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29.1 Clearances shall not be less than the values specified in Table 16, taking into
9 e; w# Z/ i. laccount the rated impulse voltage for the overvoltage categories of Table 15, unless, for: D" t' R: C2 s: L0 _( Y- S6 f
basic insulation and functional insulation, they comply with the impulse voltage test of
/ `: x, o& b/ w5 s/ vClause 14. However, if the construction is such that the distances could be affected by wear,
& V! h, C! {) \" V6 ?" mby distortion, by movement of the parts or during assembly, the clearances for rated impulse5 c/ j8 R L9 i A) J) v
voltages of 1 500 V and above are increased by 0,5 mm and the impulse voltage test is not5 W. ?6 t: i. n% b* X
applicable.
/ s; {( b a; j8 U3 WThe impulse voltage test is not applicable when the microenvironment is pollution degree 3 or
0 f/ V& {9 Q, T, I2 v4 cfor basic insulation of class 0 appliances and class 0I appliances."- t% a4 ^% K1 d
3 h, D1 a6 D2 r0 `. \0 n# m14章对功能绝缘和基本绝缘适用,电气间隙过不了,一般认证机构不会去做14章的。直接就failed了: c2 D& m: p' T
6 J+ A( f+ f8 x( M3 B污染等级, 一般暴露在外面, 有电机。 的部位一般判3类
4 G1 q6 X9 l5 U. o% _* D5 `- W有一定的密封, 一般不会有灰尘进去就可以判2类。2 L; n% H; N7 V6 R7 D) {3 l I( M
1类一般很少判, 除非象继电器一样完全密封的才看作1类。 |
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