DSH 2001
Question1) In case of components mounted on a printed wiring board (PWB) and placed across
(bridging) insulating distances on the PWB (e.g. providing basic or even reinforced insulation),
how to deal with the different distance requirements for distances on the printed wiring
material and for distances on other plastics e.g. the housing material of the component
(depending on the applicable material group)?
2) In case of components mounted on a printed wiring board (PWB) and placed across
insulating distances on the PWB (e.g. providing basic or even reinforced insulation), how to
deal with the different distance requirements, if the material group for PWB and for the
components placed on it is not the same (e.g. PWB of material group I and relay base of
material group IIIa)?
Decision
1) The defined reduced values for the required creepage distances relevant to printed wiring
material in micro-environment of pollution degrees 1 and 2 may only be applied when there
are no components bridging the investigated insulation. If components are bridging insulating
distances on the PWB, the creepage distance requirements relating to the (component)
material representing the worst case has to be applied for the PWB also.
2) In case of different material groups for the PWB and the components, again the requirement
relating to the material representing the worst case has to be used.
Remark: A component is considered to bridge insulation on the PWB, if the surface of the
component is located at a distance less than the value “X” (e.g. according to IEC 60664 series)
from the isolating PWB surface. See also enclosed drawing.
DSH 2001附件
页:
[1]
