|
The fuse-link is short-circuited during the test and the current passing through both the fuselink
) @& `/ j/ T+ ^. e! c$ Wand the short-circuit link under the relevant fault condition, is measured:
6 z/ y% \8 z) L" F7 r1 e4 N– if this current remains less than 2,1 times the rated current of the fuse-link, the( w- u+ u1 w$ j
temperatures are measured after a steady state has been attained;
/ Q7 W ?; r3 [8 e- Y5 B; [5 y" [– if this current is either immediately 2,1 times the rated current of the fuse-link or more, or
p0 P! o9 b* W. L9 e- N# V. ]9 @reaches this value after a period of time equal to the maximum pre-arcing time for the3 x" s2 v* t1 x3 ^
relevant current through the fuse-link under consideration, both the fuse-link and the shortcircuit
* n, }+ d+ }( E' q( E5 x# qlink are removed after an additional time corresponding to the maximum pre-arcing
" c4 g. U0 {2 E2 h$ d6 I# f: Ctime of the fuse-link under consideration and the temperatures are measured immediately.
% }/ t( L2 I$ |, `- Y/ d' j$ e1 w5 p& E- M- j! A) W- [* B
以上是有关熔断体的操作问题,我想问的是:
, x+ w% Y8 b$ \7 ~1.为什么是2.1倍的额定电流值,不是1.5倍,2倍,也就是为什么是2.1不是其他值8 w7 h0 w$ [' X3 {1 d. Z. K, e
2.pre-arcing time 怎样计算呢? |
|