Siemens LMV51.140C1 - Page 205

LMVSeriesTechnicalInstructions 
DocumentNo.LV5‐1000
SCCInc. Page33 Section6

AdditionalTipsforO
2
TrimCommissioningandTuning

 IftheAZL52displaysthattheO
2
trimhasbeenautomaticallydeactivated,itcanbere‐activated
underthefollowingmenupath:

Operation>O2Ctrlactivate

Repeateddeactivationscanbecause dbymanydifferentproblems,includinginaccurateload
numbers.

 AllofthepointsontheO
2
ControlCurveshouldbecompletedinonesession,andthesessionshould
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
2
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
2
RatioControlCurvemustalsohavea
correspondingpointontheO
2
ControlCurve.Ifthisisnotdone,animmediateO
2
trimdeactivation
willoccur.


 IfapointontheO
2
RatioControlCurveischanged(actuatorpositions),thecorrespondingpointon
theO
2
ControlCurvewillbedeleted.TheO
2
trimwillautomaticallydeactivateandcannotbere‐
activatedifpointsaremissingonanyofthecurves(O
2
RatioControl,O
2
Control,O
2
Alarm).

 Consideringtheitemsabove,ifonepointischangedontheO
2
RatioControlCurve,thentheO
2

RatioControlCurveandtheO
2
ControlCurveshouldberedonesothattheLambdaFactorateach
pointisknowntobebasedonthesameambientconditions. SettingtheO
2
RatioControlCurveand
theO
2
ControlCurveinapiecemealfashiontypicallydoesnotyieldreliable O
2
trimoperation.

 TheLMV52.240canonlydecreasetheairinfluencingactuatorpositionsbelowtheirsettingsonthe
O
2
RatioControlCurve.ThisistypicallynotanissueifthegapbetweentheO
2
RatioControlCurve
andtheO
2
ControlCurveislargeenough(1%).TheLMV52.440canincreaseordecreasetheair
influencingactuatorpositions,sothegapbetweentheO
2
RatioControlCurveandtheO
2
Control
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
2
RatioControl
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
2
trimto“O2Control”,soalockoutwilloccuriftheleanlimitisreached.

Params&Display>O2Contr/Alarm>Gas/OilSettings>OptgMode=O2Control

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