Multistage Operation - Siemens LMV50 Series Manual

Multistage
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6.4.9 Multistage operation

Multistage operation is only possible when firing on oil. It is possible to parameterize if
multistage or modulating operation is used.
Electronic fuel-air ratio control can be configured for both 2-stage and 3-stage burners.
In this operating mode, the oil actuator is not controlled.
Multistage fuel-air ratio control is defined via different load points. These are the
stationary operating points and separately adjustable switch-on/off points.
Pos.
7550d02E
S1
Figure 39: Multistage operation (here: 2-stage)
Between these points, the actuators are adjusted during their continuous travel. The
speeds of the individual actuators are calculated such that they reach their targets at
the same time.
Note!
When parameterizing the multistage operating ramp, the speed of the slowest
actuator must be taken into consideration!
When changing from stage 1 to stage 2, switch-on point S2 is approached first, starting
from operating point S1. Now, the second fuel valve is opened.
Then, the system is driven to operating point S2.
If the output shall be cut back to stage 1, switch-off point S2 is approached first.
If switch-off point S2 has not yet been set, switch-on point S2 is approached and the
fuel valve closed.
Then, the fuel-air ratio position of operating point S1 is approached again.
The procedure is analogous when switching from stage 2 to stage 3, and back again.
Parameter Operation Mode (2-stage / 3-stage / modulating)
Curve Settings (curve position stage: Stage 1...3 and on
and off switching points)
Betr_Rampe_Stuf
Basic Documentation LMV5...
6 Fuel-air ratio control (FARC)
S2on S2off S2
Load
CC1P7550en
22.05.2018