Designation:B857−14StandardSpecificationforShapedWireCompactConcentric-Lay-StrandedAluminumConductors,Coated-SteelSupported(ACSS/TW)1ThisstandardisissuedunderthefixeddesignationB857;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoversshapedwirecompactconcentric-lay-strandedaluminumconductors,steelsupported(ACSS/TW)foruseasoverheadelectricalconductors(seeExplanatoryNote1).1.2Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.2.1Exceptions—ForconductorsizesdesignatedbyAWGorkcmilsizes,therequirementsinSIunitsarenumericallyconvertedfromthecorrespondingrequirementsininch-poundunits.ForconductorsizesdesignatedbySIunitsonly,therequirementsarestatedorderivedinSIunits.Fordensity,resistivity,andtemperature,thevaluesstatedinSIunitsaretoberegardedasstandard.1.3ACSS/TWisdesignedtoincreasethealuminumareaforagivendiameterofconductorbytheuseoftrapezoidalshapedwires(TW),ortoreducethediameterforagivenareaofaluminum.Theconductorsconsistofacentralcoreofroundsteelwire(s)surroundedbytwoormorelayersoftrapezoidalaluminum1350-0wires.Differentstrandingsofthesamesizeofconductorareidentifiedbytype,whichistheapproximateratioofsteelareatoaluminumareaexpressedinpercent(seeTable1,Table2,andTable3).Forthepurposeofthisspecification,thesizeslistedinTable1andTable2aretabulatedonthebasisofthefinishedconductorhavinganareaoroutsidediameterequaltothatofspecifiedsizesofstandardACSR,ACSS,andACSR/TWsoastofacilitateconductorselection.2.ReferencedDocuments2.1Thefollowingdocumentsoftheissueineffectondateofmaterialpurchaseformpartofthisspecificationtotheextentreferencedherein:2.2ASTMStandards:2B263TestMethodforDeterminationofCross-SectionalArea...
