indoor control
PCB ➞ Replace.
(Defective room
temperature sensor input
circuit)