Siemens LMV5 Series Technical Instructions page 205

LMV Series
Additional Tips for O Trim Commissioning and Tuning
2

If the AZL52 displays that the O
under the following menu path:
Operation > O2Ctrl activate
Repeated deactivations can be caused by many different problems, including inaccurate load
numbers.

All of the points on the O
be less than an hour. This is preferable, since ambient conditions (air temperature and barometric
pressure) typically do not change a significant amount in one hour.

Every point on the O Ratio Control Curve must have a corresponding point on the rich limit (O
2
alarm) curve. For Point 2 and above, every point on the O
corresponding point on the O
will occur.

If a point on the O Ratio Control Curve is changed (actuator positions), the corresponding point on
2
the O Control Curve will be deleted. The O
2
activated if points are missing on any of the curves (O

Considering the items above, if one point is changed on the O
Ratio Control Curve and the O
point is known to be based on the same ambient conditions. Setting the O
the O Control Curve in a piecemeal fashion typically does not yield reliable O
2

The LMV52.240 can only decrease the air influencing actuator positions below their settings on the
O Ratio Control Curve. This is typically not an issue if the gap between the O
2
and the O Control Curve is large enough (1%). The LMV52.440 can increase or decrease the air
2
influencing actuator positions, so the gap between the O
Curve can be smaller (0.5%). This also gives the LMV52.440 the ability to deal with more challenging
applications such as FGR and low NOx mesh burners.

Most burners will flame fail in a safe way if operated too lean. However, overly lean operation may
be hazardous for some burner designs. If one of these burners is encountered, the O
Curve can be set to function as the lean limit using the following menu path:
Params & Display > O2Contr/Alarm > Gas/Oil Settings > O2 Alarm > Type O2 MaxValue
Set this to "O2MaxCurve". For this type of burner it is also recommended to set the operating mode
of the O trim to "O2 Control", so a lockout will occur if the lean limit is reached.
2
Params & Display > O2Contr/Alarm > Gas/Oil Settings > OptgMode = O2 Control
SCC Inc.
trim has been automatically deactivated, it can be re‐activated
2
Control Curve should be completed in one session, and the session should
2
Control Curve. If this is not done, an immediate O
2
trim will automatically deactivate and cannot be re‐
2
Control Curve should be redone so that the Lambda Factor at each
2
Page 33
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Document No. LV5‐1000
Ratio Control Curve must also have a
2
Ratio Control, O Control, O
2 2
Ratio Control Curve, then the O
2
Ratio Control Curve and
2
trim operation.
2
Ratio Control Curve
2
Ratio Control Curve and the O
2
Technical Instructions
2
trim deactivation
2
Alarm).
2
2
Control
2
Ratio Control
2
Section 6