Adjustment Of Output; Entering The Operating Position; Operating Position - Siemens LMV37.4 Series Basic Documentation

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10.4.3 Adjustment of output

When the output increases, the LMV37.4 moves from the curvepoint of stage 1 (P1) to
the switch-on point of stage 2 (P2on). If the switch-on point is exceeded, the valve for
the second stage is switched on. Then, the LMV37.4 moves to the curvepoint for stage
2 (P2). When the output decreases, the LMV37.4 moves from the curvepoint of stage 2
(P2) to the switch-off point of stage 2 (P2of). If this point is crossed, the valve for the
second stage is switched off. Then, the LMV37.4 moves to the curvepoint for stage 1
(P1).
In 3-stage operation, the output between stage 2 and stage 3 is adjusted analogously to
2-stage operation. As static outputs, only P1, P2 and P3 can be approached.
The switch-on and switch-off points are crossed only when changing between stages.
The traveling speeds are fixed. Depending on the positioning angles to be covered, air
actuator and VSD do not reach the operating or switch-on/switch-off points at the same
time. The valves are switched on / off only after the actuators have reached their correct
positions.
When parameterizing the curves, the switch-on points can also be approached in a
stationary manner. In addition, when setting the curve via P2_d (P3_d), curvepoint P2
(P3) can be readjusted without traveling to it. In that case, the LMV37.4 is at the
respective switch-on point. This procedure is used to reduce the operating time if there
is shortage of air.
Figure 76: Adjustment of output

10.4.4 Entering the operating position

The burner is ignited at ignition position P0. When entering operating phase 60, the
actuators are driven from ignition position P0 to the operating point of stage 1 (P1) at the
respective traveling speed.

10.4.5 Operating position

In the operating position, the burner's output can be adjusted between operating points
P1 and P2 or P3 in accordance with the load controller's presetting, as described in
chapter Adjustment of output. Ignition position P0 is not approached anymore. It can
only be reached via curve adjustment.
Basic documentation LMV37.4...
10 Electronic ratio control
CC1P7546en
17.12.2018