Description: Signal Transmission Error (between Indoor Unit and Outdoor Unit) Method of Malfunction Detection: The data received from the outdoor unit in indoor unit-outdoor unit signal transmission is checked whether it is normal. Malfunction Decision Conditions: The data sent from the outdoor unit cannot be received normally, or the content of the data is abnormal. … Read more
Description: Low-voltage Detection or Over-voltage Detection. Method of Malfunction Detection: Indoor Unit The zero-cross detection of the power supply is evaluated by the indoor unit PCB. Outdoor Unit Low-voltage detection: An abnormal voltage drop is detected by the DC voltage detection circuit. Over-voltage detection: An abnormal voltage rise is detected by the over-voltage detection circuit. … Read more
Description: Refrigerant Shortage. Method of Malfunction Detection: Refrigerant shortage detection I: Refrigerant shortage is detected by checking the input current value and the compressor running frequency. If the refrigerant is short, the input current is lower than the normal value. Refrigerant shortage detection II: Refrigerant shortage is detected by checking the discharge pipe temperature and … Read more
Description: Thermistor or Related Abnormality (Indoor Unit). Method of Malfunction Detection: The temperatures detected by the thermistors determine thermistor errors. Malfunction Decision Conditions: The thermistor input is more than 4.96 V or less than 0.04 V during compressor operation. Supposed Causes: Disconnection of connector Defective thermistor Defective indoor unit PCB Troubleshooting Procedure
Description: Freeze-up Protection Control or Heating Peak-cut Control. Method of Malfunction Detection: Freeze-up protection control During cooling operation, the freeze-up protection control (operation halt) is activated according to the temperature detected by the indoor heat exchanger thermistor. Heating peak-cut control During heating operation, the temperature detected by the indoor heat exchanger thermistor is used for … Read more