ASTM_B_496_-_16.pdf

Designation:B49616Standard Specification forCompact Round Concentric-Lay-Stranded CopperConductors1This standard is issued under the fixed designation B496;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 Thisspecificationcoversbarecompactroundconcentric-lay-stranded conductors made from uncoated roundcopper wires for general use for electrical purposes.Theseconductors shall be constructed with a central core surroundedby one or more layers of helically laid compacted wires(Explanatory Note 1 and Note 2).1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.2.1 For density,resistivity,and temperature,the valuesstated in SI units are to be regarded as standard.2.Referenced Documents2.1 The following documents of the issue in effect on dateof material purchase form a part of this specification to theextent referenced herein:2.2 ASTM Standards:2B3 Specification for Soft or Annealed Copper WireB263 Test Method for Determination of Cross-SectionalArea of Stranded ConductorsB354 Terminology Relating to Uninsulated Metallic Electri-cal Conductors3.Ordering Information3.1 Orders for material under this specification shall includethe following information:3.1.1 Quantity of each size(Table 1),3.1.2 Conductor size;circular-mil area or AWG,(Section 6and Table 1),3.1.3 Packaging(Section 15),if required,3.1.4 Special package marking,and3.1.5 Place of inspection(Section 14).4.Joints4.1 Welds and brazes may be made in rods or in wires priorto final drawing.4.2 Welds and brazes may be made in the individual rounddrawn wires for compact conductors,but shall not be closertogether than 1 ft(300 mm)for conductor of 19 wires or lessor closer than 1 ft(300 mm)in a layer for conductor of morethan 19 wires.4.3 No joint nor splice shall be made in a compact-strandedconductor as a whole.5.Lay5.1 The length of lay of the outer layer shall not be less than8 nor more than 16 times the outside diameter of the completedconductor.The maximum length of lay for compact conductorsAWG 2(33.6 mm2)and smaller shall be 17.5 times the outsidediameter of the conductor.5.2 The direction of lay of the outer layer shall be left-hand,and it shall be reversed in successive layers,unidirectional,orunilay.6.Construction6.1 The construction of the compact round concentric-lay-stranded conductors shall be as shown in Table 1.6.2 The starting round copper wires used in the fabricationof the compact round conductor shall be of such diameter as toproduce a finished conductor having a nominal cross-sectionalarea and diameter as prescribed in Table 1.7.Density7.1 For the purpose of calculating linear densities,crosssections,and so forth,the density of the copper shall be takenas 8.89 g/cm3(0.32117 lb/in.3)at 20C.8.Mass and Resistance8.1 The mass per unit length and dc electrical resistance ofa compact round conductor are greater than the total of thesecharacteristics of the compressed wires composing the finished1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.04 onConductors of Copper and Copper Alloys.Current edition approved April 1,2016.Published May 2016.Originallyapproved in 1969.Last previous edition approved in 2014 as B496 14.DOI:10.1520/B0496-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 conductor,depending upon the lay.The standard increment ofmass per unit length and electrical resistance shall be taken as2%.The nominal mass per unit length and dc resistance areshown in Table 1.When the dc resistance is measured at otherthan 20C,it shall be corrected by using the multiplying factorsgiven in Table 2.8.2 In cases where the lay is definitely known,the incrementmay be calculated if desired(Explanatory Note 3).8.3 For conductors to be used in covered or insulated wiresor cables,direct current(DC)resistance measurement may beused instead of the method outlined in Section 9,to determinecompliance with this specification.9.Variation in Area9.1 The cross-sectional area of the compact round conductorshall be not less than 98%of the cross-sectional area asspecified in Column 1 of Table 1.9.2 The manufacturer shall determine the cross-sectionalarea by Test Method B263.In applying this method,theincrement in mass per unit length resulting from stranding maybe the a