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本帖最后由 passagere 于 2017-6-29 05:25 编辑
4 y; R8 i F$ n# F- Jsheleason 发表于 2017-6-27 18:12
! K4 D$ d F- ?. R借楼问一下。有款灯具 输入线是3线 里面连接的内置电源。灯具外壳是金属 但是外壳没有接地。4 a9 Z+ o {) W8 q, J& \
。灯具的输入 ...
3 l: [5 ]0 A& D; f按60598,地线没有连接到可接触的金属部件上时,可以作为II类灯具(同时满足II类结构要求)。II类灯具不需要做接地连续性测试。GND到地线上不传导绝缘失效时的危险电流,所以不需要做。
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8 Q2 f6 [, l# e7 O8 Y9 @9 \8 |6 kGND上到地线,是为了功能或者电磁兼容的作用,不是为了传播电流的。如果I类灯具,且PCB上的铜箔作为传输路径时(I类灯具上也有功能接地部分,不是接到PCB上就一定对trace有大电流传播要求),那是需要额外验证大电流通过能力的。路径为:地线——PCB trace——可能带电的金属部件时,trace才可能传播大电流。
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3 p- f5 I5 z7 G在60598里找到条款,按II类灯具判就可以了。
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3 w+ ]- m6 `: s! Lclass II luminaire6 m6 ]# `3 `1 ]. D8 ?1 Y, E
luminaire in which protection against electric shock does not rely on basic insulation only, but in
+ n0 D/ D+ ]. z5 ]: ?5 g. lwhich additional safety precautions such as double insulation or reinforced insulation are
7 f/ f+ F8 S2 A, eprovided, there being no provision for protective earthing or reliance upon installation/ J+ G' x- e% a" @5 I& ^) U
conditions' u5 Q+ M+ h5 [5 w" z
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Note 3 to entry: If earthing is provided to assist starting, or for EMC reasons, but is not connected to an2 t3 E4 t# q+ \: w
accessible metal part, the luminaire may still be deemed to be of class II. Accessible metal parts in compliance with
1 E7 v$ U# u# Cthe appropriate IEC lamp specification and other metal parts not normally earthed and not normally accessible
N9 }* k+ A% L# u4 F) W4 p+ Iduring normal use are not regarded to be conductive parts which may cause an electric shock unless the tests of+ m: e1 b% x: n$ ]' Q
Annex A show them to be live parts.
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从上面条款可以看出,功能接地的灯具,满足要求时可以判为I类灯具。具体判定位I还是II,看结构特点和那个更容易实现、简单。! w- F, K7 W- A2 ?& Q6 n9 ^
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