Alarm Information - Panasonic U-8MF2E8 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
1
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 sensor.
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°C or more when 10 – 30* minutes have passed
since the compressor started.
* When the ambient temperature is lower than approx -10°C, it is 30 minutes.
* When the ambient temperature is higher than approx -10°C, it is 10 minutes.
Compressor No.
Type
Alarm display
Compressor 1 Compressor 2
Inverter Constant speed
106°C 106°C
80°C 80°C
P03
Compressor 1 Compressor 2
Inverter Constant speed
F04
Compressor 1 Compressor 2
Inverter Constant speed
H05
1 - 40
P17
F05
H15
3WAY SYSTEM
Control Functions