Suction Pipe Temperature Thermistor Anomaly (Tho-S); Under-Dome Temperature Thermistor Anomaly (Tho-C1); Minutes After The Initial Detection - Mitsubishi Heavy Industries FDC112KXEN6 Technical Manual

Error code
Remote controller: E53/E55*1
7-segment display: E53/E55-1
*1 E53: Error for (Tho-s), E55: Error for Tho-C1
1. Applicable model
KXE6 multi outdoor unit
2. Error detection method
Detection of anomalously low
temperature (resistance)
3. Condition of error displayed
• if -50°C is detected for 5
seconds within 2-minutes to
2-minutes 20-seconds after
the compressor ON and if this
anomaly occurs 3 times within
40 minutes after the initial
detection.
• If this anomaly occurs 1 time
within 20 seconds after power
ON.
4. Presumable cause
• Disconnection of the sensor
harness or the internal wire
of sensing part (Check the
molded part)
• Disconnection of the
thermistor connector
• Defective outdoor control
PCB
Note:
LED Green Red
Keeps flashing Stays Off
Indoor
Keeps flashing 1 time flash
Outdoor
5. Troubleshooting
Diagnosis
Save data for 30 minutes before stopping in Mente PC
Is connection
of thermistor connector
OK?
YES
Are the
characteristics of
thermistor
OK?
* Check several times the temperature-resistance characteristics of
thermistor a few times to find out any poor connection.
Suction pipe temperature thermistor (Tho-S)
Under-dome temperature thermistor (Tho-C1)
Temperature-resistance characteristics
Temperature (°C)
359
–
Content

Suction pipe temperature thermistor anomaly (Tho-S),

Under-dome temperature thermistor anomaly (Tho-C1)

NO
NO
YES
5kΩ at 25°C
–
Countermeasure
Check and save the data of
operating condition.
Check the conditions
whether it occurs
immediately after the
power on or during
operation or stopping.
Check the sensed value as
well.
Compare the temperature
on Mente PC with actual
measured value.
Insert the connector firmly
Replace thermistor.
Replace control PCB.