76 
14.5  Compressor Overheating Prevention Control 
  Instructed frequency for compressor operation will be regulated by compressor temperature. The changes of 
frequency are as below. 
  If compressor temperature exceeds 107°C, compressor will be stopped, occurs 4 times per 20 minutes, timer 
LED will be blinking. “F97” is indicated. 
 
Compressor=OFF
Compressor Frequency
Reduced
Compressor Frequency
Maintain
Free
Comp Tank temperature
107°C
91°C
103°C
100°C
92°C
90°C
 
14.6  Low Pressure Prevention Control (Gas Leakage Detection) 
  Control start conditions 
o  For 5 minutes, the compressor continuously operates and outdoor total current is between 0.65 A and 1.65 A. 
o  During Cooling and Soft Dry operation: 
Indoor suction temperature - indoor piping temperature is below 4°C. 
  Control contents 
o  Compressor stops (and restart after 3 minutes). 
o  If the conditions above happened 2 times within 20 minutes, the unit will: 
  Stop operation. 
  Timer LED blinks and “F91” indicated. 
14.7  Low Frequency Protection Control 1 
  When the compressor operates at frequency lower than 24 Hz continued for 240 minutes, the operation 
frequency will be changed to 23 Hz for 2 minutes. 
14.8  Low Frequency Protection Control 2 
  When all below conditions comply, the compressor frequency will changed to lower frequency. 
 
Temperature, T, for:  Cooling / Soft Dry 
Indoor intake air (°C)  T < 14 or T ≥ 30 
Outdoor air (°C)  T < 13 or T ≥ 38 
Indoor heat exchanger (°C)  T < 30