Multistage Operation; Definition Of Curves; Traveling Speed - Siemens LMV27.100x2 Basic Documentation

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10.4

Multistage operation

This operating mode is only available when firing on oil. There is a choice of 2-stage and
3-stage operation. Hence, the burner's output can be modulated via 2 or 3 stages.
Modulation is accomplished by adjustment of the air actuator and by switching the fuel
valves for adjusting the amount of fuel.
10.4.1

Definition of curves

Air-fuel ratio control is defined via the 2 or 3 static output points. To switch the valves on
and off, switch-on and switch-off points must be defined.
The following assignments apply:
Curve- Meaning
point
P0 Point of ignition (not approached in the operating position)
P1 Stage 1
P2on Switch-on point stage 2. When the angle exceeds this point, the
fuel valve for the second stage is switched on
P2_d Presetting of point P2 with no approach
P2 Stage 2
P2of Switch-off point stage 2. When the angle falls below this point, the
fuel valve for the second stage is switched off
P3on Switch-on point stage 3. When the angle exceeds this point, the
fuel valve for the third stage is switched on
P3_d Presetting of point P3 with no approach
P3 Stage 3
P3of Switch-off point stage 3. When the angle falls below this point, the
fuel valve for the third stage is switched off
The actuator positions can be set with a resolution of 0.1°.

10.4.2 Traveling speed

The defined ramp speeds are used.
The setting also acts outside the running position.
The running speed of the actuators is fixed at 5 seconds for a positioning angle of 90°
for SQM33.4, SQM33.5, and SQN1.
The speed is 10 seconds for a positioning angle of 90° for SQM33.6.
The SQM33.7 requires 17 seconds for a positioning angle of 90°.
Basic Documentation LMV27...
10 Electronic air-fuel ratio control
Valve
V1
V1
V1
V1
V2
V2
V2
V2
V3
V3
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17.12.2018