Panasonic CS-RE18NKE Service Manual page 66

15.5.16 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
o
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
o
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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