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各位XDJM,谁做过UL的测试?
: G% x; Z$ b; b/ K7 C# ~有些关于UL867的问题请教各位:5 r2 E- [- `' J' v
44.2 Shorted trace test
* W8 H/ \2 L* |' d# C6 H- ]44.2.1 Printed-wiring board traces mentioned in 44.1.1 are to be tested as described in 44.2.2 – 44.2.4." h# N6 w4 ?7 W. ^; X/ N
As a result of the testing:
. M( P' E3 v) U( ^* Y9 N/ j5 d: x6 ~% E ^a) The overcurrent protection associated with the branch circuit to the unit shall not open,9 I1 [$ b& w8 Y: B' G" m2 X6 G
b) The ground circuit fuse shall not open,1 ?/ I' }) U2 V( O8 x
c) A wire or a printed-wiring board trace shall not open, and
+ D: N! V* _5 Q, S, C1 w3 gd) The device shall emit no flame or molten metal.4 Y$ _4 R$ a4 j, W
. J4 U/ I# b% n- m其实a)这条我很难理解:
+ v/ M' J, `0 C5 d* r4 G9 F5 W3 z4 f- b分支电路的过电流保护装置不能开路,6 K, k$ j) M# l2 h b$ X
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。% Q% o3 r# B# {% D% }: d
各位觉得我这么理解对么?
[" g: b+ n+ Z D* a* p0 m$ [% E如果不对,欢迎指正。3 O E' N1 C8 D; S
谢谢。 |
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