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请问论坛里面有没有对Class 2+ 功能接地结构比较熟悉的,讨论一下$ q y. G# d8 }
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像这种2类设备带功能接地的,一般认证机构划分到Class I 还是Class II呢?
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& E j" m3 g4 G) O6 ~是依据什么?+ Q4 D8 D0 T( }( H
- l) G/ ~+ ^7 P" \如果划分到Class 2, 是不是需要标“回”符号呢?
! Q$ K1 Q8 H$ @6 [+ J+ rUL 60950 2.6.2 有对这个功能接地详细描述:
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0 ?; q' \: D1 E1 u2.6.2 Functional earthing
L; s$ q9 x9 y0 w2 I1 d& eIf FUNCTIONAL EARTHING of accessible or inaccessible conductive parts is necessary, all of the3 X1 \) c! ?2 L- h" O s0 w- i# k
following apply to the FUNCTIONAL EARTHING circuit:! T; O e4 ^! o" o+ p+ @
– the FUNCTIONAL EARTHING circuit shall be separated from parts at HAZARDOUS VOLTAGES in
; M5 v- H6 j# X$ ?$ athe equipment by either:
: _& S. C0 ]% n; O2 V3 |• DOUBLE INSULATION or REINFORCED INSULATION; or' |3 h: h% w: `' C
• a protectively earthed screen or another protectively earthed conductive. a# U2 ~* v, K5 N& b% T7 u- R
part, separated from parts at HAZARDOUS VOLTAGES by at least BASIC INSULATION;
/ J; E1 ~6 U- W5 ~/ E/ Wand7 q4 D" m& @. e1 a
– it is permitted to connect the FUNCTIONAL EARTHING circuit to a protective earth terminal% p5 S; |# V/ M
or to a PROTECTIVE BONDING CONDUCTOR; and7 h! u$ s/ f9 m6 }7 p
– wiring terminals to be used only for FUNCTIONAL EARTHING shall not be marked by the
6 ?/ _$ G4 X2 qsymbol (60417-IEC-5017) or by the symbol (60417-IEC-5019), except that,/ ?+ H% `* g; u) i. K7 Y7 A) E( ?
where a wiring terminal is provided on a component (for example, a terminal block) or6 f* ~! u/ C' X$ J$ o8 i5 O; ~0 R5 H
subassembly, the symbol is permitted; and
. h l* N( s& x V" x- dNOTE Other markings such as one of the symbols, (IEC 60417-5018 (DB:2002-10)) or (IEC 60417-50206 \& q, ^8 c& @# @) Q
(DB:2002-10)), if appropriate, are permitted.1 ~( X5 m F2 E! |4 ~/ @
– for internal FUNCTIONAL EARTHING conductors, the colour combination green-and-yellow7 ~! v# Z# q$ c
shall not be used except in multipurpose preassembled components (for example,: [) t6 a- q! F4 F( H# N
multi-conductor cables or EMC filters); and
* R$ S+ {( x4 T/ c) F( I0 W3 d– in a power supply cord where a conductor having green-and-yellow insulation is
# V& f& K2 N) W& oused only to provide a FUNCTIONAL EARTHING connection:
0 x$ k* {/ ]1 U' s8 w• the equipment shall not be marked with the symbol (IEC 60417-5172
( K4 ^9 ~! M0 d5 g0 q2 e. l(DB:2003-02)); and
/ ^" t9 T0 ?8 B* Y• there are no requirements other than those in 3.1.9 regarding the
( V3 W1 w) H0 H, P. s/ Xtermination of this conductor at the equipment end.
/ _8 F8 a6 ~- V% A5 v1 O# {MARCH 27, 2007 CAN/CSA-C22.2 NO. 60950-1-07 ♦ UL 60950-1 89 |
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