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在IEC60950-2005 中,有如下内容:. |9 J9 S" G: ~3 M
0 H$ ^# z! b5 G# h6 J' |: `1.5.9.2 Protection of VDRs
* [6 i- @9 n: AFor protection against
1 B% L% g, M; _% r3 c# B􀀐 temporary overvoltages above the maximum continuous voltage,
0 \! j4 h: Y4 a# V6 N􀀐 thermal overload due to leakage current within the VDR, and
; N1 L9 i# \% v) U3 Z$ y$ s􀀐 burning and bursting of the VDR in the event of a short-circuit fault,0 D O/ [4 p) N4 e
an interrupting means having an adequate breaking capacity shall be connected in series with
" f+ t, I# e/ R- J$ B6 R3 j9 }the VDR. This requirement does not apply to a VDR in a LIMITED CURRENT CIRCUIT.
1 |9 R3 Q1 e+ K& K% ]. U: sNOTE 1 For temporary overvoltages from the AC MAINS SUPPLY, see IEC 60664-1.
+ U0 I, B2 G8 I# a DNOTE 2 During the lifetime of a VDR the leakage current increases with the number of switching cycles in the
& w6 R9 ?& _% V) FVDR. This leakage current causes a permanent and continuously increasing temperature stress, which can cause) m) T- Y( X( a- l: O
the VDR to burn or burst.
/ B! m" `+ ~- f k& ~* NCompliance is checked by inspection.
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$ {: U0 {: [9 q1 G+ Q6 u/ f, Q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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