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85

• During startup and operation of cooling and heating, when Power Factor Correction (PFC) protection circuitry at the outdoor unit

main PCB senses abnormal high DC voltage level.

• DC voltage peak due to power supply surge.
• DC voltage peak due to compressor windings not uniform.
• Faulty outdoor PCB.

86

• During cooling, compressor frequency = Fcmax.
• During heating, compressor frequency > Fhrated.
• During cooling and heating operation, running current: 0.65A < I < 1.65A.
• During cooling, indoor intake - indoor pipe < 4

“C

• During heating, indoor pipe - indoor intake < 5

“C

- Gas shortage detection 1: A gas shortage is detected by checking the CT-detected input current value and the compressor

running frequency. During startup and operating of cooling and heating, input current < 8.78/256 (A/Hz) x compressor
running frequency + 0.25.

- Gas shortage detection 2: A gas shortage is detected by checking the difference between indoor pipe temperature and

indoor intake air temperature during cooling and heating.

• Faulty indoor intake air or pipe temperature sensor
• 2/3 way valve closed
• Refrigerant shortage (refrigerant leakage)
• Clogged expansion valve or strainer
• Faulty outdoor unit
• Poor compression of compressor

87

A compressor rotation failure is detected by checking the compressor running condition through the position detection circuit.

• Compressor terminal disconnect
• Faulty Outdoor PCB
• Faulty compressor

88

During operation of cooling, when outdoor unit heat exchanger high temperature data (61

“C) is detected by the outdoor pipe

temperature sensor.

• Air short circuit at indoor unit
• Dust accumulation on the indoor unit heat exchanger
• 2/3 way valve closed
• Faulty outdoor unit fan motor
• Excessive refrigerant
• Clogged expansion valve or strainer
• Faulty outdoor pipe temperature sensor
• Faulty outdoor unit PCB