Panasonic CS-E7MKDW / CU-E7MKD / CS-E9MKDW / CU-E9MKD / CS-E12MKDW / CU-E12MKD / CS-E15MKDW / CU-E15MKD / CS-E18MKDW / CU-E18MKD Service Manual ▷ View online
101
16.4.23. F90 (Power Factor Correction Protection)
Malfunction Decision Conditions
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.
main PCB senses abnormal high DC voltage level.
Malfunction Caused
• DC voltage peak due to power supply surge.
• DC voltage peak due to compressor windings not uniform.
• Faulty outdoor PCB.
• DC voltage peak due to compressor windings not uniform.
• Faulty outdoor PCB.
Troubleshooting
102
16.4.24. F91 (Refrigeration Cycle Abnormality)
Malfunction Decision Conditions
• 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
• 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
Multi Models Only
- 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.
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.
Malfunction Caused
• 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
• 2/3 way valve closed
• Refrigerant shortage (refrigerant leakage)
• Clogged expansion valve or strainer
• Faulty outdoor unit
• Poor compression of compressor
Troubleshooting
103
16.4.25. F93 (Compressor Rotation Failure)
Malfunction Decision Conditions
A compressor rotation failure is detected by checking the compressor running condition through the position detection circuit.
Malfunction Caused
• Compressor terminal disconnect
• Faulty Outdoor PCB
• Faulty compressor
• Faulty Outdoor PCB
• Faulty compressor
Troubleshooting
104
16.4.26. F95 (Cooling High Pressure Abnormality)
Malfunction Decision Conditions
During operation of cooling, when outdoor unit heat exchanger high temperature data (61
C) is detected by the outdoor pipe
temperature sensor.
Malfunction Caused
• 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
• 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
Troubleshooting
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