Protection Control For Heating Operation - Panasonic WH-UD05JE5 Service Manual

16.2

Protection Control for Heating Operation

16.2.1 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.
16.2.2 Deice Operation
When outdoor pipe temperature and outdoor air temperature is low, deice operation start where outdoor fan motor
stop.
Normally, deice start if pipe sensor temperature fulfil deice condition. If remote controller set to AUTO force defrost
setting, unit will start force deice after heat pump operate for 3 hours without deice at below outdoor temperature 5°C

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
16.2.3 Force Defrost Operation
Force defrost can be set through remote control with two selection (Manual OR Auto).

If Manual defrost set, heat pump only run force defrost at heat mode when force defrost request from quick menu
remote control.

If Auto defrost set, heat pump automatically run force defrost operation after 3 hours heating accumulation time
without defrost when ambient below 5°C.
-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 20
3 5
4
OFF
ON
OFF
max 9 minutes 30 seconds
deice 1
170
Deice start depends:
1. Outdoor air sensor temp.
2. Outdoor pipe sensor temp.
3. Heating accumulation time
30
Free
8 9
6 7
ON
ON
Free