ASTM_B_787_-_B_787M_-_04_2014.pdf

Designation:B787/B787M04(Reapproved 2014)Standard Specification for19 Wire Combination Unilay-Stranded Copper Conductorsfor Subsequent Insulation1This standard is issued under the fixed designation B787/B787M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers bare combination unilay-stranded conductors made from round copper wires,eitheruncoated or coated with tin or lead alloy for insulated conduc-tors for electrical purposes.These conductors shall be con-structed with a central core wire surrounded by two layers ofhelically laid wires,resulting in an outer diameter equal to thecompressed-stranded equivalent conductor.(See ExplanatoryNote 1 and Note 2).NOTE1For the purpose of this specification,combination unilayconductor is defined as follows:a central core wire surrounded by a layerof six helically laid wires of the same diameter as the core wire with ahelically laid outer layer containing six smaller wires alternated betweensix wires of the same diameter as the wires in the layer underneath.Bothlayers have a common length and direction of lay(see Fig.1).1.2 For the purpose of this specification,normal conductorclassification(Class AA,A,B,C)is not applicable as theseconductors are intended for subsequent insulation.The descrip-tive term combination unilay-stranded shall be used in place ofconductor classification.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3.1 For conductor sizes designated by AWG or kcmil,therequirements in SI units have been numerically converted fromcorresponding values,stated or derived,in inch-pound units.1.3.2 For conductor sizes designated by SI units only,therequirements are stated or derived in SI units.1.3.3 For density,resistivity,and temperature,the valuesstated in SI units are to be regarded as standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.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:2B1 Specification for Hard-Drawn Copper WireB2 Specification for Medium-Hard-Drawn Copper WireB3 Specification for Soft or Annealed Copper WireB33 Specification for Tin-Coated Soft or Annealed CopperWire for Electrical PurposesB189 Specification for Lead-Coated and Lead-Alloy-CoatedSoft Copper Wire for Electrical PurposesB246 Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical PurposesB263 Test Method for Determination of Cross-SectionalArea of Stranded ConductorsB354 Terminology Relating to Uninsulated Metallic Electri-cal Conductors2.3 Other Standard:3NBS Handbook 100 Copper Wire Tables of the NationalBureau of Standards3.Ordering Information3.1 Orders for materials under this specification shall in-clude the following information:3.1.1 Quantity of each size,3.1.2 Conductor Size:Circular-mil area or American WireGage,AWG(Section 7 and Table 1),3.1.3 Stranding(see Explanatory Note 3),3.1.4 Temper(see 4.2),3.1.5 Whether coated or uncoated;if coated,designate typeof coating(see 4.1 and 4.2),1This 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 Sept.1,2014.Published September 2014.Originallyapproved in 1988.Last previous edition approved in 2009 as B787/B787M 04(2009).DOI:10.1520/B0787_B0787M-04R14.2For 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.3Available from National Institute of Standards and Technology(NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 20899-1070,http:/www.nist.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.6 Details of special-purpose lays,if required(see 6.2),3.1.7 When physical tests shall be made(see 9.2 and 9.3),3.1.8 Package size(see 15.1),3.1.9 Lagging,if required(see 15.2),3.1.10 Special package marking,if required(Section 15),and3.1.11 Place of inspection(Section 13).4.Requirements for Wires4.1 The purchaser shall de