ASTM_D_5288_-_14.pdf

Designation:D528814Standard Test Method forDetermining Tracking Index of Electrical Insulating MaterialsUsing Various Electrode Materials(Excluding Platinum)1This standard is issued under the fixed designation D5288;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.Scope*1.1 This test method was developed using copper electrodesto evaluate the low-voltage(up to 600 V)tracking resistance ofmaterials in the presence of aqueous contaminants.2NOTE1At this time,only industrial laminates have been examinedusing this method,which was developed at the National ManufacturersElectrical Association(NEMA)laboratory located at the University ofCincinnati.It was found that a closer end point(less scatter)was obtainedthan with platinum electrodes,and materials tested tended to be ranked byresin system.1.1.1 It is acceptable to consider other electrode materialsfor use with this test method depending upon the application ofthe insulating material.1.2 This test method is similar to Test Method D3638,which determines the comparative tracking index of materialsusing platinum electrodes to produce the tracking on thespecimen surface.1.3 The values stated in metric(SI)units are the standard.The inch-pound equivalents of the metric units are approxi-mate.1.4 This standard is used to measure and describe theresponse of materials,products,or assemblies to heat andflame under controlled conditions,but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials,products,or assemblies underactual fire conditions.1.5 Fire testing is inherently hazardous.Adequate safe-guards for personnel and property shall be employed inconducting these tests.2.Referenced Documents2.1 ASTM Standards:3D618 Practice for Conditioning Plastics for TestingD1711 Terminology Relating to Electrical InsulationD3636 Practice for Sampling and Judging Quality of SolidElectrical Insulating MaterialsD3638 Test Method for Comparative Tracking Index ofElectrical Insulating Materials2.2 IEC Publication:4IEC 60112 Standard Method for the Determination of theProof and the Comparative Tracking Indices of SolidInsulating Materials,20033.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod and associated with electrical and electronic insulatingmaterials,use Terminology D1711.3.2 Definitions of Terms Specific to This Standard:3.2.1 track,na partially conducting path of localizeddeterioration on the surface of an insulating material.3.2.2 tracking,nthe process that produces tracks as aresult of the action of electric discharges on or close to aninsulation surface.3.2.3 tracking,contamination,ntracking caused by scin-tillations that result from the increased surface conduction dueto contamination.3.2.4 tracking index,TI,nan index for electrical insulat-ing materials which is arbitrarily defined as the numerical valueof that voltage which will cause failure by tracking when thenumber of drops of contaminant required to cause failure isequal to 50.1This 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 Nov.1,2014.Published December 2014.Originallyapproved in 1992.Last previous edition approved in 2010 as D5288 10.DOI:10.1520/D5288-14.2Mathes,K.N.,Chapter 4,“Surface Failure Measurements,”EngineeringDielectrics,Vol IIB,Electrical Properties of Solid Insulating Materials,Measure-ment Techniques,R.Bartnikas,Editor,ASTM STP 926,ASTM,Philadelphia,1987.3For 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.4Available from International Electrotechnical Commission(IEC),3 Rue deVaremb,Case postale 131,CH-1211,Geneva 20,Switzerland,http:/www.iec.ch.*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 States1 3.2.4.1 DiscussionThis value is obtained from a plot ofthe number of drops required to cause failure by trackingversus the applied voltage.3.2.5 tracking indexcopper electrodes,TI-Cu,na track-ing index test using copper electrodes.3.2.5.1 DiscussionThis test is comparable to comparativetracking index,Test Method D3638,with the following excep-tions:(1)copper electrodes are used instead of platinum,and(2)the electrodes may have to be re-ground after every testbecause of the softness of copper.3.2.6 tracking resistance,nthe quantitative expression ofthe voltage and the time required to develop a track underspecified conditions.4.Summ