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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.
, q% |3 O, f! Q% e1 n; m$ a; [1 K& ]4 K2. 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.! W, H( ^ _( |: s. V$ o, j! V
3. 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.* F# S% R; J6 |) S5 ^
4. 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 .
4 `9 a( L! p d$ z$ k0 U3 [: v% u5 x- U5. A creepage path is assumed not to exist if there is an air gap as defined in item 2 above exceeding 0,25 mm.
2 f! b) G' F; D+ z+ [. |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.
7 e6 ~- F: j Z" I6 R' L7. A computed creepage distance is never less than a measured clearance.8 A7 B" r; G. m9 k" b" n
8. 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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