Compressor Overheating Prevention Control; Low Pressure Protection Control (Gas Leakage Detection); Low Frequency Protection Control 1; Low Frequency Protection Control 2 - Panasonic CS-S18NKUA Service Manual

12.5

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 233.6°F, compressor will be stopped, occurs 4 times per 20
minutes, timer LED will be blinking. "F97" is indicated.
12.6

Low Pressure Protection Control (Gas Leakage Detection)

•
Control start conditions
For 5 minutes, the compressor continously operates and outdoor total current is between 0.81A and 1.23A.
o
During Cooling and Soft Dry operation:
o
Indoor suction temperature – indoor piping temperature is below 7.2°F
•
Control contents
Compressor stops (and restart after 3 minutes).
o
If the conditions above happened 2 times within 20 minutes, the unit will:
o
Stop operation
Timer LED blinks and "F91" indicated.
12.7

Low Frequency Protection Control 1

•
When the compressor operates at frequency lower than 25Hz continued for 240 minutes, the operation frequency
will be change to 24Hz for 2 minutes.
12.8

Low Frequency Protection Control 2

•
When all below conditions comply, minimum limit of compressor frequency will be set.
Indoor intake air (°F)
Outdoor air (°F)
Indoor heat exchanger (°F)
12.9

Outdoor Air Temperature Control

•
The compressor operating frequency is regulated in accordance to the outdoor air temperature as shown in the
diagram below.
•
This control will begin 1 minute after the compressor starts.
•
Compressor frequency will adjust based on outdoor air temperature.
Temperature, T, for:
100.4°F or 77°F
Limited Frequency
Outdoor air temperature
Cooling / Soft Dry
T < 57.2 or ≥ 86
T < 55.4 or T ≥ 100.4
T < 86
Free
98.6°F or 71.6°F
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