Underneath Temperature Thermistor Anomaly - Mitsubishi Electric FDF71VNXVD Technical Manual

Error code
Remote controller:
E55
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 Red
Keeps flashing Stays OFF
Indoor
Keeps flashing 1 time flash
Outdoor
5. Troubleshooting
Diagnosis
underneath temperature
thermistor connector
characteristics of
underneath temperature
thermistor OK?
Temperature-resistance characteristics
15
10
5
0
192
–
Underneath temperature
Content
thermistor anomaly
(Models FDC200, 250 only)
Is the
connection of
NO
OK?
YES
Are the
NO
YES
5kΩ at 25°C
10 20 30 40 50
Temperature (°C)
–
'11 • PAC-T-160
Countermeasure
Correct connection of
underneath temperature
thermistor connector.
Defective underneath
temperature thermistor ➞
Replace.
Replace outdoor control
PCB.
(Defective underneath
temperature thermistor
input circuit)