Panasonic WH-UD09HE8 - Protection Control for Heating Operation

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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.
 Deice judging condition
-30
-30 -20 -10 0 10 20 30
-25
-20
-15
-10
-5
0
5
10
OD Pipe Temperature (°C)
Outdoor Unit Deice Control
line for continuous 3 minutes
and Pipe Temperature below this
When Heating Time > 35 minutes
Outdoor Temperature (°C)
3. Heating accumulation time
1. Outdoor air sensor temp.
2. Outdoor pipe sensor temp.
Deice start depends:
 Deice operation time diagram
a. Deice mode 1 control:
OD fan
ID pump
Expansion valve
Four way valve
Compressor
Free
Free
ON
OFF
OFF
ON ON
Free
5
764
98321
ON
ON
Free
Free
max 9 minutes 30 seconds
deice 1