Panasonic CS-A12HKD, Service Manual

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13 Protection Control
13.1. Restart Control (Time Delay Safety Control)
• When the thermo-off temperature (temperature which compressor stops to operate) is reached during:-
- Cooling/Heating operation - the compressor stops for 3 minutes (minimum) before resume operation.
- Soft Dry operation - the compressor stops for 6 minutes (minimum) before resume operation.
• If the operation is stopped by the remote control, the compressor will not turn on within 3 minutes from the moment operation
stop, although the unit is turn on again within the period.
• This phenomenon is to balance the pressure inside the refrigerant cycle.
13.2. 7 Minutes Time Save Control
• The compressor will start automatically if it has stopped for 7 minutes and the intake air temperature falls between the
compressor ON temperature and compressor OFF temperature during the period.
• This phenomenon is to reduce the built up humidity inside a room.
13.3. 60 Seconds Forced Operation
• Once the air conditioner is turned on, the compressor will not stop within 60 seconds in a normal operation although the intake air
temperature has reached the thermo-off temperature. However, force stop by pressing the OFF/ON operation button at the
remote control is permitted.
• The reason for the compressor to force operate at minimum 60 seconds is to allow the refrigerant oil run in a full cycle and return
back to the outdoor unit.
13.4. Starting current Control
• When the compressor, outdoor fan motor and indoor fan motor are simultaneously started, the indoor fan motor will start to
operate at 1.6 second later.
• The reason of the difference is to reduce the starting current flow.
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.
• 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.