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Building Technologies
Basic Documentation LMV5...
CC1P7550en
19 O2 trim control with LMV52 and PLL52
22.05.2018
Then, the measured O2 ratio value is displayed. The pointer now indicates the
standardized value. By changing this value, the relative amount of air is reduced,
whereby the standardized value corresponds to the relative air rate reduction. The
standardized value is only changed until the actual O2 value reaches the required O2
setpoint, which is then displayed. The setting may only be confirmed after a constant
O2 value has been attained. The PC software will be useful for making checks.
P
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5
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:
2
.
0
S
t
a
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d
a
r
d
V
a
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:
1
5
.
3
Now, the operator must decide whether he wants to adopt or discard the settings.
P
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E
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At curvepoint
LowfireAdaptPtNo
and at the highest curvepoint, system adaption takes
place during the storage process. This is accomplished by measuring the delay time (
σ
)
of the boiler plant. Based on these values, the PI control parameters, the controller
locking time after load readjustment, and the min. value delay for the O2 alarm are
calculated. To measure the time constant (
σ
), the burner is driven back to the ratio
control curve. With the other curvepoints, the system returns to the ratio control curve
without adaption after setting the O2 setpoint. After setting all points, O2 trim control
can be activated.
19.11.6 Checking and changing the controller parameters
The adapted controller parameters and the measured time constant (
σ
) of the boiler can
be viewed on the
Controller parameters
↑
PI
menu, and changed, if required.
If the adapted Tau values are changed manually, the PI values determined from the
adaption remain unchanged. If these are to be recalculated based on the changed Tau
values, this can be done using the
Calc PI again
parameter.
The O2 setpoint must be between the O2 minimum value and the O2 ratio value.
