Basic Documentation

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Siemens Modular Heating Controller RMH760B CE1P3133en
Building Technologies 6 Boiler temperature control 2017-09-29
Through the generation 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 will be locked earlier.
When the reset integral (area "b" in the diagram) reaches the set value of the reset
integral of stage 2 (point in time t
reset
), stage 2 will be locked and the basic stage switched
off.
1
0
INT
max.
RlsBuSt2
1
0
BuSt2
t
RlsINT
3133D15
0
1
0
t
t
t
t
BuSt1
max.
TBoSrtpt +
1
/
2
SDBo
TBo
RstINT
TBoSetpt -
1
/
2
SDBo
RstINT
BuSt1
Burner stage 1
SD
Switching differential
BuSt2
Burner stage 2
Setpt
Setpoint
INT
Integral
t
Time
RlsBuSt2
Release of burner stage 2
TBo
Boiler temperature
Rst
Reset
If, with stages 1 and 2 released, both stages are locked at the same time, the basic
stage will be switched off with a delay of 10 seconds. Switching off in 2 stages also
reduces the pressure shocks in the gas supply line. This prevents unnecessary lockout
in the case of large boiler outputs.
6.5.4 Control of modulating burners
Main menu > Commissioning > Settings > … or
Main menu > Settings > Boiler > Burner modulating
Operating line
Range
Factory setting
Actuator run time
1…600 s
60 s
P-band Xp
1…200 K
20 K
Integral action time Tn
0…600 s
150 s
Derivative action time Tv
0…30 s
20 s
Modulating burners only modulate above a certain level. For standard forced draft
burners, this level is at about 30 to 40 % of the rated capacity.
Note