ASTM_D_2275_-_14.pdf

Designation:D227514Standard Test Method forVoltage Endurance of Solid Electrical Insulating MaterialsSubjected to Partial Discharges(Corona)on the Surface1This standard is issued under the fixed designation D2275;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.Scope1.1 This test method determines the voltage endurance ofsolid electrical insulating materials for use at commercialpower frequencies under the action of corona(see Note 1).Thistest method is more meaningful for rating materials withrespect to their resistance to prolonged ac stress under coronaconditions for comparative evaluation between materials.NOTE1The term“corona”is used almost exclusively in this testmethod instead of“partial discharge,”because it is a visible glow at theedge of the electrode interface that is the result of partial discharge.Corona,as defined in Terminology D1711,is“visible partial discharges ingases adjacent to a conductor.”1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.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 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD618 Practice for Conditioning Plastics for TestingD1711 Terminology Relating to Electrical InsulationD1868 Test Method for Detection and Measurement ofPartial Discharge(Corona)Pulses in Evaluation of Insu-lation SystemsD3382 Test Methods for Measurement of Energy and Inte-grated Charge Transfer Due to Partial Discharges(Co-rona)Using Bridge Techniques2.2 Special Technical Publications:Symposium on Corona,STP 198,ASTM,19562Corona Measurement and Interpretation,EngineeringDielectrics,Vol 1,STP 669,ASTM,197922.3 International Electrotechnical Commission(IEC)Docu-ments:IEC Publication 60343 Recommended Test Methods for De-termining the Relative Resistance of Insulating Materialsto Breakdown by Surface Discharges32.4 Institute of Electrical and Electronic Engineers(IEEE)Document:IEEE 930-1987 Guide for the Statistical Analysis of Electri-cal Insulation Voltage Endurance Data43.Terminology3.1 DefinitionsFor definitions of other terms used in thisstandard,refer to Terminology D1711 and Test Method D1868.3.2 Definitions of Terms Specific to This Standard:3.2.1 surface corona,ncorona that exists in the electri-cally stressed gas where electrodes are near insulation surfaces.3.2.2 threshold voltagethat voltage below which failurewill not occur under the test conditions irrespective of theduration of the test.3.2.3 voltage endurance,nthe time that an insulatingmaterial can withstand a prolonged alternating voltage stressunder the action of surface corona.3.2.4 voltage stress-time curve,na plot of the logarithm ofthe mean or median time to failure of a material against voltagestress(or the logarithm of voltage stress)for a particular set oftest conditions.3.2.4.1 DiscussionThe plot is the quantitative depiction ofthe voltage stress endurance over a range of voltage stress forthe conditions of test,and for the thickness tested.The curvesof a material obtained at two thicknesses are different.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 1964.Last previous edition approved in 2008 as D2275 01(2008)1.DOI:10.1520/D2275-14.2For 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 American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4Available from Institute of Electrical and Electronics Engineers,Inc.(IEEE),445 Hoes Ln.,P.O.Box 1331,Piscataway,NJ 08854-1331,http:/www.ieee.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.5 volt-time curve,na plot of the logarithm of the meanor median time to failure of a material against voltage(or thelogarithm of voltage)for a particular set of test conditions.3.2.5.1 DiscussionThe plot is the quanti