Heat Demand And Heat Requisition; Heat Requisition Modulating - Siemens Synco700 RMK770 Documentation Handbook

Extra configuration
Building Technologies
HVAC Products
9.5

Heat demand and heat requisition

HD PrCtr
MAX
Function block "Primary controller" collects the heat demand signals from all heat con-
sumers. These are:
• Heating circuits
• DHW heating
• Other primary controllers
• Heat demand signals from individual room controllers for radiators
• Heat demand signals from individual room controllers for air heating coils
• Heat demand signals from primary air handling plant
A heat demand transformer converts the last 3 signals to a flow temperature setpoint.
In addition, 3 digital and / or 1 analog input can be configured on the controller as heat
requisition inputs.
Main menu > Commissioning > Extra configuration > Primary controller > Inputs > Heat requis
modulating
Assign terminal
Main menu > Commissioning > Extra configuration > Primary controller > Inputs > Heat requisi-
tion 2-position Assign terminal
Main menu > Commissioning > Extra configuration > Primary controller > Inputs > DHW requisi-
tion 2-pos Assign terminal
Main menu > Commissioning > Extra configuration > Primary controller > Inputs > Frost prot
requisition 2-pos
Assign input
From all requisition signals, the "Max" block (see illustration) generates the maximum
value. This maximum value is the flow temperature setpoint for the primary controller.
The setpoint is raised by the amount of the primary controller's setpoint boost and send
to a heat source or another primary controller as "Heat demand of precontrol".
9.5.1

Heat requisition modulating

A heat requisition can be preselected with a DC 0...10 V signal.
Main menu > Settings > Inputs > Heat requisition Primary controller
Operating line
[Modulating] setpoint at 0 V
[Modulating] setpoint at 10 V
[Modulating] limit value
Following diagram shows adaptation of the signal input to the signal source.
Boiler Sequence Controller RMK770
9 Precontrol
HD HC KNX
HD DHW KNX
HD PrCtr KNX
HD DC 0...10 V
HD on/off (standard)
HD on/off DHW
HD on/off Frost protection
HD
Transformer
Range
–150...50 °C
50...500 °
0...140 °C
Factory setting
0 °C
100 °C
10 °C
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CE1P3132en
01.03.2005