ABB i-bus
®
KNX
Parameters
FCC/S 1.X.X.1 | 2CDC 508 200 D0211 Rev A 101
7.4.1.1.1.1.3
—
Dependent Parameter
Type of heating/cooling system
This parameter is not visible if the
Basic-stage heating
or
Basic-stage cooling
parameters are de-
activated.
Options:
2-pipe
4-pipe
This parameter must be selected to suit the heating/cooling system in which the device is to be
used. It affects the changeover behavior of the device between heating and cooling.
•
2-pipe
: This option is to be selected if the heating and cooling devices actuated are in a 2-pipe
system. In this system, only one pipe is used to supply the device with hot and cold water. It is
therefore only ever possible to heat or cool; a changeover is necessary to change. It follows
that the device is not allowed to decide on a change between heating and cooling and the
changeover must always be made via the bus. The
Heating/Cooling changeover
parameter is
correspondingly parameterized to
Via object only
and cannot be changed.
•
4-pipe
: This option is to be selected if the devices actuated are in a 4-pipe system. In a 4-pipe
system, separate pipes are used for the hot and cold water supply. It is therefore possible to
change between heating and cooling at any time. In this situation the decision can be made
centrally, and also by the device. The
Heating/Cooling changeover
parameter is correspond-
ingly parameterized to
Automatically
.
7.4.1.1.1.1.4
—
Dependent Parameter
Heating/Cooling changeover
This parameter is not visible if the
Basic-stage heating
or
Basic-stage cooling
parameters are de-
activated.
Options:
Automatically
Via object only
Via slave and via object
The standard value for this parameter depends on the selection in the
Type of heating/cooling
system
parameter.
•
Selection of
4-pipe
:
–
Automatically
: If the
Automatically
option is selected, the changeover is only made by the
controller for the device depending on the setpoint temperature selected. Here the
Heating/
Cooling changeover
group object is hidden.
–
Via object only
: If the changeover is only allowed to be made centrally by a visualization or a
building management system, e.g. if the cooling equipment and heating equipment are not
to operate at the same time for energy-saving reasons, this parameter can also be changed
to
Via object only
. The
Heating/Cooling changeover
group object is visible.
–
Via slave and via object
: The
Heating/Cooling changeover
and
Request heating/cooling
(master)
group objects are visible. It is possible to trigger a change between heating and
cooling via the bus using these group objects. The
Request heating/cooling (master)
group
object is used for connecting to a slave analog room control unit in the context of master/
slave communication.
•
Selection of
2-pipe
:
If
2-pipe
has been selected, the standard value is set to
Via object only
and cannot be changed;
the related
Heating/Cooling changeover
group object is visible.
In a 2-pipe system, the same pipe is used for the supply of hot and cold water. Because the de-
vice cannot detect which situation is present, the changeover must always be made centrally
and sent to the device using a group object.
