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Question( G# G4 j% { C# R- H& p; @
1) In case of components mounted on a printed wiring board (PWB) and placed across
& b( `. t* _; w2 f(bridging) insulating distances on the PWB (e.g. providing basic or even reinforced insulation),
$ ?' ?% b; M* f/ Chow to deal with the different distance requirements for distances on the printed wiring
" ]& Y& T( _1 B* n9 ?! [) Qmaterial and for distances on other plastics e.g. the housing material of the component
2 j' h9 r J& W(depending on the applicable material group)?
3 m. z K m1 q. N- \2) In case of components mounted on a printed wiring board (PWB) and placed across: p3 q0 a( u/ F; B( I; A# `
insulating distances on the PWB (e.g. providing basic or even reinforced insulation), how to
& U0 U$ B7 n8 x+ ^" z) o7 Mdeal with the different distance requirements, if the material group for PWB and for the' O7 {8 \: |4 a6 U
components placed on it is not the same (e.g. PWB of material group I and relay base of/ @; a4 \. t) M4 Z" \% n; w
material group IIIa)?
& ~' O, q9 t- m. Z8 GDecision6 Q; |" J& w5 w& ~. p9 ?& }- \% `
1) The defined reduced values for the required creepage distances relevant to printed wiring. D! ~# j% Z% Y( `
material in micro-environment of pollution degrees 1 and 2 may only be applied when there
* }6 \5 F& {6 t. t1 V* a1 Aare no components bridging the investigated insulation. If components are bridging insulating
. H, ~( S w9 o" T3 Xdistances on the PWB, the creepage distance requirements relating to the (component)
5 c, ~. a! M# p v1 p9 B- Amaterial representing the worst case has to be applied for the PWB also.1 b+ w3 J4 x" _' i
2) In case of different material groups for the PWB and the components, again the requirement% C2 \# l* Y2 G: M
relating to the material representing the worst case has to be used.
" }, F. T, b. K, U4 h9 `. M5 r9 [5 VRemark: A component is considered to bridge insulation on the PWB, if the surface of the: C8 B& {& u0 i' v5 |5 |
component is located at a distance less than the value “X” (e.g. according to IEC 60664 series)
& R b) c, z- t$ @) c. Wfrom the isolating PWB surface. See also enclosed drawing.
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