Protection Control (Cu-3E18Lbe And Cu-4E23Lbe); Freeze Prevention Control (Cool); Dew Prevention Control (Cool); Electronic Parts Temperature Rise Protection 1 (Cool) - Panasonic CU-2E15LBE Service Manual

15 Protection Control (CU-3E18LBE and CU-4E23LBE)

15.1. Freeze Prevention control (Cool)

• When received freeze prevention signal from indoor unit, the compressor frequency changes according to indoor heat
exchanger temperature.
• When indoor unit request capability OFF due to freeze condition , immediately the capability supply to targeted indoor unit stops.

15.2. Dew Prevention control (Cool)

• When received dew prevention signal from indoor unit, the compressor frequency changes according to indoor intake
temperature and indoor heat exchanger temperature.

15.3. Electronic Parts Temperature Rise Protection 1 (Cool)

• This control prevents electronic parts temperature rise during cooling overload condition.
• Start conditions:
- Outdoor ambient temperature is at protection region as shown in figure below:
- Outdoor unit total current is above 5.5A
• Control content
- Outdoor fan speed is adjusted accordingly.
• Control stop condition
- When outdoor ambient temperature is back to normal region.
• During this control, outdoor fan speed does not reduce for Quiet operation.

15.4. Electronic Parts Temperature Rise Protection 2 (Cool)

• This control prevents electronic parts temperature rise during cooling/dry operation.
• Start conditions:
- Total current is at protection region as shown in figure below:
• Control content
- Outdoor fan speed is adjusted accordingly.
• Control stop conditions
- When total current is back to normal region.
• During this control, outdoor fan speed does not reduce for Quiet operation.
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