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楼主 |
发表于 2008-7-18 10:52
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PTC是属于半导体性质的,是会导电的,所以tracking试验不适用,所以只能按最差的3B了。
5 ` R; {. a( F9 ~. c6 f! m8 o如果按照污染等级2的确就没这个问题了,但是我们是按照P3考核, i' \' P. w% O$ w
pollution degree 2: only non-conductive pollution occurs, except that occasionally a, t: f/ W; M, @( c
temporary conductivity caused by condensation is to be expected;
% t/ H% p' }8 [pollution degree 3: conductive pollution occurs or dry non-conductive pollution occurs that& d+ O$ U8 r0 R/ x h$ C
becomes conductive due to condensation that is to be expected;) n$ q, [+ h1 B5 X+ }- |
PTC是暴露在空气中的(灰尘颗粒算导电的还是不导电的?),我觉得还是算作P3比较合理。 |
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