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29.1 Clearances shall not be less than the values specified in Table 16, taking into+ S4 v+ d9 P- L9 ^
account the rated impulse voltage for the overvoltage categories of Table 15, unless, for, R! Q1 U- e ~7 y$ y3 x
basic insulation and functional insulation, they comply with the impulse voltage test of9 q! a" ]4 C7 Z
Clause 14. However, if the construction is such that the distances could be affected by wear,, I& k, I: e1 S
by distortion, by movement of the parts or during assembly, the clearances for rated impulse5 ^. B0 H: f5 d9 f+ Q. K$ q0 s
voltages of 1 500 V and above are increased by 0,5 mm and the impulse voltage test is not
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The impulse voltage test is not applicable when the microenvironment is pollution degree 3 or5 y; C3 R1 M: S* _# u* @3 B7 T
for basic insulation of class 0 appliances and class 0I appliances."0 a& c& G6 L4 o9 X9 J8 z% f! s0 w
" F% v4 j2 j& r' \+ x, f14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
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污染等级, 一般暴露在外面, 有电机。 的部位一般判3类
5 r+ _: W# V _有一定的密封, 一般不会有灰尘进去就可以判2类。
+ Z; B2 @- _4 j% o* { \# c& n& F1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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