关于爬电距离和空气间隙的标准演示幻灯片

,Clause29Clearances,Creepagedistancesandsolidinsulation爬电距离、电气间隙和绝缘穿通距离(Table1),1,2020/5/5,Minimumclearance(Table2),2,2020/5/5,Howtofindtheminimumclearance,HouseholdapplianceareinovervoltagecategoryIISelecttheratedvoltageUsingthetable1tofindouttheratedimpulsevoltageAccordingtotable2,theminimumclearancecouldbefoundbyratedimpulsevoltage,Theclearancesoffourinsulationtypes:BasicinsulationSupplementaryinsulationReinforcedinsulationFunctionalinsulation,3,2020/5/5,Theclearanceofbasicinsulation,Example1:WaterkettleRating:220240V50Hz25003000W,220240V,UsingcategoryII,Theratedimpulsevoltagewas2500V,4,2020/5/5,29.1.1clearancesofbasicinsulation,Theminimumclearancesofbasicinsulationwas1.5mm,5,2020/5/5,Specialcomponentsforbasicinsulation,Theterminalsoftubularsheathedheatingelementscounted1mm,ifthemicroenvironmentispollutiondegree1.,1mm,Tubularsheathedheatingelement,Pollutiondegree1,6,2020/5/5,29.1.2clearanceofsupplementinsulation,Theminimumclearanceissameasthebasicinsulation,Thedistancebetweenenclosureandinternalwire,7,2020/5/5,29.1.3clearanceofreinforcedinsulation,Thereinforcedinsulationusingthenextstepforratedimpulsevoltage.,Betweenterminalandplasticenclosure,8,2020/5/5,29.1.4clearanceoffunctionalinsulation,Betweenterminals,Thefunctionalinsulationisbetweenlivepartsofdifferentpotential,9,2020/5/5,PTCHeatingelement,Hairstraighter,PTCheater,Hairstraighterassembly,10,2020/5/5,DifferenttypesofPTCHeatingelements,11,2020/5/5,InternalconstructionofPTCheatingelement,TheclearancebetweensurfacesofPTCheatingelementsmaybereducedto1mm,Theclearance=1mm,Kaptonfilm,PTCheatingplate,Electrodeplate,12,2020/5/5,29.2creepagedistances,Step1(Tofindoutthepollutiondegree)Pollutiondegree2appliesunlessPrecautionshavebeentakentoprotecttheinsulation,inwhichcasepollution1appliesTheinsulationissubjectedtoconductivepollution,inwhichcasepollutiondegree3appliesNote:Thepollutiondegreeshouldneedrefertopart2.,13,2020/5/5,Pollutiondegreeclassification,14,2020/5/5,Trackingindex(CTI)valuesMaterialgroupI:600=CTIMaterialgroupII:400=CTIMaterialgroupIIIa:175=CTI400MaterialgroupIIIb:100=CTI125and=250,18,2020/5/5,Thecreepageofbasicinsulation,19,2020/5/5,Minimumcreepagedistancesforfunctionalinsulation,20,2020/5/5,SummaryofMinimumcreepagedistances,21,2020/5/5,29.2.1creepageforbasicinsulationLacqueredconductorsofwindings,1.5mm,Creepagedistanceofwindingneednotbegreaterthantheassociatedclearancespecifiedintable16,22,2020/5/5,Clause29.2.2,Asperclause29.2.2,thecreepagedistanceofsupplementaryinsulationshallnotlessthanand2.5mm.Theinternalwireofmicro-switchwasnotsecurelyfixedthatitwaspossibletobetouchedbytestfingerwith2Nforce.Thecreepagedistanceweremeasuredas0mm,Internalwireshallbeaccess,23,2020/5/5,Clause29.2.3,Thecreepagedistancesofreinforcedinsulationshallnotlessthan8mm.Asresult,thecreepagedistancewasmeasured7.5mmbetweenleadsofneonlampandthelampcoverjoint.,Leadsofneonlamp,Lens,Enclosure,Leonlampleads,2mm,3mm,2.5m,Thecreepagedistances=2.5+2+3=7.5mm,24,2020/5/5,29.2.4creepagedistancesoffunctionalinsulation,1.5mm,25,2020/5/5,Clause29.2.4,26,2020/5/5,PCBTrack,AB,BA,BA,27,2020/5/5,29.2.4creepagedistanceforfunctioninsulation,Creepagedistancesmaybereducediftheappliancecomplieswithclause19withthefunctionalinsulationshort-circuited.Forexample:Electroniccomponent,Electroniccomponent,Thetransistorleadslimitationofcreepagedistance,28,2020/5/5,LivePart,Supplementaryinsulation(1mm),Basicinsulation,29.3.1Materialthicknessrequirementforsupplementaryinsulation(1),SupplementaryInsulation,29,2020/5/5,LivePart,Reinforcedinsulation(2mm),29.3.1Materialthicknessrequirementforreinforcedinsulation(1),ReinforcedInsulation,30,2020/5/5,LivePart,1stlayerinsulation,2ndlayerinsulation,Eachofthelayersshouldwithstandstheelectricstrengthtestforsupplementaryinsulation,29.3.2Materialrequirementforsupplementaryinsulation(2),Basicinsulation,31,2020/5/5,29.3.2Materialrequirementforreinforcedinsulation(2),LivePart,1stlayerinsulation,2ndlayerinsulation,3rdlayerinsulation,Anytwolayerstogethershouldwithstandstheelectricstrengthtestforreinforcedinsulation,32,2020/5/5,=1mm,Case2,Clearance,Creepagedistance,34,2020/5/5,1mm,Case3,Clearance,Creepage