Freeze Preventive Control; Compressor Reverse Rotation Protection Control - Panasonic CS-C7HKD Service Manual

13.5. Freeze Preventive 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
and compressor turn off.
• The current fan speed will change to freeze prevention speed after 70 seconds compressor on. The fan speed will be increased
according to the indoor pipe temperature the figure below:
• Restart control (Time Delay Safety Control) will be applied in this control if the recovery time is too short.

13.6. 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.
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