Control Of Modulating Burners - Siemens Synco 700 Series Basic Documentation

Note
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Owing to the performance of the temperature-time integral, it is not only the period of
time that is considered, but also the extent of overshoot. This means that when the
overshoot is significant, burner stage 2 is locked earlier. When the reset integral (area
"b" in the diagram) has reached the set value of the reset integral of stage 2 (point in
time t ), burner stage 2 is locked and the basic stage switched off.
reset
TBo
TBoSp+ / SDBo
1
2
TBoSp- / SDBo
1
2
BSt1
1
0
INT
max.
RlsINT
0
RlsBSt2
1
0
BSt2
1
0
BSt1 Burner stage 1
BSt2 Burner stage 2
INT Integral
Rls Release
Rst Reset
SD Switching differential
Sp Setpoint
t Time
Tbo Boiler temperature
If, with stages 1 and 2 released, both stages are locked at the same time, the basic
stage is switched off with a delay of 10 seconds. Switching off in 2 phases also reduces
the pressure shocks in the gas supply line. This prevents unnecessary lockout in the
case of large burner capacities.
7.8.4

Control of modulating burners

Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler ... > Burner modulating
Operating line
Actuator running time
P-band Xp
Integral action time Tn
Derivative action time Tv
Modulating burners operate in modulating mode only above a certain level (for normal
forced draft burners, this limit is about 30 to 40% of the rated capacity).
Boiler Sequence Controller RMK770
7 Boiler control
max.
RstINT
Range
1...600 s
1...100 K
0...600 s
0...30 s
t
t
RstINT
t
t
t
Factory setting
60 s
20 K
150 s
5 s
CE1P3132en
23.04.2009