Change-Over Command

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