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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。
L5 i6 ~8 C4 W8 G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3 x( f" v$ J3 d5 V! W9 @, m3 E
pollution degree 2: only non-conductive pollution occurs, except that occasionally a7 d: Q% Q6 i' [$ Q) N0 k+ A2 u
temporary conductivity caused by condensation is to be expected;. I, K6 }; p/ t: K: n0 u
pollution degree 3: conductive pollution occurs or dry non-conductive pollution occurs that9 L3 E2 H9 ^9 b) F
becomes conductive due to condensation that is to be expected;9 D! Q+ {. R. i4 U6 I y& q& e; J
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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