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29.1 Clearances shall not be less than the values specified in Table 16, taking into
& {; V" r1 g5 t7 j3 Kaccount the rated impulse voltage for the overvoltage categories of Table 15, unless, for
" N$ R) A8 l6 _( obasic insulation and functional insulation, they comply with the impulse voltage test of
l7 K, _4 v. |" n1 DClause 14. However, if the construction is such that the distances could be affected by wear,0 ?: m6 u2 R' `4 P2 x& z$ @
by distortion, by movement of the parts or during assembly, the clearances for rated impulse
- t5 K7 m1 g% e2 U9 b1 o3 Rvoltages of 1 500 V and above are increased by 0,5 mm and the impulse voltage test is not9 W( N, z" \) Z. f2 Y
applicable.
' U0 r* J5 _: U- i- ZThe impulse voltage test is not applicable when the microenvironment is pollution degree 3 or/ f9 f8 E1 E g
for basic insulation of class 0 appliances and class 0I appliances."0 C1 N$ q* d; W% U8 [
% e% z4 }6 c1 `5 q# l+ |7 D14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
: o; u; e* R" s# l/ M1 \
( y4 ~& o \9 C9 c) @, u( D污染等级, 一般暴露在外面, 有电机。 的部位一般判3类8 o1 H: L/ Z4 G, p9 f
有一定的密封, 一般不会有灰尘进去就可以判2类。) Q5 L/ L- h/ o7 D0 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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