Panasonic WH-ADC0916G9E8 WH-UX09FE8 Service Manual page 88

13.1.6 Low Frequency Protection Control 2

When all the below conditions comply, the minimum compressor frequency will change to lower frequency.
Outlet water (°C)
Outdoor air (°C)
Indoor heat exchanger (°C)
13.1.7 High Pressure Sensor Control

Purpose:
- To protect the system operation.

Detection period:
- After compressor on for 1 minute.

Detection conditions:
- When abnormal high voltage detection, 5 V or when open circuit detection 0V for 5 seconds continuously.

After detection:
- When abnormality is detected 4 times within 120 minutes, unit stop operation.
- OFF/ON control panel LED will blink (H64 error occurs).
13.1.8 Outside Temperature Current Control
13.1.9 Crank Case Heater Control

Purpose:
- For compressor protection during low outdoor ambient operation (during heating low temperature operation).

Control content:
a. Trigger heater START condition
When the outdoor air temperature is below than 5°C, and discharge temperature is 11°C or below.
o
b. Resetting heater STOP condition
When the outdoor air temperature exceeds entry condition (2°C)
1.
When the discharge temperature exceeds entry condition (5°C)
2.
Temperature, T, for:
23°C
14°C
-25°C
Heating
T < 14 or T ≥ 48
T < 4 or T ≥ 24
T ≥ 0
21°C
Max.
current
value is
regulated
12°C
-28°C
Compressor stop
Outdoor temperature
88
Cooling
T < 14 or T ≥ 30
T < 13 or T ≥ 38
T < 30