Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Supply air temperature controller, demand-controlled (type P) 03.10.2011
12.4 Demand-controlled supply air temperature
control
The individual room controllers send their supply air demand signals (heat or
refrigeration) via KNX bus to the air handling unit. The air handling unit determines
and optimizes the supply air temperature setpoint from these demand signals.
Plant level:
Bus signal level:
KNX
RMU-B
RDURDG2RDG1
Max. cooling demand = 95%
Currently 60%
decrease
supply air temperature
setpoint
Cooling demand = 20% Cooling demand = 95% Cooling demand= 5%
The supply air temperature setpoint is determined within the limits of "Supply air
limit value min" and "Supply air limit value max" starting at the start value in
maintaining the limit and transition ranges linearly to the demand signals.
The start values for the supply air temperature setpoint optimization is calculated
based on the outside temperature to more quickly achieve the supply air
temperature setpoint.
 If individual room controllers are in heating mode, the supply air temperature
setpoint is increased by current demand up to max value "Supply air limit value
max".
 If individual room controllers are in cooling mode, the supply air temperature
setpoint is reduced by current demand up to minimum value "Supply air limit
value min".
The following principle applies: Cooling takes priority over heating, i.e. the heat
demand signal is ignored when occurring simultaneously to the refrigeration
demand signal.
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Controller 1 > Setpoints >
Main menu > Controller 1 >
Operating line Range Factory setting
Supply air limit value max Supply air limit value min ... 250°C 26 °C
Supply air limit value min -50°C… Supply air limit value max 15 °C
Function principle
Setpoint determination
Note
Optimization setpoint
Note
Setting values