The change-over command switches a change-over valve between the heating and cooling energy sources. Its states depend on the input “HVAC_Mode” and the setting of SYS-01, 4-pipe system.
In 4-pipe operation mode (4-pipe system SYS-01 = 1), the change-over valve will always be in the position “heat” – value “0”.
The change-over command position for a 2-pipe configuration (4-pipe system SYS-01 = 0) is shown in the table below.
Table 8. Change-over valve command
HVAC_Mode |
SYS-01 |
Change-over Command |
0,1 |
0 |
heat = 0 |
2 |
0 |
heat = 0 |
3 |
0 |
cool = 1 |
4 |
0 |
heat = 0 |