Heating/Cooling Changeover - Siemens RXB Series Basic Documentation

Use
Effect of specified
mode
Note
Activate function
Configuration
For internal use only
Siemens
Building Technologies
9.2

Heating/cooling changeover

The universal RMU7x0B controllers are programmed with the new "H/C
changeover" function block, which is used for changeover of the specified
"Heating" or "Cooling" mode in 2-pipe systems.
x
H/C changeover
23
Q
The specified "Heating" or "Cooling" mode can be generated in the controller itself,
or received as a "Heating/cooling changeover signal" over the KNX bus.
The following methods of changeover can be programmed for the specified
"Heating/Cooling" mode:
Changeover via digital input, e.g. with manual switch or with a changeover
thermostat in the flow (already an option with RMU7x0).
Changeover vie analog input, e.g. based on outside air temperature or flow
temperature.
Changeover based on the calendar (date): Configured in the "H/C Changeover"
function block (calendar symbol selected).
Changeover with operating mode selector. Configured in the "H/C Changeover"
function block ("Hand" symbol selected).
The "Heating/Cooling" mode is not affected by the type of changeover.
If several types of changeover are selected, the required operating mode is
determined in the following order of priority:
1. Operating mode selector
2. H/ C changeover input
3. Heating/cooling by calendar
The required "Heating/Cooling" mode is transmitted by the "changeover controller"
to all other controllers in the heating distribution and refrigeration distribution
zones.
In a hydraulic circuit, the "Heating/Cooling" mode can be defined in one location
only. If several H/C changeover signals in the same distribution zone are
distributed over the KNX bus, a fault message is generated.
If possible, the required "Heating/Cooling" changeover command should be
activated in the primary controller or generator.
The "H/C changeover" function is activated by setting the operating line "2-pipe
system heating/cooling" to "Yes".
Main menu > Commissioning > Extra configuration > Heating/cooling ch'over
Operating line
2-pipe heating/cooling system
KNX bus communications
Appendix
Range Factory setting
No, yes. No
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CE1P3127en
2013-04-08