关于爬电距离和空气间隙的标准

关于爬电距离和空气间隙的标准第一页，共三十六页。Minimumclearance(Table2)RatedimpulsevoltageVMinimumclearancemm3300.55000.58000.515000.525001.540003.060005.580008.0100011.0第二页，共三十六页。HowtofindtheminimumclearanceHouseholdapplianceareinovervoltagecategoryIISelecttheratedvoltageUsingthetable1tofindouttheratedimpulsevoltageAccordingtotable2,theminimumclearancecouldbefoundbyratedimpulsevoltageTheclearancesoffourinsulationtypes:BasicinsulationSupplementaryinsulationReinforcedinsulationFunctionalinsulation第三页，共三十六页。TheclearanceofbasicinsulationExample1 :WaterkettleRating :220–240V50Hz2500–3000WRatedvoltageVRatedimpulsevoltage(V)OvervoltagecategoryIIIIII<=50330500800>150and<=15080015002500>150and<=300150025004000220–240VUsingcategoryIITheratedimpulsevoltagewas2500V第四页，共三十六页。29.1.1clearancesofbasicinsulationRatedimpulsevoltageVMinimumclearancemm3300.55000.58000.515000.525001.540003.060005.580008.0100011.0Theminimumclearancesofbasicinsulationwas1.5mm第五页，共三十六页。Specialcomponentsforbasicinsulation

Theterminalsoftubularsheathedheatingelementscounted1mm,ifthemicroenvironmentispollutiondegree1.>1mmTubularsheathedheatingelementPollutiondegree1第六页，共三十六页。29.1.2clearanceofsupplementinsulationTheminimumclearanceissameasthebasicinsulationThedistancebetweenenclosureandinternalwire第七页，共三十六页。29.1.3clearanceofreinforcedinsulationThereinforcedinsulationusingthenextstepforratedimpulsevoltage.Betweenterminalandplasticenclosure第八页，共三十六页。29.1.4clearanceoffunctionalinsulation

BetweenterminalsThefunctionalinsulationisbetweenlivepartsofdifferentpotential第九页，共三十六页。PTCHeatingelementHairstraighterPTCheaterHairstraighterassembly第十页，共三十六页。DifferenttypesofPTCHeatingelements第十一页，共三十六页。InternalconstructionofPTCheatingelementTheclearancebetweensurfacesofPTCheatingelementsmaybereducedto1mmTheclearance>=1mmKaptonfilmPTCheatingplateElectrodeplate第十二页，共三十六页。29.2creepagedistancesStep1(Tofindoutthepollutiondegree)Pollutiondegree2appliesunlessPrecautionshavebeentakentoprotecttheinsulation,inwhichcasepollution1appliesTheinsulationissubjectedtoconductivepollution,inwhichcasepollutiondegree3appliesNote:Thepollutiondegreeshouldneedrefertopart2.第十三页，共三十六页。StandardPollutiondegree60335–2–3II60335–2–9III60335–2–14III60335–2–15III60335–2–23II60335–2–80IIIPollutiondegreeclassification第十四页，共三十六页。Trackingindex(CTI)valuesMaterialgroupI:600<=CTIMaterialgroupII:400<=CTIMaterialgroupIIIa:175<=CTI<400MaterialgroupIIIb:100<=CTI<175Step2(Tofindoutthematerialgroup)

Trackingindextester第十五页，共三十六页。Trackingindex(CTI)values第十六页，共三十六页。MinimumcreepagedistancesforbasicinsulationWorkingvoltageVCreepagedistancemmPollutiondegree123MaterialgroupMaterialgroupIIIIIIa/bIIIIIIa/b<=500.20.60.91.21.51.71.9ª>50and<=1250.30.81.11.51.92.12.4>125and<=2501.61.31.82.53.23.64.0>250and<=4001.02.02.84.05.05.66.3>400and<=5001.32.53.65.06.37.18.0>500and<=8001.83.24.56.38.09.010.0第十七页，共三十六页。ThecreepageofbasicinsulationExample1:WaterkettleRating:220–240V50Hz2500–3000WPollutiondegree3(refertostandard60335–2–15)Themicroenvironmentispollutiondegree3iftheinsulationcanbe pollutedbycondensationfromsteamproducedduringnormaluseof appliance.AssumethematerialgroupisIII(thetightengrade)Workingvoltageisbetween>125and<=250第十八页，共三十六页。ThecreepageofbasicinsulationWorkingvoltageVCreepagedistancemmPollutiondegree123MaterialgroupMaterialgroupIIIIIIa/bIIIIIIa/b<=500.20.60.91.21.51.71.9ª>50and<=1250.30.81.11.51.92.12.4>125and<=2501.61.31.82.53.23.64.0>250and<=4001.02.02.84.05.05.66.3>400and<=5001.32.53.65.06.37.18.0>500and<=8001.83.24.56.38.09.010.0第十九页，共三十六页。WorkingvoltageVCreepagedistancemmPollutiondegree123MaterialgroupMaterialgroupIIIIIIa/bIIIIIIa/b<=500.20.60.81.11.41.61.8ª>50and<=1250.30.71.01.41.82.02.2>125and<=2500.41.01.42.02.52.83.2>250and<=4000.81.62.23.24.04.55.0>400and<=5001.02.02.84.05.05.66.3>500and<=8001.83.24.56.38.09.010.0Minimumcreepagedistancesforfunctionalinsulation第二十页，共三十六页。InsulationtypeDistanceBasicinsulation4Supplementaryinsulation4Reinforcedinsulation8Functionalinsulation3.2SummaryofMinimumcreepagedistances

第二十一页，共三十六页。29.2.1creepageforbasicinsulation

Lacqueredconductorsofwindings1.5mmCreepagedistanceofwindingneednotbegreaterthantheassociatedclearancespecifiedintable16第二十二页，共三十六页。

Asperclause29.2.2,thecreepagedistanceofsupplementaryinsulationshallnotlessthanand2.5mm.Theinternalwireofmicro-switchwasnotsecurelyfixedthatitwaspossibletobetouchedbytestfingerwith2Nforce.Thecreepagedistanceweremeasuredas0mmInternalwireshallbeaccess第二十三页，共三十六页。

Thecreepagedistancesofreinforcedinsulationshallnotlessthan8mm.Asresult,thecreepagedistancewasmeasured7.5mmbetweenleadsofneonlampandthelampcoverjoint.

LeadsofneonlampLensEnclosureLeonlampleads2mm3mm2.5mThecreepagedistances=2.5+2+3 =7.5mm第二十四页，共三十六页。

29.2.4creepagedistancesoffunctionalinsulationCreepagedistancebetweenMeasuredresultsLimitationSwitchterminals1.5mm2mm1.5mm第二十五页，共三十六页。DistancebetweenMeasuredresultsLimitationPCBBetweenPointAandBClearanceCreepageClearanceCreepage2.07mm2.75mm1.5mm2.0mm第二十六页，共三十六页。PCBTrackABBABA第二十七页，共三十六页。29.2.4creepagedistanceforfunctioninsulationCreepagedistancesmaybereducediftheappliancecomplieswithclause19withthefunctionalinsulationshort-circuited.Forexample:ElectroniccomponentElectroniccomponentThetransistorleads<limitationofcreepagedistance第二十八页，共三十六页。LivePartSupplementaryinsulation(1mm)Basicinsulation29.3.1Materialthicknessrequirementforsupplementaryinsulation(1)SupplementaryInsulation第二十九页，共三十六页。LivePartReinforcedinsulation(2mm)29.3.1Materialthicknessrequirementforreinforcedinsulation(1)ReinforcedInsulation第三十页，共三十六页。LivePart1stlayerinsulation2ndlayerinsulationEachofthelayersshou