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Building Technologies
Basic Documentation LMV5...
CC1P7550en
19 O2 trim control with LMV52 and PLL52
22.05.2018
Load at which a system is ignited with O2 trim control and
Startmode
parameter set to
Ign Load TC.
Parameter
Gas:
Load of Ignition
Oil:
Load of Ignition
19.4.6 Initializing and release of the O2 trim controller
Parameter setting
standard
With this setting, the LMV52 behaves as it did before this parameter was introduced.
The burner is started with the O2 trim controller locked and is put into operation along
the safe ratio control curves.
The locking time for startup commences when operating phase 60 is entered.
It is defined as a multiple of the
Tau Low-Fire
value using the
NumberTauSuspend
parameter (
NumberTauSuspend
x
Tau Low-Fire)
.
Once this locking time has passed, the O2 trim controller is initialized and after a further
4 x
Tau Low-Fire
released.
The
dynamic release criterion
then becomes active (refer to chapter
Behavior in the
event of load changes
).
For initialization, the start value of the manipulated variable is calculated.
An offset is added to this, which is defined using the
O2ModOffset
parameter.
Parameter NumberTauSuspend
Gas:
O2ModOffset
Oil:
O2ModOffset
Β
Note!
Parameter
O2Offset
has been renamed to
O2ModOffset.
O2 ratio control (actual)
O2 ratio control (setting time)
O2 setpoint
Load
Influencing factor
for setting time
(standardized value)
Influencing factor
initializing
75
50
d4
2e
/1
01
2
Figure 118: Initializing the O2 trim controller