Panasonic CU-4E24RBU - Page 61

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15.2.6 H28 (Outdoor Heat Exchanger Temperature Sensor 1 Abnormality)
Malfunction Decision Conditions
 During startup and operation of cooling and heating, the temperatures detected by the outdoor pipe temperature
sensor are used to determine sensor errors.
Malfunction Caused
 Faulty connector connection.
 Faulty sensor.
 Faulty PCB.
Abnormality Judgment:
 Continue for 5 seconds.
Troubleshooting
Check the outdoor pipe temperature sensor:
- Plug out connector from the outdoor unit PCB
- Measure the resistance of the outdoor pipe
temperature sensor
- Defect in outdoor pipe
temperature sensor
- Replace the outdoor pipe
temperature sensor
Yes
For safety reason and to prevent component
breakdown, always switch off the power before
remove and connect the component.
Is the measured resistance of the
outdoor pipe temperature sensor
matches the value specified in its
characteristic chart?
No
Check the connector connection:
-Turnoffthepower
- Check the connector connection
- Connector poor contact
- Correct the connection
No
Is the connector
connection normal?
- Defect in outdoor unit PCB
- Replace the outdoor unit PCB
Yes
Sensor (Thermistor)
Characteristics
Outdoor Air Sensor
Outdoor Heat Exchanger
Sensor
1
2
1
2
70
60
50
40
30
20
-10
(14)
0
(32)
10
(50)
20
(68)
30
(86)
40
(104)
50
(122)
10
0
Resistance (kΩ )
Temperature °C (°F)