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8 rules for creepage distance and clearance
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1. A groove may have parallel, converging or diverging sides.1 n [" {8 R- K% b0 ~. {9 [8 z
2. Any groove having diverging sides, a minimum width exceeding 0,25 mm, a depth exceeding 1,5 mm and a width at the bottom equal to or greater than 1 mm, is regarded as an air gap.
! i+ R8 G8 n w: X' I; J3. Any corner including an angle less than 80° is assumed to be bridged with an insulating link of 1 mm width (0,25 mm for dirt-free situations) moved into the most unfavourable position.
( X9 |$ Y0 m0 n; V8 H4. Where the distance across the top of a groove is 1 mm (0,25 mm for dirt-free situations) or more, no creepage distance exists across the air space .7 X+ [$ P) e! u1 K
5. A creepage path is assumed not to exist if there is an air gap as defined in item 2 above exceeding 0,25 mm.- q) w1 E1 E' r& F
6. Creepage distances and clearances measured between parts moving relative to each other are measured when these parts are in their most unfavourable stationary positions.
8 B8 Z/ c% |( ^" Y" M# F7. A computed creepage distance is never less than a measured clearance.
( D" n! A" y: F8. Any air gap less than 1 mm wide (0,25 mm for dirt-free situations) is ignored in computing the total clearance. |
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