Designation:D877/D877M−13StandardTestMethodforDielectricBreakdownVoltageofInsulatingLiquidsUsingDiskElectrodes1ThisstandardisissuedunderthefixeddesignationD877/D877M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethoddescribestwoprocedures,AandB,fordeterminingtheelectricalbreakdownvoltageofinsulatingliquidspecimens.Thebreakdowntestusesacvoltageinthepower-frequencyrangefrom45to65Hz.1.2Thistestmethodisusedtojudgeifthediskelectrodebreakdownvoltagerequirementsaremetforinsulatingliquids,asdeliveredfromthemanufacturer,thathaveneverbeenfilteredordried.SeeSpecificationD3487,SpecificationD4652,SpecificationD6871andGuideD5222forthemini-mumspecifiedelectricalbreakdown.Thistestmethodshouldbeusedasrecommendedbyprofessionalorganizationstan-dardssuchasIEEEC57.106.1.3LimitationsoftheProcedures:1.3.1Thesensitivityofthistestmethodtothegeneralpopulationofcontaminantspresentinaliquidsamplede-creasesasappliedtestvoltagesusedinthistestmethodbecomegreaterthanapproximately25kVrms.1.3.2Iftheconcentrationofwaterinthesampleatroomtemperatureislessthan60%ofsaturation,thesensitivityofthistestmethodtothepresenceofwaterisdecreased.ForfurtherinformationrefertoRR:D27-1006.21.3.3Thesuitabilityforthistestmethodhasnotbeendeterminedforaliquid’sviscosityhigherthan900cStat40°C.1.4ProcedureApplications1.4.1ProcedureA:1.4.1.1ProcedureAisusedtodeterminethebreakdownvoltageofliquidsinwhichanyinsolublebreakdownproductseasilysettleduringtheintervalbetweentherequiredrepeatedbreakdowntests.Theseliquidsincludepetroleumoils,hydrocarbons,naturalandsyntheticesters,andaskarels(PCB)usedasinsulatingandcoolingliquidsintransformers,cables,andsimilarapparatus.1.4.1.2ProcedureAmaybeusedtoobtainthedielectricbreakdownofsilic...
