Figure 2-7 Control behaviour for the Heating/Cooling (change-over) controller mode when the controller is in cooling
mode.
2.1.6
H Heating/Cooling (change-over)
This controller mode is suitable for room HVAC systems that use a 2-pipe fan coil as heating and cooling
device, and where an additional heating device, typically an electrical heating battery, is used to provide
extra heating during cold seasons.
The controller is set to operate in either H Heating mode or H Cooling mode by using the
change-over function. The change-over function makes it possible to use the controller in a 2-pipe change-
over system, where warm or cold media flow in the same pipes and one valve is used to regulate both heating
and cooling distribution. See section
for information about the change-over function.
The controller operates in H Heating mode when the controller change-over state is
heating
, and in
H Cooling mode when the controller change-over state is
cooling
. See section
for information
about the controller change-over state.
The H Heating mode is typically used during cold seasons, such as winter. The H Cooling
mode is typically used during warm seasons, such as summer.
H Heating mode
The controller acts as a heating controller and regulates based on the heating setpoint and the current room
temperature.
The controller is always in heating mode and outputs two heating signals, Y1 and Y2, in sequence that are
configured on the controller outputs by using the configuration values listed in table
.
The Y1 output signal is associated with the 2-pipe fan coil and increases first to respond to the initial heating
demand. The Y2 output signal is associated with the additional heating device and responds to any further
heating demand that the 2-pipe fan coil cannot meet.
Maximum and minimum limits for the output signals can be set, see section
.
Y1: Change-over valve (cooling mode) signal
Output
Max: 100%
Cooling
setpoint
Min: 0%
Room temperature
100%
0%
Cooling demand
12
Regio
Eedo
manual, Rev. D