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各位XDJM,谁做过UL的测试?! l A% r- `6 v, c
有些关于UL867的问题请教各位:
* J6 a0 K W8 M4 r8 _9 u' x: D44.2 Shorted trace test
* d4 h7 J7 W2 p5 d44.2.1 Printed-wiring board traces mentioned in 44.1.1 are to be tested as described in 44.2.2 – 44.2.4.# |5 p* g+ K) Z8 Z4 i6 v
As a result of the testing:9 b5 w0 _' m1 d$ V4 F3 v/ G6 H
a) The overcurrent protection associated with the branch circuit to the unit shall not open,1 O% C& x6 q: E: I
b) The ground circuit fuse shall not open,
# h+ u, w S( G+ B0 Tc) A wire or a printed-wiring board trace shall not open, and5 k4 @6 r( Y: B0 ?1 q
d) The device shall emit no flame or molten metal.1 A- D2 j4 E9 O. x& L4 D
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其实a)这条我很难理解:# f* E5 M& I' m( z3 m8 T3 y$ @
分支电路的过电流保护装置不能开路,
% O- `" F* q; }; M3 h5 \8 ^这点是为什么呢?如果过流保护装置形成开路的话,那整个电路肯定就是安全的,不可能存在任何危险?标准要求不能形成开路,那要这个过流保护装置就没有任何意义了。2 B$ ?: I( B! E% @
各位觉得我这么理解对么?& u( ~9 H% f+ m: l: g1 i
如果不对,欢迎指正。
% X. D. P+ i, x% u+ w谢谢。 |
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