Compressor Overheating Prevention Control; Low Pressure Prevention Control (Gas Leakage Detection); Low Frequency Protection Control 1; Low Frequency Protection Control 2 - Panasonic CS-XE9WKUAW Service Manual

14.1.4

Compressor Overheating Prevention Control


Instructed frequency for compressor operation will be regulated by compressor discharge temperature. The
changes of frequency are as below.

If compressor discharge temperature exceeds 224.6°F (107°C), compressor will be stopped, occurs 4 times per
20 minutes, timer LED will be blinking. ("F97" is indicated.)
14.1.5

Low Pressure Prevention Control (Gas Leakage Detection)


Control start conditions
For 5 minutes, the compressor continuously operates and outdoor total current is between 0.75A and 0.95A.
o
During Cooling and Soft Dry operations:
o
Indoor suction temperature - indoor piping temperature is below 7.2°F (4°C).
During Heating operations :
o
Indoor piping temperature - indoor suction is under 9°F (5°C).

Control contents
Compressor stops (and restart after 3 minutes).
o
If the conditions above happen 2 times within 20 minutes, the unit will:
o
 Stop operation
 Timer LED blinks and "F91" indicated.
14.1.6

Low Frequency Protection Control 1


When the compressor operate at frequency lower than 24 Hz continued for 20 minutes, the operation frequency
will be changed to 23 Hz for 2 minutes.
14.1.7

Low Frequency Protection Control 2


When all the below conditions comply, the compressor frequency will change to lower frequency.
Indoor intake air (°C)
Outdoor air (°C)
Indoor heat exchanger (°C)
Indoor intake air (°F)
Outdoor air (°F)
Indoor heat exchanger (°F)
224.6°F (107°C)
217.4°F (103°C)
(221°F (105°C))
212°F (100°C)
(203°F (95°C))
Comp. temperature
(Comp. Discharge temperature)
Temperature, T, for:
Temperature, T, for:
Compressor = OFF
197.6°F (92°C)
Compressor Frequency
Reduce
195.8°F (91°C)
Compressor Frequency
Maintain
194°F (90°C)
(185°F (85°C))
Free
Cooling/Soft Dry
T < 14 or T ≥ 30
T < 13 or T ≥ 38
T < 30
Cooling/Soft Dry
T < 57.2 or T ≥ 86.0
T < 55.4 or T ≥ 100.4
T < 86.0
79
Heating
T < 14 or T ≥ 28
T < 4 or T ≥ 24
T ≥ 0
Heating
T < 57.2 or T ≥ 82.4
T < 39.2 or T ≥ 75.2
T ≥ 32.0