Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Heating/cooling changeover 03.10.2011
27 Heating/cooling changeover
The heating/cooling changeover function block is used to change over the
operating mode (heating or cooling) in 2-pipe systems.
The preselection heating/cooling is generated on the device or received as a
heating/cooling signal from the bus.
x
Q
23
H/C changeover
The following types of changeover are available for operating mode preselection
H/C:
 Changeover with operating mode selector via operation
 Changeover with analog input (e.g. to change over by outside temperature or by
flow temperature)
 Changeover with digital input (e.g. to change over via manual switch or via
changeover thermostat in the flow)
 Changeover by date
If several changeover types are active, the operating mode is determined by the
following priority selection:
1. Operating mode selector
2. H/C changeover input
3. Heating/cooling acc to calendar
The preselected operating mode heating/cooling is provided in the heat and
refrigeration distribution zone to all other controllers within the same zone.
In a hydraulic circuit, the operating mode heating/cooling can be preselected only
via one point. If several changeover signals are sent simultaneously to the bus
within the same distribution zone, a fault message is generated.
The preselected operating mode input H/C should be activated at the precontroller
or generator where possible.
27.1 Activate function
To activate the function, Yes must be set in operating line "2-pipe heating/cooling
system".
Main menu > Commissioning > Extra configuration > Heating/cooling ch'over >
Operating line Range Factory setting
2-pipe heating/cooling system No, Yes No
Application
Recommendation
Configuration