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本帖最后由 passagere 于 2017-6-29 05:25 编辑 - D& f5 g0 p, j; k1 s
sheleason 发表于 2017-6-27 18:12 / w# F0 x2 J9 C& l3 @' h, V- a
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。6 `# J3 j: q( X6 ^1 t; S
。灯具的输入 ... 3 W$ |, ^' F8 C# h2 w9 a1 H5 q
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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GND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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7 \- t/ S* E# e/ A) `在60598里找到条款,按II类灯具判就可以了。 G2 f0 }7 Y$ f# q% G& y' c
1.2.23
* H K$ q5 p- b3 Sclass II luminaire9 d* t. b3 t- H
luminaire in which protection against electric shock does not rely on basic insulation only, but in
+ a1 W! H; H: k$ q8 w* b6 M. iwhich additional safety precautions such as double insulation or reinforced insulation are
4 Q- p' _+ E$ F0 z' }4 L6 pprovided, there being no provision for protective earthing or reliance upon installation
, n. W* ?9 r/ `/ p& g/ B. oconditions
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Note 3 to entry: If earthing is provided to assist starting, or for EMC reasons, but is not connected to an Z# ]5 n9 r* s5 n% S( N% K% H
accessible metal part, the luminaire may still be deemed to be of class II. Accessible metal parts in compliance with" a% ^; x# T4 } B/ p; h2 L
the appropriate IEC lamp specification and other metal parts not normally earthed and not normally accessible
; _3 y# r) f3 Sduring normal use are not regarded to be conductive parts which may cause an electric shock unless the tests of" g0 U% u7 G% ^9 P
Annex A show them to be live parts.. H5 a% Y8 F) ^3 o* E: |6 O/ \( p7 z
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8 p; c% ^; H% w. p' ?1 J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。
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