Panasonic CS-C12EKF, Service Manual

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11.4.5. Freeze Prevention Control
• To protect indoor heat exchanger from freezing and to prevent higher volume of refrigerant in liquid form return to compressor.
• This control will activate when the temperature of indoor heat exchanger falls below 2
°
C continuously for more than 4 minutes.
• The current fan speed will change to freeze prevention speed after 70 seconds compressor on. When indoor pipe temperature
reaches certain temperature for 5 sec. the speed will be increased as in below figure.
• Compressor will turn off when indoor temperature falls below 2
°
C for more than 4 minutes. It will restart again when indoor heat
exchanger temperature rises to 10
°
C.
• Restart control (Time Delay Safety Control) will be applied in this control.
11.4.6. Compressor Reverse Rotation Protection Control
• If the compressor is operating continuously for 5 minutes or longer and the temperature difference between intake air and indoor
heat exchanger is 2.5
°
C or less for continuous 2 minutes, compressor will stop and restart automatically.
• Time Delay Safety Control is activated before the compressor restart.
• This is to prevent compressor from rotate reversely when there is an instantaneous power failure.