Suction Pipe Temperature Sensor Anomaly - Mitsubishi Heavy Industries FDT100VNAWVH Service Manual

Error code
Remote control:
E53
Indoor unit
control PCB
Outdoor unit
control PCB
1. Applicable model
All models
2. Error detection method
When the suction pipe
temperature sensor detects
anomalously low temperature
3. Condition of error displayed
If the temperature sensor detects
-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-minute delay, if this anomaly
ocuurs 3 times within 40
minute.
4. Presumable cause
• Defective suction pipe
temperature sensor
connection
• Defective suction pipe
temperature sensor
• Defective outdoor unit main
PCB
Note:
LED Green
Keeps flashing
Keeps flashing
5. Troubleshooting
Is the connection
of suction pipe temperature sensor
connector OK?
characteristics of suction pipe
temperature sensor OK?
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short- circuit)
Red
Content
Stays OFF
temperature sensor anomaly
1-time flash
Diagnosis
YES
Are the
5k at 25°C
0 10 20 30 40 50
Temperature (°C)
126
- -
'19 • PAC-SM-309
Suction pipe
Countermeasure
Correct connection of
NO
suction pipe temperature
sensor connector.
Defective suction
NO
pipe temperature
sensor ➞ Replace.
Defective outdoor unit
YES
main PCB ➞ Replace.
(Defective suction pipe
temperature sensor input
circuit)