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这个结构要保证两个条件,即IP和接地符合标准要求。, ^' m9 b! D& w
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对于接地问题,首先要做防松措施,保证接地连续性,还要检测接地电阻值有没有超出标准要求0.5欧姆。6 x$ | b4 J2 [ |+ m
4 d- f( X' I9 ?4 |- ~ o; U, V如图片结构,想利用灯体大身与封盖之间的螺丝做接地连续,但又要保证能符合IP要求,按标准要求,接地用途的部件是不能用于其它目的。
, ^+ H7 Z+ Z+ e0 w8 Q7 ~7 B(是不是出于成本考虑,不使用单独的接地螺丝和接地线)
! Z4 D( e2 Y6 E$ w如中间衬垫了非铜金属的又是在维修期间必须拆装的,潜在接地连续性及低电阻性将不能保证。) c3 A5 ~5 D s$ K
The earthing connections shall be of low resistance. , x/ J+ j! H0 |3 `" w
Self-tapping screws may be used to provide earthing continuity, provided they comply with the requirements given in 4.12.1. 8 v* H7 }0 U2 _- j2 Z7 H# n7 E
7.2.8 Either the screw or the other part of the earth terminal shall be made of brass or other non-rusting metal or a material with a non-rusting surface and the contact surfaces shall be bare metal.
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