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在IEC60950-2005 中,有如下内容:
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! N3 y! B# N# u7 b. ~$ I1.5.9.2 Protection of VDRs- C5 P; ^+ R; B2 [$ O
For protection against
) W' c, M4 B0 P! K/ b3 P* Y, Q0 G􀀐 temporary overvoltages above the maximum continuous voltage,
0 ]: I& Z6 e, a" E* @' L$ b􀀐 thermal overload due to leakage current within the VDR, and1 s$ n; F8 W/ u7 o1 K
􀀐 burning and bursting of the VDR in the event of a short-circuit fault,
8 ?% {$ P3 S1 v( G% K4 [" v& Gan interrupting means having an adequate breaking capacity shall be connected in series with
" }( @9 B, G; m( ~) \the VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.- X8 d5 R, q. W7 a% f, K
NOTE 1 For temporary overvoltages from the AC MAINS SUPPLY, see IEC 60664-1.
" W+ t' P) c7 Q1 N) M5 b8 _, aNOTE 2 During the lifetime of a VDR the leakage current increases with the number of switching cycles in the
# ]* t+ o: P: z9 H- fVDR. This leakage current causes a permanent and continuously increasing temperature stress, which can cause0 T \# k: ]3 @7 l' Z
the VDR to burn or burst.
2 b+ i; `: [& j7 h, C* ZCompliance is checked by inspection.
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$ C; R D- {8 W8 ~3 }3 p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。 |
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