Discharge Temperature - Panasonic U-10MF1E8 Service Manual

13. Discharge Temperature

<Alarm Information>
(1) Discharge temperature protection alarm
This device sets an upper limit discharge temperature of 105°C for all compressors. When the discharge tem-
perature reaches 105°C, that compressor is stopped and restarted. If the same high discharge condition occurs
4 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
(2) Discharge sensor trouble detection control
An alarm occurs if the discharge temperature remains abnormally high when the system has been stopped for
60 minutes.
* In this case, possible causes include sensor failure and compressor overheating caused by an insufficient
level of refrigerant.
The alarm also occurs if the sensor temperature is at or above the abnormal temperature (80°C) when 20 min-
utes have passed after the compressor stopped.
* In this case, it is possible that the discharge temperature from a different outdoor unit is being detected, due to
an error in the installation of the discharge thermistor.
Discharge sensor failure list
Compressor No.
Type
Stop temp.
Compressor 1 Compressor 2
Inverter Constant-speed
105
90
P03
Compressor 1 Compressor 2
Inverter Constant-speed
F04
Compressor 3
Constant-speed
105 105
90 90
P17 P18
Compressor 3
Constant-speed
F05 F22
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3-WAY SYSTEM
Control Functions
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