关于爬电距离和空气间隙的标准.ppt

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1、RatedvoltageVRatedimpulsevoltageVOvervoltagecategoryIIIIII<=50330500800>50and<=15080015002500>150and<=300150025004000Clause29Clearances,Creepagedistancesandsolidinsulation爬电距离、电气间隙和绝缘穿通距离(Table1)Minimumclearance(Table2)RatedimpulsevoltageVMinimumclearancemm3300.55000.580

2、00.515000.525001.540003.060005.580008.0100011.0HowtofindtheminimumclearanceHouseholdapplianceareinovervoltagecategoryIISelecttheratedvoltageUsingthetable1tofindouttheratedimpulsevoltageAccordingtotable2,theminimumclearancecouldbefoundbyratedimpulsevoltageTheclearancesoff

3、ourinsulationtypes:BasicinsulationSupplementaryinsulationReinforcedinsulationFunctionalinsulationTheclearanceofbasicinsulationExample1:WaterkettleRating:220–240V50Hz2500–3000WRatedvoltageVRatedimpulsevoltage(V)OvervoltagecategoryIIIIII<=50330500800>150and<=15080015002500

4、>150and<=300150025004000220–240VUsingcategoryIITheratedimpulsevoltagewas2500V29.1.1clearancesofbasicinsulationRatedimpulsevoltageVMinimumclearancemm3300.55000.58000.515000.525001.540003.060005.580008.0100011.0Theminimumclearancesofbasicinsulationwas1.5mmSpecialcomponents

5、forbasicinsulationTheterminalsoftubularsheathedheatingelementscounted1mm,ifthemicroenvironmentispollutiondegree1.>1mmTubularsheathedheatingelementPollutiondegree129.1.2clearanceofsupplementinsulationTheminimumclearanceissameasthebasicinsulationThedistancebetweenenclosure

6、andinternalwire29.1.3clearanceofreinforcedinsulationThereinforcedinsulationusingthenextstepforratedimpulsevoltage.Betweenterminalandplasticenclosure29.1.4clearanceoffunctionalinsulationBetweenterminalsThefunctionalinsulationisbetweenlivepartsofdifferentpotentialPTCHeatin

7、gelementHairstraighterPTCheaterHairstraighterassemblyDifferenttypesofPTCHeatingelementsInternalconstructionofPTCheatingelementTheclearancebetweensurfacesofPTCheatingelementsmaybereducedto1mmTheclearance>=1mmKaptonfilmPTCheatingplateElectrodeplate29.2creepagedistancesStep

8、1(Tofindoutthepollutiondegree)Pollutiondegree2appliesunlessPrecautionshavebeentakentoprotecttheinsulati