Siemens LMS14 User Manual page 208

SetpMin at boiler off
Prot boil startup
anticipation
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Building Technologies Division
Line no. Operating line
2263 SetpMin at boiler off
Off
On
When this function is activated, the boiler also maintains its minimum temperature when
– for certain periods of time – there are no more requests for heat from the consumers.
If the burner is running, it is shut down only if the boiler temperature exceeds its
minimum level. This means that when the requests for heat from the consumers are
satisfied, the boiler temperature is at least at its minimum level.
However, when there are no requests for heat from the consumers, the boiler is not
maintained at the minimum temperature: If the boiler temperature drops below its
minimum while the burner is Off, the burner is not put into operation.
Note!
This functionality is not available for certain special hydraulic systems. With hydraulic
configurations where the boiler pump is activated only if heating circuit 1 calls for
heat, the boiler cannot be kept hot without getting a simultaneous request for heat
from the consumer and without heat usage by the same consumer.
Off
Function is deactivated.
On
Function is activated.
Line no. Operating line
2264 Prot boil startup anticipation
When the burner is started up, the boiler temperature is expected to rise. If the rise is
not sufficient, locking signals are forwarded to the consumers, requesting them to
reduce their heat demand. This allows the boiler to reach the required temperature
level more quickly.
During protective boiler startup, the locking signal value to the consumers is calculated
based on the anticipated progression of the boiler temperature. The anticipated boiler
temperature at the current point in time + anticipation time are calculated as follows:
Actual value of boiler temperature [t
[t ] + (TKgradient * t
aktuell voraus
Eventually, the difference of anticipated boiler temperature and minimum boiler
temperature determines the value of the locking signal (0...100%).
User Manual LMS14...
6 The settings in detail
+ t ] = actual value of boiler temperature
aktuell voraus
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CC1U7471en
07.05.2014