Mitsubishi Electric FDT125VNVF Technical Manual page 406

Error code
Indoor control PCB
E55
Remote controller:
Outdoor control PCB
Outdoor inverter
1. Applicable model
Models FDC200, 250
2. Error detection method
When anoumalous low
temperature (resistance) is
detected by the underneath
temperature thermistor
3. Condition of Error displayed
If the temperature thermistor
detcts -50°C or lower for 5
seconds continuously within
10 minutes to 10 minutes 20
seconds after compressor ON,
the compressor stops. When
the compressor is restarted
automatically after 3-minutes
delay, if this anomaly ocuurs 3
times within 40 minute.
4. Presumable cause
• Defective underneath
temperature thermistor
connection
• Defective underneath
temperature thermistor
• Defective outdoor control
PCB
Note:
LED Green
Keeps flashing
Keeps flashing
Red LED
PCB
Keeps flashing
5. Troubleshooting
connection of
underneath temperature
thermistor connector
characteristics of
underneath temperature
thermistor OK?
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short circuit)
Red
Content
Stays OFF
1 time flash
temperature thermistor anomaly
Green LED
(Models FDC200, 250 only)
Keeps flashing
Diagnosis
Is the
OK?
YES
Are the
YES
5kΩ at 25°C
0 10 20 30 40 50
Temperature (°C)
405
- -
'12 • PAC-T-174
Underneath
Countermeasure
Correct connection of
NO
underneath temperature
thermistor connector.
NO Defective underneath
temperature thermistor ➞
Replace.
Replace outdoor control
PCB.
(Defective underneath
temperature thermistor
input circuit)