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Building Technologies
Boiler sequence controller RMK770
CE1P3132en
HVAC Products
7 Boiler control
23.04.2009
The maximum value is filtered to suppress faults. As a result, the maximum flue gas
temperature rises at the rate of maximum 1 K/s.
If a flue gas temperature limit value is parameterized, a fault status message is deliv-
ered when the limit value is crossed.
Main menu > Commissioning > Settings > …
or
Main menu
>
Settings > Boiler … > Fault settings > Flue gas temperature supervision
Operating line
Range
Factory setting
Flue gas temperature limit value
---- / 8…400 °C
---- °C
When the flue gas temperature lies 5 K below that maximum flue gas temperature, the
fault status message can be reset by acknowledging it. When resetting, the slave
pointer valve is also reset to the current value.
Main menu > Commissioning > Settings > …
or
Main menu
>
Settings > Boiler … > Fault settings > Flue gas temperature supervision
Operating line
Range
Factory setting
Impact of fault
No stop / Stop
No stop
Fault priority
Urgent / Nonurgent
Nonurgent
If a flue gas temperature limit value is monitored, it is also possible to define if crossing
of the limit value shall cause the boiler to shut down (No stop, Stop).
Main menu > Boiler … > Inputs/setpoints
Operating line
Adjustable values / remarks
Flue gas temperature
---- / 8…400 °C
Flue gas temperature maximum
---- / 8…400 °C
The current flue gas temperature and the maximum flue gas temperature are available
as diagnostic values.
7.12 Flue gas measuring mode
Flue gas measurement can be triggered via a digital input (
Inputs > Flue gas measuring
mode
) or operation.
Main menu > Boiler … > Flue gas measuring mode
Operating line
Range
Factory setting
Preselection
Off / On
Off
Flue gas meas mode contact
0 / 1
Release stage 2/modulation
Yes / No
Yes
Actual value boiler temperature
Flue gas temperature
If the function is activated with one of the boilers, all boilers in the boiler sequence are
shut down. With the relevant boiler, the boiler pump and the peripheral devices are put
into operation. The boiler is assigned a boiler temperature setpoint of 90 °C. This value
is limited by the maximum boiler temperature.
During the period of time the “Flue gas measuring mode“ function is performed, supervi-
sion of the maximum flue gas temperature does not lead to a plant stop. However, if the
maximum flue gas temperature is exceeded, a fault status message is delivered.
The function will be aborted after 30 minutes.
Supervision of the
maximum value
Supervision of the
maximum value and
boiler stop
Diagnostic values