Designation:D3251−19StandardTestMethodforThermalEnduranceCharacteristicsofElectricalInsulatingVarnishesAppliedOverFilm-InsulatedMagnetWire1ThisstandardisissuedunderthefixeddesignationD3251;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofthethermalendurancecharacteristicsofelectricalinsulatingvarnishesandfilm-insulatedmagnetwireincombination.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.NOTE1—ThistestmethodisequivalenttoIEC60172.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D115TestMethodsforTestingSolventContainingVar-nishesUsedforElectricalInsulationD1711TerminologyRelatingtoElectricalInsulationD2307TestMethodforThermalEnduranceofFilm-InsulatedRoundMagnetWire2.2IECStandard:IEC60172TestProcedureforthedeterminationofthetemperatureindexofenameledwindingwires33.Terminology3.1Definitions:3.1.1FordefinitionsoftermsusedinthistestmethodrefertoTerminologyD1711.4.SummaryofTestMethod4.1Avarnishisappliedtotwistedpairsoffilm-insulatedmagnetwireandexposedtoelevatedtemperatures.Lifetestresultsarecomparedtothoseofunvarnishedtwistedpairs.5.SignificanceandUse5.1Differentcombinationsofvarnishesandfilm-insulatedmagnetwirebehavedifferentlywhenexp...
