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Building Technologies
Boiler Sequence Controller RMK770
CE1P3132en
HVAC Products
9 Precontrol
01.03.2005
9.5
Heat demand and heat requisition
MAX
HD on/off (standard)
HD DC 0…10 V
HD HC KNX
HD DHW KNX
HD on/off DHW
HD on/off Frost protection
HD PrCtr KNX
313
2Z
19
HD
Transformer
HD PrCtr
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
Range
Factory setting
[Modulating] setpoint at 0 V
–150…50 °C
0 °C
[Modulating] setpoint at 10 V
50…500 °
100 °C
[Modulating] limit value
0…140 °C
10 °C
Following diagram shows adaptation of the signal input to the signal source.
Extra configuration