ASTM_D_3638_-_21e1.pdf

Designation:D3638211Standard Test Method forComparative Tracking Index of Electrical InsulatingMaterials1This standard is issued under the fixed designation D3638;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.1NOTESubsections 7.1.1,7.1.2,and 9.4 were corrected editorially in January 2022.1.Scope*1.1 This test method evaluates in a short period of time thelow-voltage(up to 600 V)track resistance or comparativetracking index(CTI)of materials in the presence of aqueouscontaminants.1.2 The values stated in metric(SI)units are to be regardedas standard.The inch-pound equivalents of the metric units areapproximate.1.3 This test method is technically equivalent to the versionof IEC Publication 112 cited in 2.2.However,the 2007 versionof IEC 60112 Fourth Edition yields numerical CTI values thatare very likely to differ significantly from this test method.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 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 to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1711 Terminology Relating to Electrical InsulationD6054 Practice for Conditioning Electrical Insulating Mate-rials for Testing(Withdrawn 2012)32.2 IEC Publications:4IEC 112 Method for the determination of the proof and thecomparative tracking indices of solid insulating materialsIEC 60112 Method for the determination of the proof and thecomparative tracking indices of solid insulating materialsIEC 60664-1 Insulation coordination for equipment withinlow-voltage supply systems Part 1:Principles,require-ments and tests,2020 Edition 3.02.3 2.3 ANSI/UL Publication:5ANSI/UL 840 Standard for Insulation Coordination Includ-ing Clearances and Creepage Distances for ElectricalEquipment.January 6,2005,3rdedition3.Terminology3.1 Definitions:3.1.1 track,na partially conducting path of localizeddeterioration on the surface of an insulating material.3.1.2 tracking,nthe process that produces tracks as aresult of the action of electric discharges on or close to aninsulation surface.3.1.3 tracking,contamination,ntracking caused by scin-tillations that result from the increased surface conduction dueto contamination.3.1.4 tracking resistance,nthe quantitative expression ofthe voltage and the time required to develop a track under thespecified conditions.3.1.5 For other terminology,refer to Terminology D1711.3.2 Definitions of Terms Specific to This Standard:1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.12 on Electrical Tests.Current edition approved Jan.1,2021.Published February 2021.Originallyapproved in 1977.Last previous edition approved in 2012 as D3638 12.DOI:10.1520/D3638-21E01.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from International Electrotechnical Commission(IEC),3,rue deVaremb,1st floor,P.O.Box 131,CH-1211,Geneva 20,Switzerland,https:/www.iec.ch.5Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,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.13.2.1 comparative tracking index,nan index for electricalinsulating materials which is arbitrarily defined as the numeri-cal value of that voltage which will cause failure by trackingwhen the number of drops of contaminant required to causefailure is equal to 50.3.2.1.1 DiscussionThe voltage value is obtained from aplot of the number of drops required to cause failure bytracking versus the applied voltage.3.2.2 failure,nan attribute of an elec