Heat Demand Transformers; Mixing Valve Control; General; Load Control - Siemens Synco 700 Basic Documentation

Load control

Note
Load reduction
Load increase
Settings
Main controller
Building Technologies
HVAC Products
8.5.4

Heat demand transformers

The heat demand transformers described in chapter 7 "Heat demand and heat re-
quests".
8.6

Mixing valve control

8.6.1

General

The heat output for mixing valve control can be reduced by functions of higher priority
(e.g. limitation of the return temperature) or by functions of other plants (boiler, DHW
heating) via load control.
The following mixing valve settings are valid for both 3-position and DC 0...10 V actua-
tors.
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Main controller > Mixing circuit controller
Main menu > Settings > Primary controller > Mixing circuit controller
Operating line
Actuator run time
P-band Xp
Integral action time Tn
Locking signal gain
• For more detailed information about mixing valve control and its settings, refer to
section 5.7 "Mixing valve control"
• Locking signal gain is used to preselect to what degree the primary controller shall
respond to signals received from load control
8.6.2 Load control
Load control signals from a heat source can have an impact on the primary controller:
A load reduction can be triggered by one of the following functions:
• Protective boiler startup
• Minimum limitation of the boiler return temperature
The primary controller does not respond to locking signals triggered by DHW heating.
From the consumer's point of view, a load increase can be effected in the form of pump
and / or mixing valve overrun. In that case, the load is only maintained.
8.7

Setpoint increase

Typically, a mixing valve requires a setpoint increase, enabling it to compensate for
boiler temperature variations. With system pumps, this setpoint increase is not a basic
requirement for compensating boiler temperature variations. However, in the case of
long pipes between boiler and consumers, heat losses on the way to the consumers
can occur so that a setpoint increase can be desirable in these situations also.
Main menu > Commissioning > Settings > ...
Main menu > Settings > Main controller > Main controller
Operating line
Setpoint increase
Modular Heating Controller RMH760B
8 Main controller and primary controller
Range
1...600 s
1...100 K
0...600 s
0...200 %
Range
0...50 K
Factory setting
150 s
50 K
60 s
100%
Factory setting
0 K
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CE1P3133en
05.02.2007