Panasonic WH-SXC09D3E5, Service Manual

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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.
13.3. Protection Control For Cooling Operation
13.3.1. Outdoor Air Temperature Control
• The Compressor operating frequency is regulated in accordance to The outdoor air temperature as shown in The diagram below.
• This control will begin 1 minute after the compressor starts.
• Compressor frequency will adjust base on outdoor air Temperature.
13.3.2. Freeze Prevention Control 1
1. When indoor heat exchanger temperature is lower than 0°C continuously for 10 seconds, compressor will stop operating.
2. Compressor will resume its operation three minutes after the indoor heat exchanger is higher than 1°C.
3. Indoor heat exchanger freeze prevention (H99) will memory in error history.