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Question" i: W6 A4 r$ F9 p' C
1) In case of components mounted on a printed wiring board (PWB) and placed across
0 Q( W: f7 C: H(bridging) insulating distances on the PWB (e.g. providing basic or even reinforced insulation),+ k2 y/ P& X5 h6 {6 g2 c e
how to deal with the different distance requirements for distances on the printed wiring9 a$ g1 q3 l% I0 I
material and for distances on other plastics e.g. the housing material of the component
1 p$ g. B- w' N$ |, ~(depending on the applicable material group)?0 {- \0 ^2 S1 Q
2) In case of components mounted on a printed wiring board (PWB) and placed across7 S4 W+ x. |; ^( Y
insulating distances on the PWB (e.g. providing basic or even reinforced insulation), how to4 \6 t' K9 C E/ W8 d% K+ Q" L
deal with the different distance requirements, if the material group for PWB and for the" y/ _) |4 e/ y3 j0 l1 [6 U9 J' {+ ^! {
components placed on it is not the same (e.g. PWB of material group I and relay base of
. C) P5 F8 [, O; N; o9 Qmaterial group IIIa)?
5 D$ ?: `+ r: q- x/ x8 \" H9 dDecision
8 A1 j+ S* Q, h j9 c1) The defined reduced values for the required creepage distances relevant to printed wiring
* t3 `. W l% E6 e+ C3 lmaterial in micro-environment of pollution degrees 1 and 2 may only be applied when there
9 T7 N: ?/ a1 Kare no components bridging the investigated insulation. If components are bridging insulating
, u f u- A s8 s/ h, |distances on the PWB, the creepage distance requirements relating to the (component)& L% {( ~3 }' `5 f! r( R. u$ Z6 I7 e
material representing the worst case has to be applied for the PWB also.
1 m/ P! k+ N- Y, b7 G4 m7 K2 I2) In case of different material groups for the PWB and the components, again the requirement
+ p4 A( E+ Q% j: Srelating to the material representing the worst case has to be used.
; K2 z! ?8 a; ORemark: A component is considered to bridge insulation on the PWB, if the surface of the5 x) B, k) `' @* d; {' x8 p
component is located at a distance less than the value “X” (e.g. according to IEC 60664 series)" _ B/ r/ X3 h
from the isolating PWB surface. See also enclosed drawing.: }3 O4 B; s2 X, ]2 z( I/ A
' s* _; A$ Y- m9 [+ b
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