Alarm Information - Panasonic U-8ME1E81 Service Manual

11. Alarm Information

11-1. Discharge temperature
11-1-1. Discharge temperature protection
The upper limit discharge temperature is 106°C for all compressors. When the discharge temperature reaches
106°C, that compressor is stopped and restarted. If the same high discharge condition occurs 5 times, then an
alarm occurs.
After a compressor has stopped, that compressor will not operate until the temperature has dropped to or below
the start-prohibit temperature.
Discharge temperature protection list
Compressor No.
Type
Stop temp.
Start-prohibit temp.
Alarm display
11-1-2. Discharge sensor trouble detection control
-An alarm occurs if the discharge temperature remains abnormally high (above 80°C), when the system has
been stopped for 60 minutes.
*In this case, possible causes include sensor failure and compressor overheating caused by insufficient
refrigerant.
-The alarm also occurs if the sensor temperature is at or above the abnormal temperature (100°C) when 30
minutes have passed after the compressor stopped.
* In this case, it is possible that the discharge temperature from a different compressor unit is being detected, due
to an error in the installation of the discharge thermistor.
Discharge sensor failure list
Compressor No.
Type
Alarm display
11-1-3. Discharge temperature disconnection
An alarm occurs if the discharge temperature doesn't change by 2℃ or more when 10 – 30* minutes have
passed since the compressor started.
* When the ambient temperature is lower than approx –10℃, it is 30 minutes.
* When the ambient temperature is higher than approx –10℃, it is 10 minutes.
Compressor No.
Type
Alarm display
Compressor 1 Compressor 2
Inverter Constant-speed
106°C
80°C
P03
Compressor 1 Compressor 2
Inverter Constant-speed
F04
Compressor 1 Compressor 2
Inverter Constant-speed
H05
Control Functions-Outdoor Unit
Compressor 3
Constant-speed
106°C 106°C
80°C 80°C
P17 P18
Compressor 3
Constant-speed
F05 F22
Compressor 3
Constant-speed
H15
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2WAY SYSTEM
H25
1