F06, F23 Alarm; F07, F24 Alarm - Panasonic U-8ME1E81 Service Manual

4. 2WAY Alarm Codes
Check
Correction
Example
Notes
1

F06, F23 Alarm

Alarm code
Alarm meaning
2
Alarm conditions
Probable cause
Check
3
Correction
Example
Notes
4

F07, F24 Alarm

Alarm code
Alarm meaning
5
Alarm conditions
Probable cause
Check
6
Correction
Example
Notes
7
8
(3) Leakage from the discharge tube check valve
Trouble: Although the other compressor is operating and this compressor is stopped, the
discharge temperature of this compressor rises together with the temperature of the
other compressor.
(4) The ambient temperature around the outdoor unit when it is stopped is 43 °C or higher.
(5) If the cause is still unknown after checking the above, then it is possible that electrical noise is
the cause of the trouble. It is necessary to provide a line filter or carry out other noise
countermeasures.
(1) Replace the sensor.
(2) Replace the outdoor unit PCB.
(3) Carry out noise countermeasures.
(4) Repair the refrigerant tubing.
(5) Adjust the amount of refrigerant.
(6) Correct the trouble.
(1) Sensor wiring is partially cut.
This alarm does not indicate that the sensor is disconnected.
In order to prevent overheating during operation, the outdoor units in this system will not allow a
compressor to start if the discharge temperature does not decrease while the compressor is
stopped. If a sensor malfunction results in continuous detection of a high discharge temperature,
then the compressor may stop for no apparent reason. The purpose of this alarm is to facilitate
identification of the problem in this case.
F06, F23
Gas temperature sensor trouble at outdoor heat exchanger 1; Gas temperature sensor trouble at
outdoor heat exchanger 2.
(1) A/D step is 10 steps or less (short circuit).
(2) A/D step is 1014 steps or more (open circuit).
(1) Sensor malfunction (including connector)
(2) PCB malfunction
(1) Measure the sensor resistance. Check that the sensor is operating normally.
(2) Use a remote controller monitor or PC monitor to check the temperature that is recognized by
the microcomputer.
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F07, F24
Liquid temperature sensor trouble at outdoor heat exchanger 1; Liquid temperature sensor
trouble at outdoor heat exchanger 2.
(1) A/D step is 10 steps or less (short circuit).
(2) A/D step is 1014 steps or more (open circuit).
(1) Sensor malfunction (including connector)
(2) PCB malfunction
(1) Measure the sensor resistance. Check that the sensor is operating normally.
(2) Use a remote controller monitor or PC monitor to check the temperature that is recognized by
the microcomputer.
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3-14
2WAY SYSTEM
Trouble Diagnosis