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标题: DSH 280 Use of taptile screw to provide earthing continuity [打印本页]
作者: 小米    时间: 2012-9-14 13:16
标题: DSH 280 Use of taptile screw to provide earthing continuity
DSH 280
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Use of taptile screw to provide earthing continuity: _! @4 ^$ z$ i7 O$ a: g% W2 U
28.3% ^! B4 `. }( c' |6 e4 b; ]! a) _, a
60335-1(ed.3)4 }8 Q& s# v" \+ z3 e! n8 Q
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Standard: IEC 60335-1, Ed. 3.0 Sub clause: 28.3 Sheet n. 280( |1 K$ L8 [! Q4 O  F0 e1 |* n
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Subject: Use of taptile screw to$ p  n+ G% N. T3 @. m# C
provide earthing continuity
* u1 I5 v0 U$ O) [8 D# QKey words:, s4 c1 w7 B0 x
- taptile screw
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Decision n. 20( Z- `% r& q* x
taken0 I/ D! {4 u+ E  e+ u+ ^& x6 s
at 36th meeting/1999
$ U, ]' Y8 F! J$ J' jQuestion: A taptile screw is a screw providing self tapping during screwing.
( T5 n  D- N* l; B, S' [& dIs this type of screw considered as a thread cutting or space thread screw regarding+ \% Y6 t) ]5 w5 j, G: y1 m
requirements of sub clause 28.3 (at least two screw are necessary to provide
/ G5 @0 L: r. ?- {: w5 i: {% Uearthing continuity) or is considered as a machine screw (only one screw is; ]& r  P( h2 ~3 S9 k& g
sufficient)?
6 J0 m% B# Q3 A(See drawing on page 2).8 [, ?# U: b* K+ \
Decision: Only one taptile screw is enough to provide earthing continuity, if the screw has& I7 d) i  n* i% F: Q
the same thread than a machine screw and if the shape is round.
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) I/ O1 e9 s) c, o( C2 Z$ \[attach]75941[/attach]$ [( e2 d8 S9 k5 z, q




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