Specification Sheet

STV200/400KInstructionManual•9
Type1SPDs(surgearresters)shallbeinstalledasfollows:
1) Type1SPDs(surgearresters)shallbepermittedtobeconnectedtothe
supplysideoftheservicedisconnectaspermittedin230.82(4)or
2) Type1SPDs(surgearresters)shallbepermittedtobeconnectedas
speciedin285.24.
Wheninstalledatservices,Type1SPDsshallbeconnected
tooneofthefollowing:
1) Groundedserviceconductor
2) Groundingelectrodeconductor
3) Groundingelectrodefortheservice
4) Equipmentgroundingterminalintheserviceequipment

TheperformanceandsafetyofanySPDisdependentonpropergroundingand
bonding.Groundingisrequiredforsafety;correctimplementationalsoenhances
equipmentperformance.IncorrectgroundingcanreduceorimpedetheSPD’s
operation.AllelectricalcircuitstotheSPDmustincludeanequipment-grounding
conductorasrequiredbytheNECandlocalcodes.
Aninsulatedgroundingconductorisrequiredinadditiontoanymetallicraceway,
whichmaybeusedasagroundingconductor.ForparallelconnectedSPDs,
thegroundingconductorshouldbethesamewiresizeastheassociatedpower
conductors.Groundingconductorsmustberoutedwiththeassociatedpower
conductorsinthesameraceway(conduit).
Whenmetallicracewaysareused,adequateelectricalcontinuitymustbe
maintainedatallracewayconnections,particularlyracewayterminationstothe
electricalenclosures.Theuseofisolatingbushingsorothermeanstointerrupta
metallicconduitrunisapotentialsafetyhazardandisnotrecommended.
Surgeprotectivedevicesdonotdischargeallsurges
toground(earth).Surgeprotectivedevicesdivertthesurgecurrentbacktoits
sourcetocompletetheelectricalcircuit.Inthecaseoflightningwherepotential
isdevelopedwithrespecttotheearth,theSPDdivertsthesurgecurrenttothe
groundingelectrode(earthconnection).However,formosttransientsurgesthat
aredevelopedbyswitchingloads,theSPDdivertsthesurgecurrentbacktoits
sourcewithoutinvolvingthegroundingelectrode.
ForproperSPDperformance,theserviceentrancegroundingelectrodesystem
mustcomplywiththeNECbyhavingallavailableelectrodes(buildingsteel,
metalwaterpipe,drivenrods,concreteencasedelectrodes,etc.)properly
bondedtogetherandconnectedtothepowersystemgrounding.Theuseofa
separategroundingelectrodetogroundtheSPDdefeatstheeffectivenessof
theunit,isapotentialsafetyhazard,maycauseequipmentdamage,andisan
NECviolation(referenceNEC250.50).
Forproperandsafeoperation,theneutral(ifprovided)must
bereliablyconnectedtotheneutralofthesource.Failuretoprovideareliable
neutralconnectionmayresultinSPDmodulefailure.