Siemens LMV5 Series Technical Instructions page 177

LMV Series
4. O Control ‐ This is the setpoint of the O
2
This is also commonly referred to as the "trim curve".
5. O Alarm ‐ This is the rich O
2
must have a corresponding O
"rich alarm".
6. O Max Value ‐ This is the lean O
2
the "lean alarm".
7. Lambda Factor ‐ A value that is learned by the LMV52 for each point on the curve except Point 1.
This value is learned when the O
responds when the burner is being transitioned from an O
point during O Control commissioning. This value represents how much the air flow needs to be
2
changed to get a change in the measured %O
an O trim perspective.
2
8. Fuel Rate – This is the percentage of high fire fuel flow and is also referred to as the firing rate. This
is also the same as the "Load" number seen during Ratio Control Curve commissioning. For a 10‐to‐
1 turndown burner, high fire would be 100% and low fire would be 10%. For a 4‐to‐1 turndown
burner, high fire would be 100% and low fire would be 25%. For O
important that the fuel rate (load number) matches the actual fuel flow to the burner within +/‐ 3%.
9. Air Rate ‐ When no O
as the fuel rate. This is also known as the air flow. For example, a 10‐to‐1 turndown burner running
at Point 5 on the Ratio Control Curve will have a fuel rate of 50% and an air rate of 50%. If the O
trim is engaged and the O
relative to the fuel rate until the setpoint is achieved.
10. Standardized Value ‐ This is a percentage reduction of the air rate and is used when the O
Curve is being set. For example, if the air rate is 50%, and a Standardized Value of 10% is entered,
the air rate will be reduced to 45%. The math would be: (50% * 10% = 5%), then (50% ‐5%) = 45%.
11. Pre‐Control ‐ When large load changes occur during modulation, this will engage and temporarily
disable the closed‐loop O
Lambda Factor to predict how the burner will react when modulating. Pre‐control is necessary for
burners where the O
2
SCC Inc.
trim system for each point on the curve except Point 1.
2
limit for each point. Every Fuel‐Air Ratio Curve point including Point 1
2
alarm point. This is also commonly referred to as the "rich curve" or
2
limit, and is a single value for all points. This is also referred to as
2
control curve is being set, and is based on how the measured %O
2
, and is essentially the "signature" of the burner from
2
trim is taking place (running on Ratio Control Curve), the air rate is the same
2
sensor reads values higher than setpoint, the air rate will be reduced
2
trim. This temporary "open‐loop" trim is based on using a correct
2
setpoint is not constant from low fire to high fire.
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Ratio Control point to the O
2
trim systems, it is very
2
Technical Instructions
Document No. LV5‐1000
2
Control
2
2
Control
2
Section 6