1、Designation:D609701a(Reapproved 2008)1Standard Test Method forRelative Resistance to Vented Water-Tree Growth in SolidDielectric Insulating Materials1This standard is issued under the fixed designation D6097;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.1NOTEThe units statement in subsection 1.2 was corrected and the warning in old Note 2 was moved in
3、to the text of8.2 editorially in July 2008.1.Scope1.1 This test method covers the relative resistance to ventedwater-tree growth in solid translucent thermoplastic or cross-linked electrical insulating materials.This test method isespecially applicable to extruded polymeric insulation materi-als use
4、d in medium-voltage cables.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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 sta
5、ndard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitation prior to use.For specific hazardstatements see 8.1.1.4 There is no similar or equivalent IEC standard.2.Referenced Documents2.1 ASTM Standards:2D1898 Practice for Sampling of Plastic
6、s(Withdrawn 1998)3D1928 Practice for Preparation of Compression-MoldedPolyethylene Test Sheets and Test Specimens(Withdrawn2001)3D2275 Test Method for Voltage Endurance of Solid Electri-cal Insulating Materials Subjected to Partial Discharges(Corona)on the SurfaceD3756 Test Method for Evaluation of
7、Resistance to Electri-cal Breakdown by Treeing in Solid Dielectric MaterialsUsing Diverging Fields3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 water tree length(WTL),nthe maximum length of astained tree-like micro-channel path in millimetres,measuredfrom the tip of the conic
8、al defect in the direction of the conicalaxis.3.1.2 resistance to water-tree growth(RWTG)a dimen-sionless value which is L divided by the WTL.3.1.3 thickness of point-to-plane specimen(L),nthe ver-tical distance in millimetres from the tip of the conical defectto the opposite surface of the solid di
9、electric material.4.Summary of Test Method4.1 Ten compression-molded disk specimens,each contain-ing a conical-shaped defect,are subjected to an applied voltageof 5 kV at 1 kHz and 23 6 2C in an aqueous conductivesolution of 1.0 N NaCl for 30 days.This controlled conicaldefect is created by a sharp
10、needle with an included angle of60 and a tip radius of 3 m.The electrical stress at the defecttip is enhanced and can be estimated by the Masons Hyper-bolic point-to-plane stress enhancement equation.4This en-hanced electrical stress initiates the formation of a ventedwater-tree grown from the defec
11、t tip.Each treed specimen isstained and sliced.The water-tree length and point-to-planespecimen thickness measured under microscope are used tocalculate a ratio that is defined as the resistance to water-treegrowth.5.Significance and Use5.1 This is a laboratory test designed to simulate the growthof
12、 vented water-trees in the solid dielectric insulating material1This 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 May 1,2008.Published J
13、uly 2008.Originally approvedin 1997.Last previous edition approved in 2001 as D6097 01a.DOI:10.1520/D6097-01AR08E01.2For 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 s
14、tandards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4The sole source of supply of the base,Dow Corning 3110RTV,the catalyst,Dow Corning RTV Catalyst S,and the sealant,Dow Corning Multipurpose SiliconeSealant 732,known
15、to the committee at this time is Dow Corning,Inc.,Midland,MI48686.If you are aware of alternative suppliers,please provide this information toASTM International Headquarters.Your comments will receive careful consider-ation at a meeting of the responsible technical committe,which you may attend.Copy
16、right ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 initiated by a sharp protrusion at the insulating and conductiveinterface under a wet environment in a high electrical field.Water-treeing is the phenomenon which describes the appear-ance of tree-like growth in organic dielectrics under an ac fieldwhen exposed to moist environments.Two types of water-treesare formed.Bow tie trees(within the dielectric)and ventedwater-trees formed from condu
