Panasonic CS-E7NKDW, Service Manual

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14.1.4 Compressor Overheating Prevention Control
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Instructed frequency for compressor operation will be regulated by compressor discharge temperature. The
changes of frequency are as below.
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If compressor discharge temperature exceeds 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)
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Control start conditions
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For 5 minutes, the compressor continuously operates and outdoor total current is between 0.75A and 0.95A
(E7/9/12/15NK), 1.38A and 1.65A (E18NK).
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During Cooling and Soft Dry operations:
Indoor suction temperature - indoor piping temperature is below 4°C.
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During Heating operations :
Indoor piping temperature - indoor suction is under 5°C.
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Control contents
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Compressor stops (and restart after 3 minutes).
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If the conditions above happen 2 times within 20 minutes, the unit will:
ƒ Stop operation
ƒ Timer LED blinks and “F91” indicated.
14.1.6 Low Frequency Protection Control 1
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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
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When all the below conditions comply, the compressor frequency will change to lower frequency.
Temperature, T, for: Cooling/Soft Dry Heating
Indoor intake air (°C) T < 14 or T ≥ 30 T < 14 or T ≥ 28
Outdoor air (°C) T < 13 or T ≥ 38 T < 4 or T ≥ 24
Indoor heat exchanger (°C) T < 30 T ≥ 0