Protection Control For Heating Operation - Panasonic WH-ADC0309H3E Service Manual

14.2

Protection Control for Heating Operation

14.2.1 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.
14.2.2 Deice Operation
When outdoor pipe temperature and outdoor air temperature is low, deice operation start where outdoor fan motor
stop.

Deice judging condition
Outdoor Unit Deice Control
10
5
0
-5
-10
-15
-20
-25
-30
-30
Deice operation time diagram
a. Deice mode 1 control:
Compressor
Four way valve
ID pump
OD fan
Expansion valve
-20 -10
Outdoor Temperature (°C)
Free
1 2
ON
ON
Free
Free
When Heating Time > 35 minutes
and Pipe Temperature below this
line for continuous 3 minutes
0 10
3 5
4
OFF
ON
OFF
max 9 minutes 30 seconds
deice 1
131
Deice start depends:
1. Outdoor air sensor temp.
2. Outdoor pipe sensor temp.
3. Heating accumulation time
20 30
8
6 7
Free
9
ON
ON
Free