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各位XDJM,谁做过UL的测试?4 Z& R3 }7 F% Q' |
有些关于UL867的问题请教各位:* o/ k+ a" l1 D* w- h8 A
44.2 Shorted trace test
! L- b' q k' h8 Q' o44.2.1 Printed-wiring board traces mentioned in 44.1.1 are to be tested as described in 44.2.2 – 44.2.4.
9 c( J" K! v; UAs a result of the testing:
5 c3 C4 p% h3 ja) The overcurrent protection associated with the branch circuit to the unit shall not open,
2 W' i$ U2 L$ @) l$ V, u- db) The ground circuit fuse shall not open,
" S! D9 V* T# Ec) A wire or a printed-wiring board trace shall not open, and
9 X+ }) f& H' x4 {d) The device shall emit no flame or molten metal.- S, x: I" d I0 z' D, \# i: Z! O r
# v8 {2 [* C- U( q8 |其实a)这条我很难理解:; @' L0 g2 G2 v* e- l/ \: N
分支电路的过电流保护装置不能开路,' q% u: k" X7 `+ a. _
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。
+ y6 F" U5 a& m+ X+ R各位觉得我这么理解对么?; o& D/ O4 m( u- c6 E+ E2 ~
如果不对,欢迎指正。- c, e7 J" F" C+ i1 t7 x/ s" {) r
谢谢。 |
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