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Question
2 q) b( A G) P- v1) In case of components mounted on a printed wiring board (PWB) and placed across
; x9 ?0 V# f8 R* S9 {(bridging) insulating distances on the PWB (e.g. providing basic or even reinforced insulation),) }$ N1 v+ s/ i6 e3 ?
how to deal with the different distance requirements for distances on the printed wiring, f" I, o) c4 Y1 y, y; f9 g0 U
material and for distances on other plastics e.g. the housing material of the component( }* ~0 k3 h6 e
(depending on the applicable material group)?! l+ W# T" K$ ^5 m. Y
2) In case of components mounted on a printed wiring board (PWB) and placed across* \( w) X* k+ R4 A+ m
insulating distances on the PWB (e.g. providing basic or even reinforced insulation), how to* E* i- p' Z9 e, d% b1 m$ [4 D3 n1 O
deal with the different distance requirements, if the material group for PWB and for the
( @; A- I i$ e5 ^' o' _0 u8 lcomponents placed on it is not the same (e.g. PWB of material group I and relay base of' r" |6 u v$ Z, s8 R$ D
material group IIIa)?
+ j( @- u& j$ B0 k# t \. K! kDecision
* m! ]* D6 @8 x4 M* ~3 Y1) The defined reduced values for the required creepage distances relevant to printed wiring5 Y& q& ~' u1 j d% o% Z
material in micro-environment of pollution degrees 1 and 2 may only be applied when there
; e1 k6 g2 t: E" J2 D5 ?. Nare no components bridging the investigated insulation. If components are bridging insulating
, Y% q9 ~* `7 m: l' X H1 ~distances on the PWB, the creepage distance requirements relating to the (component)3 A; c( F6 i5 h0 M
material representing the worst case has to be applied for the PWB also.
4 V r0 ~' b8 i5 S4 ^2) In case of different material groups for the PWB and the components, again the requirement
) }" Y6 q; z3 O8 E, n: Grelating to the material representing the worst case has to be used.
- i; v0 j9 Q+ Y+ TRemark: A component is considered to bridge insulation on the PWB, if the surface of the6 ]* E7 i9 A& F% ]
component is located at a distance less than the value “X” (e.g. according to IEC 60664 series)
4 z6 z- ]. d! c# J4 }from the isolating PWB surface. See also enclosed drawing.0 S* ]& t1 l4 M
0 W, a0 Y9 v% g' T4 G9 v& ]. n X0 i7 n8 D
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