Panasonic WH-MXF09D3E5 Service Manual page 59

13.1.6. Low Frequency Protection Control 1
• When the compressor continuously operates at frequency lower than 25 Hz for 240 minutes, the operation frequency will change
to 24 Hz for 2 minutes.
13.1.7. Low Frequency Protection Control 2
• When all the below conditions comply, the compressor frequency will change to lower frequency.
13.1.8. High pressure sensor control
• Purpose:
- To protect the system operation.
• Detection period:
- After compressor on for 5 minutes.
• Detection conditions:
- When abnormal high voltage detection, 5V or when open circuit detection 0V for 5 seconds continuously.
• After detection:
- When abnormality is detected continue 5 seconds, unit stop operation.
- OFF/ON remote control LED will blink (H64 error occurs).
13.1.9. Outside Temperature Current Control
13.1.10. Crank case heater control
• Purpose:
- For compressor protection during low outdoor ambient operation (during heating low temperature operation).
• Control content:
a. Trigger heater START conditon
• when the outdoor air temperature is 4°C or below, and discharge temperature is 11.6°C or below.
b. Resetting heater STOP condition
1. when the outdoor air temperature exceeds entry condition (6°C)
2. when the discharge temperature exceeds entry condition (18.8°C)
Temperature, T, for:
Outlet water (°C)
Outdoor air (°C)
Indoor heat exchanger (°C)
Heating
T < 14 or T 48
T < 4 or T 24
T 0
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