Protection Control For Heating Operation - Panasonic WH-MHF09G3E5 Service Manual

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 fan motor stop.

Deice judging condition
Mono bloc Unit Deice Control
10
5
0
-5
-10
-15
-20
-25
-30
-30 -20

Deice mode selection condition
There are 2 deice modes, according to water inlet temperature and outdoor ambient temperature the deice
o
mode is decided.
Water inlet temperature
50°C
27°C
Judgement details:
1) When water inlet temperature is more than 50°C, unit will operate deice mode 1.
2) When water inlet temperature is less than 27°C, unit will operate deice mode 2.
3) When water inlet temperature is less than 50°C and outdoor ambient temperature is less than -10°C, unit will
operate deice mode 2.
4) When water outlet temperature sensor 2 detect temperature is less than 22°C, unit will operate deice mode 2.
When Heating Time > 35 minutes
and Pipe Temperature below this
line for continuous 3 minutes
-10 0
Outdoor Temperature (°C)
Deice mode 1
Deice mode 2
-
10°C
10 20
73
Deice start depends:
1. Outdoor air sensor temp.
2. Outdoor pipe sensor temp.
3. Heating accumulation time
30
Outdoor ambient temperature