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各位XDJM,谁做过UL的测试?6 g1 e3 m4 I Y( t$ e8 a
有些关于UL867的问题请教各位:& n5 v+ e1 Q. | C
44.2 Shorted trace test' C/ b1 u$ N8 B! w' T% a
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.
# q( N: Z) e! ^0 k' G& lAs a result of the testing:; D1 U9 {+ W2 }4 ~0 U% |% A
a) The overcurrent protection associated with the branch circuit to the unit shall not open,& X) Y! J* V' D1 e; [( p, o
b) The ground circuit fuse shall not open,
1 H' g0 k. Q" Qc) A wire or a printed-wiring board trace shall not open, and; v* A& ^% h% x! q2 z
d) The device shall emit no flame or molten metal.
: K7 _) c1 k4 f, G* G
8 q6 q- {" X, S S: F, N其实a)这条我很难理解:2 i. A; O: @; t% Z T0 e
分支电路的过电流保护装置不能开路,
! {" E2 v- o; @. H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。
4 ?/ H& l3 _% Z. d! e4 g各位觉得我这么理解对么?" `/ w6 X2 y; x3 E
如果不对,欢迎指正。6 w% n( i& z' R a1 A! ~8 B
谢谢。 |
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