Panasonic F91 Error Code: Refrigeration Cycle Abnormality and Troubleshooting Guidelines

15.4.16. 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°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.

-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

•Refrigerant shortage (refrigerant leakage)

•Poor compression performance of compressor.

•2/3 way valve closed.

•Detection error due to faulty indoor intake air or indoor pipe temperature sensors.

Troubleshooting

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