Panasonic U-8ME1E81 Service Manual page 44

11. Alarm Information
11-5. 4-way valve failure
If the maximum heat exchanger temperature of the outdoor unit that operates heating mode is 20°C or higher
than the ambient temperature and this condition continues for 15 minutes, it is possible that the 4way-valve has
not changed during the heating operation.
The incidence of this situation is counted. When this counter reached 5 times, alarm occurs
1
Alarm display
11-6. Temperature Sensor Failure
When the temperature sensor fails or do not connect with PCB, "F" alarm occurs (excluding discharge
temperature sensor for compressor).
Alarm display
F06
F07
F08
F12
F14
F23
F24
H08
H27
H28
11-7. Magnet switch failure
The constant speed compressor cannot stop when the contacts of the magnet switch for compressor melt and
cannot cut out.
In this case, system compulsorily operates in cooling mode for safety.
All indoor units operate cooling mode and their fan mode is L (Low Speed).
The fan motor in the outdoor unit which magnet switch cannot cut off operates at maximum rotation speed.
* Inverter compressor and the other constant speed compressor which magnet switch is normal do not operate.
* The constant speed compressor contains an over load relay that detects abnormal temperature. Therefore,
there is no risk of danger.
4-way valve failure
L18
EXG1 Gas temperature sensor in heat exchanger 1
EXL1 Liquid temperature sensor in heat exchanger 1
TO Ambient air temperature
SCT Suction temperature
SCG Gas temperature in SC circuit
EXG2 Gas temperature sensor in heat exchanger 2
EXL2 Liquid temperature sensor in heat exchanger 2
OIL1 Oil temperature sensor 1 (Inverter compressor)
OIL2 Oil temperature sensor 2 (Constant speed compressor 1)
OIL3 Oil temperature sensor 3 (Constant speed compressor 2)
Control Functions - Outdoor Unit
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2WAY SYSTEM