1、Designation:B78401(Reapproved 2017)1Standard Specification forModified Concentric-Lay-Stranded Copper Conductors forUse in Insulated Electrical Cables1This standard is issued under the fixed designation B784;the number immediately following the designation indicates the year oforiginal adoption or,i
2、n 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.1NOTETypos in Section 1 were corrected editorially in April 2017.1.Scope1.1 This specification cove
3、rs bare modified concentric-lay-stranded conductors made from round copper wires,eitheruncoated or coated with tin,lead,or lead alloy for general usein insulated electrical cables.These conductors shall be con-structed with a central core consisting of not more than sevenwires,surrounded by one or m
4、ore layers of helically laid wires.1.2 For the purposes of this specification,conductors areclassified as follows(Explanatory Note 1 and Note 2):1.2.1 Class B ModifiedConductors to be insulated withvarious materials such as rubber,paper,and crosslink polyeth-ylene.1.2.2 Class C Modified and Class D
5、ModifiedConductorswhere greater flexibility is required than is provided by ClassB Modified conductors.1.3 The values stated in inch-pound or SI units are to beregarded separately as standard.Each system shall be usedindependently of the other.Combining the values from the twosystems may result in n
6、on-conformance with the specification.For conductor sizes designated by AWG or kcmil sizes,therequirements in SI units are numerically converted from thecorresponding requirements in inch-pound units.For conductorsizes designated byAWG or kcmil,the requirements in SI unitshave been numerically conve
7、rted from corresponding valuesstated or derived in inch-pound units.For conductor sizesdesignated by SI units only,the requirements are stated orderived in SI units.1.3.1 For density,resistivity and temperature,the valuesstated in SI units are to be regarded as standard.NOTE1The significant differen
8、ces in this specification from Specifi-cation B8 are as follows:(1)The central core is permitted to contain up toseven wires drawn into the assembly with an infinite length of lay whileSpecification B8 permits only one,and(2)The construction is applicableonly to stranded assemblies of 19 or more wir
9、es.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers
10、to Trade(TBT)Committee.2.Referenced Documents2.1 The following documents of the issue in effect at thedate of material purchase form a part of this specification to theextent referenced herein.2.2 ASTM Standards:2B3 Specification for Soft or Annealed Copper WireB8 Specification for Concentric-Lay-St
11、randed CopperConductors,Hard,Medium-Hard,or SoftB33 Specification for Tin-Coated Soft or Annealed CopperWire for Electrical PurposesB189 Specification for Lead-Coated and Lead-Alloy-CoatedSoft Copper Wire for Electrical PurposesB263 Test Method for Determination of Cross-SectionalArea of Stranded Co
12、nductorsB354 Terminology Relating to Uninsulated Metallic Electri-cal Conductors2.3 Other Standard:NBS Handbook 10033.Ordering Information3.1 Orders for material under this specification shall includethe following information:3.1.1 Quantity of each size and class,3.1.2 Conductor size:circular-mil ar
13、ea or American WireGage(AWG)(Section 6),3.1.3 Class(see 1.2 and Table 1),3.1.4 Temper(see 10.2),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
14、 approved April 1,2017.Published April 2017.Originallyapproved in 1988.Last previous edition approved in 2012 as B784 01(2012).DOI:10.1520/B0784-01R17E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStand
15、ards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Available from National Technical Information Service(NTIS),5301 Shawnee Rd.,Alexandria,VA 22312,http:/www.ntis.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken
16、,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 3.1.5 Whether coated or uncoated;if coated,designate typeof coating(see 10.1 and 10.2),3.1.6 Details of special-purpose lays,if required(see 5.2),3.1.7 Lagg