Traveling To The Operating Position; Operation; End Of Operating Position; Postpurging - Siemens LMV51 Series Basic Documentation

Traveling to the
operating position

Operation

End of operating
position

Postpurging

Actuator speed outside
normal operation
Note
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When ignition has taken place and the flame has stabilized, the actuators must be brought
into line. For that purpose, the control unit drives the actuators to their basic part load
position (low-fire) as defined by the curves.
The actuators which, for ignition, have assumed a special position, travel at individually
calculated speeds to ensure that all of them will reach the part load position at the same
time.
90°
0°
7550d03E/0202
25 %
Low fire
Traveling to the low-fire position after ignition
Note: The system also permits ignition positions that lie outside the range defined by
fuel / air ratio control, that is, not between high-fire and low-fire.
In the operating position, the dampers are adjusted according to demand. The ratio curves
are defined for gas and oil.
For modulating operation, the output can be adjusted in increments of 0.1°.
The actuators travel to the defined ratio curves.
In multistage operation, 2 or 3 load points can be approached.
For more detailed information, refer to section «Operating position».
After there is no more demand from the controller, the fuel / air ratio control system first
changes to low-fire (Phase 62) before the fuel valve close. For that purpose, a maximum
time is available which can be parameterized ® part load shutdown.
When the burner is shut down, the actuators will be driven to their postpurge positions in
Phase 72.
For that purpose, a maximum time is available ® position check.
The postpurge position is defined for all actuators and can be adjusted depending on
the type of fuel.
Parameter: PostpurgePosAir
Parameter: PostpurgePosGas or parameter
Parameter: PostpurgePosAux
The actuators' speed when traveling to the home, prepurge, ignition and postpurge
positions can be parameterized.
Parameter: TmeNoFlame
Outside normal operation, all actuators travel at that speed.
When parameterizing the operating ramp, the speed of the slowest actuator must be
taken into consideration!
Basic Documentation LMV51...
4 Fuel / air ratio control (FARC)
50 % 75 % 100 %
Ignition positions
Load
PostpurgePosOil
CC1P7550en
29.05.2002