TechnicalInstructions LMVSeries
DocumentNo.LV5‐1000
Section6 Page20SCCInc.
PostCommissioningTuning
AftertheO
2
curveshavebeensetupaccordingtotheproceduresabove,someadditionalburner/boiler
specifictuningmaybenecessarytokeeptheO
2
trimoperatingproperly.Whenandhowtousethese
tuningparametersisdiscussedbelow.
LoadCtrlSuspend‐ThissetstheloadchangethatisnecessarytomaketheO
2
trimtransitionfromactive
O
2
trimtopre‐control.Manyfactorsinfluencethesettingofthisparameter.
Menupath:Params&Display>O2Contr/Alarm>GasSettings>ControlParam
Highersettings(moreactivetrim,lesspre‐control)canhelptheO
2
trimstayclosetosetpointinthe
followingsituations:
1. TheO
2
ControlCurveisrelativelyflatfromlowfiretohighfire(varieslessthan0.5%O
2
)
2. Themodulationramptimeisslow(OperatRampModissetto60seconds ormore)
3. Thedelaytime(Tautime)oftheboilerisrelativelyfast(TauLow‐Fireissetto7secondsorless)
Lowersettings(lessactivetrim,morepre‐control )canhelptheO
2
trimstayclosetosetpointinthe
followingsituations:
1. TheO
2
ControlCurveslopesfromlowfiretohighfire(variesmorethan0.5%O
2
)
2. Themodulationramptimeisfast(OperatRampModissetto30seconds)
3. Thedelaytime(Tautime)oftheboilerisslow(TauLow‐Fireissetformorethan7seconds)
O2TrimBehavior‐IfparameterStartmodeissetto“standard”,thissettingcontrolshowtheO
2
trim
respondsifthemeasuredO
2
valuestartstomoveawayfromtheO
2
setpointsignificantly.
Menupath:Params&Display>O2Contr/Alarm>GasSettings>ControlParam
1. Asettingof“ForcedAirAdd”willhelpifdeactivationsareduetotherichlimit(O
2
alarm)sinceairwill
beaddedmoreaggressively.
2. Asettingof“ForcedAirRed”willhelpifdeactivationsareduetothelean limit(O2MaxValue)since
airwillbesubtractedmoreaggressively.
3. Asettingof“symmetric”isusedwhentherichlimit(O
2
alarm)andtheleanlimit(O2MaxValue)are
relativelyclosetogether,andanaggressivecorrectioninonedirectionmightcauseadeactivation
duetotheotherlimit.
NOTE:OnanLMV52.440withtheStartModesettosomethingotherthan“standard”,thesettingof
O2TrimBehaviorhasnoeffect.
O2ModOffset‐Duringalo
adchangewhenthepre‐controlbecomesactive(seeLoadCtrlSuspend),this
willtemporarilyaddmoreair
beyondwhatisprescribedbytheLambdaFactor.Increasingthissetting
canhelpwithrichlimit(O
2
alarm)deactivationsduringmodulation,butthisparametershouldnotbe
usedasasubstituteforproperO
2
trimcommissioningprocedures.
Menupath:Params&Display>O2Contr/Alarm>GasSettings>ControlParam