EN60335关于爬电距离和空气间隙的标准

1、Rated voltageVRated impulse voltageVOvervoltage categoryIIIIII50 and 150 and =300150025004000Clause 29 Clearances, Creepage distances and solid insulation电气间隙、爬电距离和绝缘穿通距离 (Table 1)Minimum clearance (Table 2)Rated impulse voltageVMinimum clearancemm3300.55000.58000.515000.525001.540003.060005.580008.

2、0100011.0How to find the minimum clearance Household appliance are in overvoltage category II Select the rated voltage Using the table 1 to find out the rated impulse voltage According to table 2, the minimum clearance could be found by rated impulse voltageThe clearances of four insulation types:1.

3、Basic insulation2.Supplementary insulation3.Reinforced insulation4.Functional insulationThe clearance of basic insulationExample 1: Water kettleRating : 220 240V 50Hz 2500 3000WRated voltageVRated impulse voltage (V)Overvoltage categoryIIIIII150 and 150 and 1mmTubular sheathed heating elementPolluti

4、on degree 129.1.2 clearance of supplement insulationThe minimum clearance is same as the basic insulationThe distance between enclosure and internal wire29.1.3 clearance of reinforced insulationThe reinforced insulation using the next step for rated impulse voltage. Between terminal and plastic encl

5、osure29.1.4 clearance of functional insulation Between terminalsThe functional insulation is between live parts of different potentialPTC Heating elementHair straighterPTC heaterHair straighter assemblyDifferent types of PTC Heating elementsInternal construction of PTC heating elementThe clearance b

6、etween surfaces of PTC heating elements may be reduced to 1mmThe clearance =1mmKapton filmPTC heating plateElectrode plate29.2 creepage distancesStep 1 (To find out the pollution degree)Pollution degree 2 applies unlessPrecautions have been taken to protect the insulation, in which case pollution 1

7、appliesThe insulation is subjected to conductive pollution, in which case pollution degree 3 appliesNote: The pollution degree should need refer to part 2. StandardPollution degree60335 2 3II60335 2 9III60335 2 14III60335 2 15 III60335 2 23 II60335 2 80 IIIPollution degree classificationTracking ind

8、ex (CTI) valuesMaterial group I: 600=CTIMaterial group II: 400=CTIMaterial group III a: 175 =CTI 400Material group III b: 100 =CTI175Step 2 (To find out the material group)Tracking index testerTracking index (CTI) valuesMinimum creepage distances for basic insulationWorking voltageVCreepage distance

9、 mmPollution degree123Material groupMaterial groupIIIIII a/bIIIIII a/b50 and 125 and 250 and 400 and 500 and 125 and =250The creepage of basic insulationWorking voltageVCreepage distance mmPollution degree123Material groupMaterial groupIIIIII a/bIIIIII a/b50 and 125 and 250 and 400 and 500 and = 800

10、1.83.24.56.38.09.010.0Working voltageVCreepage distance mmPollution degree123Material groupMaterial groupIIIIII a/bIIIIII a/b50 and 125 and 250 and 400 and 500 and = 8001.83.24.56.38.09.010.0Minimum creepage distances for functional insulationInsulation typeDistanceBasic insulation4Supplementary ins

11、ulation4Reinforced insulation8Functional insulation3.2Summary of Minimum creepage distances 29.2.1 creepage for basic insulationLacquered conductors of windings1.5mmCreepage distance of winding need not be greater than the associated clearance specified in table 16 Clause 29.2.2As per clause 29.2.2,

12、 the creepage distance of supplementary insulation shall not less than and 2.5mm.The internal wire of micro-switch was not securely fixed that it was possible to be touched by test finger with 2N force. The creepage distance were measured as 0mmInternal wire shall be accessClause 29.2.3The creepage

13、distances of reinforced insulation shall not less than 8mm.As result, the creepage distance was measured 7.5mm between leads of neon lamp and the lamp cover joint. Leads of neon lampLensEnclosureLeon lamp leads2mm3mm2.5mThe creepage distances = 2.5+2+3 = 7.5mm29.2.4 creepage distances of functional

14、insulationCreepage distance betweenMeasured resultsLimitationSwitch terminals1.5mm2mm1.5mmClause 29.2.4Distance betweenMeasured resultsLimitationPCBBetween Point A and BClearanceCreepageClearanceCreepage2.07mm2.75mm1.5mm2.0mmPCB TrackA BB AB A29.2.4 creepage distance for function insulationCreepage

15、distances may be reduced if the appliance complies with clause 19 with the functional insulation short-circuited. For example: Electronic component Electronic componentThe transistor leads limitation of creepage distance LivePartSupplementaryinsulation(1mm)Basicinsulation29.3.1 Material thickness re

16、quirement for supplementary insulation (1)SupplementaryInsulationLivePartReinforced insulation (2mm)29.3.1 Material thickness requirement for reinforced insulation (1)ReinforcedInsulationLivePart1st layer insulation2nd layer insulationEach of the layers should withstands the electric strength test for supplementary insulation 29.3.2 Material requirement for supplementary insulation (2)Basic insulation29.3.2 Material requirement for reinforced insulation (2)LivePart1stlayerinsulation2ndlayerinsulation3rdlayerinsulationAnytwolayerstogethershouldwithstandstheelectricstrengthtestforreinforcedi