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我搞了几年安规,主要是IEC和EN的标准,对这个概念一直没弄太明白,上次有机会问了一下公司总部的一个专家,听了也还是没弄明白。请大家解惑。" E# p/ k# M# Y/ r+ [
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同行们一般这样处理案子,比如遇到一个电源,判断其输出端子是否为hazardous live parts. 要求满足两个条件(如果这两种条件都存在,则要同时满足):2 C8 q! ^1 b( X+ z( w! B
一)是要根据不同标准判断其是否符合SELV,比如
% a, u' u- H# l+ R2 p在IEC 60335-1里,是不大于42.4V a.c. (peak)或42.4V d.c.;
& O( W4 N& X- u+ e" ]% x在IEC 60065里,是不大于 & B3 b7 N2 `/ i- u# _& P! \( K
-35V (peak) 60V d.c. ;
& t# k, m. S6 \6 `8 `0 C# M -对专业设备的音频信号,120V r.m.s.8 v8 a& r) Q/ K' H/ |
-对非专业设备的音频信号,71V r.m.s.
) X6 \9 q, U# p" h0 d& B: GIEC 61558-1里,是不大于 35V a.c. (peak) 或者说60V d.c.;
/ {0 {' B \* d5 y5 M% J6 m在IEC 60950-1里,是不大于 42.4V a.c. (peak) 或60V d.c.. s( L' @( p8 J4 B2 {
二)是如果在初次级有保护性阻抗(protective impedance),则要求4 [2 F4 [2 A0 X) ]. v+ C" E `
在IEC 60335-1里: if protective impedance is used, the current between the part and the supply source shall not exceed 2mA for d.c., its peak value shall not exceed 0,7maA for a.c. and
$ Z% A# G! T3 L9 i# \% G' }+ o-for voltages having a peak value over 42,4V up to and including 450V, the capacitance shall not exceed 0,1uF,
8 u4 U' h I; r# G- for voltages having a peak value over 450V up to and including 15kV, the discharge shall not exceed 45 micro V,6 a+ x* z+ i0 R
-for voltages having a peak value over 15 kV, the energy in the discharge shall not exceed 350mJ. |
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