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在UL线路板说明(见下网址)
7 b4 T& c3 O! W0 s0 i3 Lhttp://database.ul.com/cgi-bin/X ... 4637&sequence=11 r2 t- ?( t/ F# P5 X" E
看到:
% V$ H6 N+ H2 w9. Voltage Rating — No voltage rating is assigned. The suitability of the base material as insulation between live-metal parts and dead-metal parts shall be determined in the end product.
- n9 J% o2 U3 D) v5 R/ G10. Minimum Spacing — Minimum required spacing between conductors of different potential and between these conductors and dead-metal parts. Cupping, twisting, bowing and/or warping of the board has not been investigated. % U/ a6 C* U& ` H) f0 ^+ C
11. Minimum Dielectric Thickness — Minimum required dielectric/insulation thickness (distance through) between conductor layers has not been investigated regarding dielectric strength requirements in the end-product design.
W' |# o+ d1 s$ j4 g/ h可见,有关防电击的要求,如额定电压、安全距离、最小的夹层绝缘厚度要求,并未在线路板认证中进行评估。' X' F4 a7 i! S. G9 W
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UL接受非隔离电源,很可能是因为额定电压低(只有120V)。我记得UL的不接地灯具也只打1250V的耐压。 |
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