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Question
. f( v/ C6 e1 i' M/ F1) In case of components mounted on a printed wiring board (PWB) and placed across
3 N* o6 q0 B7 W' x' K8 ^(bridging) insulating distances on the PWB (e.g. providing basic or even reinforced insulation),- Q; S. d/ w; |3 a. ~
how to deal with the different distance requirements for distances on the printed wiring
6 z0 X7 f% m& R8 v& I \material and for distances on other plastics e.g. the housing material of the component
; K9 U; z9 N! m; U% C" i, _5 Z(depending on the applicable material group)?
; H: g7 K8 K9 V) Q4 J/ N2) In case of components mounted on a printed wiring board (PWB) and placed across' d/ r! d" X9 n1 R. X8 K7 V. O v
insulating distances on the PWB (e.g. providing basic or even reinforced insulation), how to4 e6 ]9 J5 _1 H! q; f" b% l" U: v
deal with the different distance requirements, if the material group for PWB and for the
5 T4 M! k6 o, S& y: o8 Dcomponents placed on it is not the same (e.g. PWB of material group I and relay base of
; O+ [6 B! J: c Tmaterial group IIIa)?
5 \% M' l- {; v6 ~! UDecision
! F) W" x3 r, \3 N a# K) x2 C1) The defined reduced values for the required creepage distances relevant to printed wiring
, [. W7 ?, w: I0 _! a/ Lmaterial in micro-environment of pollution degrees 1 and 2 may only be applied when there. T0 \5 l- y9 s- w* W9 @8 E
are no components bridging the investigated insulation. If components are bridging insulating
& }; w8 f3 X5 H7 R- c$ y8 edistances on the PWB, the creepage distance requirements relating to the (component)
+ e: ^* w% U) ~8 [! rmaterial representing the worst case has to be applied for the PWB also.$ U2 }+ ~6 N% h1 J5 Y7 P- l0 w7 m7 f
2) In case of different material groups for the PWB and the components, again the requirement5 d6 `& l; p5 S
relating to the material representing the worst case has to be used.
' J& ?1 T/ ~- E" `+ R; TRemark: A component is considered to bridge insulation on the PWB, if the surface of the7 J: C3 \3 y3 R, Y- D" }( p
component is located at a distance less than the value “X” (e.g. according to IEC 60664 series)! f( h7 \0 v) s, l. s/ J% f
from the isolating PWB surface. See also enclosed drawing.5 y& ~0 J0 X) [9 |3 O1 b$ o
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