Siemens Synco 700 Series Basic Documentation page 82

Example
Example
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Building Technologies
HVAC Products
Boiler sequence with 4 boilers and 2-stage burners as an example. Lag boilers with
great setpoint increase.
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0
0 20 40 60 80 100
Burner stage in continuous operation
Burner stage cycling
Main menu > Commissioning > Settings > ... or
Main menu > Settings > Boiler ... > Operation settings
Operating line
Setpoint increase lag boiler
A great setpoint increase (to be set separately on each boiler) allows the lead boiler to
provide control while the relevant lag boiler operates at full capacity. This way, it is
made certain that several boilers with their burner stages do not cycle simultaneously.
With a small setpoint increase, or no increase at all, the relevant lag boiler also pro-
vides control. This can be especially desirable in the case of boiler sequences with
several modulating burners.
Boiler sequence with 4 boilers and modulating burners as an example.
Lag boilers with small setpoint increase or no increase at all.
400
380
360
340
320
300
280
260
240
220
200
180
160
140
120
100
80
60
40
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0
0 20 40 60 80 100
Burner stage modulating
In the case of boilers with greatly different capacities (e.g. second boiler twice the
capacity of the first boiler), the second boiler can be put into operation after the first
boiler and the first boiler is shut down. The first boiler resumes operation only when
both stages of the second boiler are on. This ensures a better graduation of the total
boiler output.
Boiler Sequence Controller RMK770
6 Boiler sequence management
120 140 160 180 200 220 240
Heat demand or load
Range
0...50 K
120 140 160 180 200 220 240
Heat demand or load
260 280 300 320 340 360 380
Factory setting
10 K
260 280 300 320 340 360 380
CE1P3132en
23.04.2009
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