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29.1 Clearances shall not be less than the values specified in Table 16, taking into, Z6 @% p3 K0 |" h
account the rated impulse voltage for the overvoltage categories of Table 15, unless, for4 t8 b3 ~. ^2 W" E, v2 \
basic insulation and functional insulation, they comply with the impulse voltage test of
1 M( @& M0 p3 j8 d- H! {Clause 14. However, if the construction is such that the distances could be affected by wear,6 j `; W& h1 v) j7 |" X) n
by distortion, by movement of the parts or during assembly, the clearances for rated impulse3 t: S' Q3 p$ Z0 G- T, Z
voltages of 1 500 V and above are increased by 0,5 mm and the impulse voltage test is not$ v7 j& }5 W0 T8 S" K" N
applicable.
: A; W% s. t7 [- [) AThe impulse voltage test is not applicable when the microenvironment is pollution degree 3 or
# u5 s+ X6 E+ d% lfor basic insulation of class 0 appliances and class 0I appliances."
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14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
, Z8 v0 b* h9 ^* C- G: |8 Q" ?& K# R2 E! I) X
污染等级, 一般暴露在外面, 有电机。 的部位一般判3类& M& Z9 e$ a2 O9 t4 g( i X
有一定的密封, 一般不会有灰尘进去就可以判2类。. i1 I* t2 H K8 ]7 Q8 {: v
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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