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本帖最后由 火水晶 于 2015-3-4 10:51 编辑 * k6 f4 d8 M4 f1 K8 S! P
1 M5 @ D) k$ K- ?7 H如标题描素,在UL458中经常可以看到Dead-metal 和 live-metal 两个单词,如下文节选。28.1.2 With reference to Exception No. 1 to 28.1.1 and with reference to UL 840, reduced through-air spacings are based on the use of insulating materials that resist arc tracking and the degree of conductive pollution present in the environment of use. They are applicable to a unit in which the transient voltages are known and are controlled by a transient suppressive device and to a unit that withstands an impulse withstand voltage test. The spacing requirements of UL 840 shall not be used for field-wiring terminals and spacings to a dead metal enclosure.
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j! l# o& M! ^% c28.1.7 With reference to Exception No. 2 to 28.1.1 concerning conformal coatings, minimum spacings of 1/32 in (0.8 mm) between adjacent foils shall be maintained. A conformal coating on printed wiring boards is not considered as insulation in lieu of spacings between a foil on a printed wiring board and uninsulated live-metal parts of opposite polarity or to uninsulated dead-metal parts.
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这两个单词怎么翻译啊?大家怎么看?1 v' @9 |: \& G+ C0 X
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