|
在IEC60950-2005 中,有如下内容:+ L3 A& q: J. X$ L
6 N- p6 @" z5 N, e1.5.9.2 Protection of VDRs
* ]% |- P+ P. _* I5 {/ MFor protection against
2 w; S" m5 |3 `6 s' X! J􀀐 temporary overvoltages above the maximum continuous voltage,
7 A5 y' W, b1 x2 k% ~2 `; V# _$ d. y􀀐 thermal overload due to leakage current within the VDR, and
{* e" n' K& ? k4 @7 w T* ]􀀐 burning and bursting of the VDR in the event of a short-circuit fault,9 F: X" b6 S6 p$ _3 V
an interrupting means having an adequate breaking capacity shall be connected in series with
8 x) O- a5 U9 q, V! Ythe VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.
, H, {+ e+ D6 `8 N! U. ANOTE 1 For temporary overvoltages from the AC MAINS SUPPLY, see IEC 60664-1.
$ V( N: J& \( x% {NOTE 2 During the lifetime of a VDR the leakage current increases with the number of switching cycles in the
5 _* W; c. A; H% v) bVDR. This leakage current causes a permanent and continuously increasing temperature stress, which can cause
0 f; N) b0 C7 H# F8 X+ H% U8 W) cthe VDR to burn or burst.
3 _3 ]; y; t. K. q% L% @& gCompliance is checked by inspection./ d$ K: ~7 j5 W' v0 m$ b7 O3 t' P
7 h" ?6 f! f" }+ q- i' j
关于这部分的内容,不知道大家是怎么理解的,我现在想向大家请教的是关于 MOV,也就是所说的压敏电阻的保护。不知道大家有没有遇到过,如果在功率比较大的产品中使用到MOV的话,不管是跨接在L-N之间还是L-G之间,是不是都一定要对MOV进行保护?比如说用一个fuse和MOV串联。 |
|