Panasonic CS-MS9SD3H Service Manual page 52

13.5.10 H28 (Outdoor Pipe Temperature Sensor Abnormality)
Malfunction Decision Conditions

During startup and operation of cooling, the temperatures detected by the outdoor pipe temperature sensor are
used to determine sensor errors.
Malfunction Caused

Faulty connector connection.

Faulty sensor.

Faulty PCB.
Troubleshooting
When abnormality indicationstarts again
Check the connector connecti o n:
Turn off the power
●
Check the connector connecti o n
●
Is the connector connection normal?
Check the outdoor heat exchanger temperature sensor:
● Plug out connector from the outdoor unit PCB
● Measure the resistance of the outdoor heat exchanger
temperature sensor
Is the measured resistance of the outdoor heat exchanger
temperature sensor matches the value specified in its
characteristic chart?
Sensor (Thermistor)
Characteristics
70
1 Outdoor Air Sensor
2 Outdoor Heat Exchang er
60
Sensor
50
40
1
30
2
20
10
0
-10 0 10 20
Temperature (°C)
YES
YES
30 40 50
For safety reason and to prevent
component breakdown, always switch
Caution off the power before remove and
connect the component.
No
Connector poor contact
●
Correctthe connection
●
Defect in outdoor heat exchanger
●
temperaturesensor
No
Replace the outdoor heat exchanger
●
temperaturesensor
Defect in outdoor unit PCB
●
Replace the outdoor unit PCB
●
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