Siemens LMV52.440B1 - Pre-Requisites for LMV52 Systems with a VFD

TechnicalInstructions  LMVSeries
DocumentNo.LV5‐1000
Section4 Page4 SCCInc.
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7. Amethodofdeterminingfiringrate(fuelflowwithin+/‐5%)shouldbeused.This,in
combinationwithknowledgeofhighfireand turndown,isusedtosettheloadnumbersoneach
curvepoint.AnExcelspreadsheetisavailableforthispurpose.
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8. Forsteamboilers,thefeedwatersupp lymustbeadequatetosupporthighfireoperation
.
Feedwatercontrolsmustbeworkingproperly.
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9. Theloadontheboilermustbeadequatesothataburner/boilercombinationcanberunat
highfireforaminimumof5minutes.
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Pre‐RequisitesforLMV52SystemswithaVFD
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1. Allpre‐requisitesoftheBasicLMV51systemapply.
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2. Blowermotorspeedsensorandspeedwheelmustbeinstalledcorrectly. SeeAppendixB(LMV5
AccessoriesGuide)formoredetails.
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3. Vector‐typeVFDsarehighlyrecommendedduetotheirinherentlymoreprecisemotorspeed
control.Volt/HzVF
Dsarenotrecommendedduetolessprecises
peedcontrol.
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4. PropergroundingbetweentheLMV5,theVFD,andthemotormustbeinstalled.SeeSection2
(Wiring)formoredetails.
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5. VFDparametersmustbesetcorrectlytobecompatiblewithboththeLMV52andtheblower
motor.SeeSection5(VSD)formoredetails.Particularattentionshoul
dbepaidtothe
following:
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a. Analogsignalconfiguration.BoththeLMV52andVFDmustbeconfiguredfora4‐20mA
signal.
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b. RampratesbetweentheLMV52andtheVFDmustbecompatible.Ingeneral,ramp
ratesoftheVF
Dshouldbe10secondslessthantheLMV52.
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c. VFDmustbesetupasaslaveunitfora4‐20mAsignal.Damping,deadba
nd,andPID
functionsmustbedisabled.
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d. Thefrequency(Hz)output ofthedrivemustbedirectlyproportionaltotheanaloginput
signal.
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e. Acceleration/decelerationcurvesmustbelinearinsteadof“S‐
shaped”.
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f. Rampsettingsmustberampup/rampdowninsteadoframpup/coastdown.
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g. AnytypeofdampingorstallpreventionintheVFDshouldbedeactivated.
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