Suction Pipe Temperature Sensor Anomaly - Mitsubishi Heavy Industries FDT71VNXWVH Service Manual

Error code
Indoor control PCB
Remote control:
E53
Outdoor control PCB
Outdoor inverter
1. Applicable model
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
minutes.
4. Presumable cause
• Defective suction pipe
temperature sensor connection
• Defective suction pipe
temperature sensor
• Defective outdoor unit control
(or main) PCB
Note:
LED Green
Keeps flashing
Keeps flashing
Yellow LED
PCB
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
1-time flash
temperature sensor anomaly
Diagnosis
YES
Are the
5k at 25°C
0 10 20 30 40 50
Temperature (°C)
115
- -
'19 • PAC-SM-332
Suction pipe
Countermeasure
Correct connection of
NO
suction pipe temperature
sensor connector.
Defective suction
NO
pipe temperature
sensor ➞ Replace.
Defective outdoor unit
YES
control (or main)
PCB ➞ Replace.
(Defective suction pipe
temperature sensor input
circuit)