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Building Technologies
Boiler Sequence Controller RMK770
CE1P3132en
HVAC Products
5 General functions, fundamentals
23.04.2009
To prevent the pumps and valves from seizing, a point in time (kick day and kick time)
can be defined at which the pumps are put into operation and the valves are driven to
their fully open and fully closed positions.
The function can be deactivated (pump / valve kick = ---).
It can also be selected whether the function shall apply to pumps only, to valves only, or
to both.
The selected setting then applies to all pumps and valves connected to the RMK770
controller. If a plant uses several RMK770, that setting must be made on every controller.
With the kick day and kick time settings, it is to be noted that these settings are also
used for automatic changeover of twin pumps (for more detailed information, refer to
section 5.8 “Pump control”).
The running time for the pumps and actuators need not be set. It is always 30 seconds.
If several pumps are used, they are kicked one after the other. After the end of a kick, the
next pump will be kicked after an interval of 30 seconds.
The valve kick does not act on the shutoff valves.
5.6
Heat demand and load control
5.6.1 Heat
demand
Heat consumers like heating circuits and DHW heating send their heat demand signals
to the heat distribution zone “Heat generation”.
An RMU… universal controller or RXB… individual room controller can also send heat
demand signals. A demand transformer converts these signals to appropriate heat
demand signals (for more detailed information, refer to chapter 8 “Heat demand and
heat requests“
).
Heat sources or primary controllers receive the heat demand signals and evaluate
them. Usually, evaluation consists of a maximum value generation of the temperatures
from the heat demand signal.
A heat source or boiler sequence (example 1) attempts to deliver the required amount
of heat. A primary controller (example 2) also tries to deliver that amount of heat; in
addition, it sends a heat demand signal to a heat source.
T
T
31
31
B
1
5
T
Heat
consumer
Heat
source
Load control
Heat demand
Heat
consumer
Notes
Examples
Example 1: Heat source
and heat consumer