Panasonic WH-SXF12D6E5, Service Manual

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13.1.9. Extreme Low Temperature Control
• Purpose:
- To improve the compressor reliablity during cold start and after deice when running in extreme low outdoor temperature
-20 C.
Starting condition:
1. Heating operation
2. Outdoor air tempearture < -10 C
3. Actual frequency
50Hz
4. Compressor discharge temperature < 20 C
When the above condition is fulfilled, this control is activated.
5Hz up every 30 sec. until it reaches the target frequency.
Cancelation condition:
- starting condition not fulfill.
- Cancel the extreme low temperature control when compressor discharge sensor 60 C
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 13 C or below, and discharge temperature is 13.2 C or below.
b. Resetting heater STOP condition
1. when the outdoor air temperature exceeds entry condition (15 C)
2. when the discharge temperature exceeds entry condition (20.2 C)
13.2. Protection Control For Heating Operation
13.2.1. Outdoor Air Temperature Control
The maximum current value is regulated when the outdoor air temperature rises above 14 C in order to avoid compressor
overloading.
13.2.2. Deice Operation
When outdoor pipe temperature and outdoor air temperature is low, deice operation start where outdoor fan motor stop.