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Building Technologies
Boiler sequence controller RMK770
CE1P3132en
HVAC Products
6 Boiler sequence management
23.04.2009
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Boiler sequence manager > Demand control
Main menu > Settings > Primary controller > Demand control
Operating line
Range
Factory setting
[Curvepoint 1] outside temp
–50…50 °C
–10 °C
[Curvepoint t 1] flow temp
0…140 °C
70 °C
[Curvepoint 2] outside temp
–50…50 °C
20 °C
[Curvepoint 2] flow temp
0…140 °C
70 °C
A total of 3 types of digital input are available. They are distinguished in the way they
handle heat demand signals and in the different setting choices they offer:
•
A signal received at input ”Heating curve request 2-pos“ is handled like a heat de-
mand signal from one of the heating circuits. The setpoint is dependent on the out-
side temperature and determined via the same heating curve as demand control. For
more detailed information about demand control, refer to section 8.3 ”Heat demand
transformers“
•
A signal received at input “DHW request 2-pos“ is handled like a signal from DHW
heating. A constant setpoint can be preselected. Also, the priority of the resulting
DHW request can be selected. For more detailed information about DHW priority,
refer to subsection 5.6.2 “Load control“.
•
A signal received at input “Frost prot request 2-pos“ is handled like a heat request
resulting from risk of frost. A constant setpoint can be preselected
A heating curve request can be ignored in the summer while consideration is given to
frost protection requests, depending on the plant’s state.
Whether the input shall be active with the contact open or closed can be parameterized
for each input.
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Inputs > RMK770.X…
(or
RMZ78…
)
Operating line
Range
Factory setting
Normal position
Open / Closed
Open
Normal position “Open“ means that the input is active when the contact is closed.
6.5.3
Heat demand transformers
For a description of the heat demand transformers, refer to section 8.3 “Heat demand
transformers“
6.6
Other functions
6.6.1
Common maintained boiler return temperature
Minimum limitation of the return temperature shall ensure that, by the boiler inlet also,
the temperature does not drop below the permissible value. In most cases, this is
solved separately on each individual boiler. But it is also possible to perform this func-
tion for all boilers from a central location.
When, in
Extra configuration > Boiler sequence,
a sensor has been configured for the
maintained boiler return temperature and an output for the maintained boiler return
temperature (3-position or modulating), the common maintained boiler return tempera-
ture is ensured by a mixing valve.
The setpoint of the return temperature is to be configured on submenu
Limitations
, and
the parameters for control on submenu
Return control
.
For more detailed information about mixing valve control, refer to section 5.7 “Mixing
valve control”.
Digital inputs
With mixing valve
