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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7 r# R% q' ^" p( X' ]7 m
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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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, n$ A h$ W7 P: s是依据什么?8 ~4 Y5 @7 K7 u+ M
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如果划分到Class 2, 是不是需要标“回”符号呢?
' r9 ]) ?. k1 Z$ s7 c' ^. m: lUL 60950 2.6.2 有对这个功能接地详细描述:
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2.6.2 Functional earthing
/ s7 n) m7 j$ b" ]# J, m& V* }If FUNCTIONAL EARTHING of accessible or inaccessible conductive parts is necessary, all of the
7 \: ~' C( C- w& _ i/ ]) |& T! {following apply to the FUNCTIONAL EARTHING circuit:
5 Y. ~# W* q2 P– the FUNCTIONAL EARTHING circuit shall be separated from parts at HAZARDOUS VOLTAGES in
2 Z6 d' W8 A. B+ w1 }+ a- H$ s( @the equipment by either:$ S3 y6 d; P' ^) C( a7 F
• DOUBLE INSULATION or REINFORCED INSULATION; or
; S& W: O0 H! ~5 \3 g• a protectively earthed screen or another protectively earthed conductive; p3 [' S) b6 G6 k1 G
part, separated from parts at HAZARDOUS VOLTAGES by at least BASIC INSULATION;4 z, i& | j: S* m, g/ Y! a) @
and9 n* S$ b( b2 _. |7 I- T. f2 o
– it is permitted to connect the FUNCTIONAL EARTHING circuit to a protective earth terminal
8 w( N- V8 o* @, v5 F$ I5 ~or to a PROTECTIVE BONDING CONDUCTOR; and
/ D, b& m) U5 }– wiring terminals to be used only for FUNCTIONAL EARTHING shall not be marked by the7 I! L0 G/ \. g# T. R, Z% N
symbol (60417-IEC-5017) or by the symbol (60417-IEC-5019), except that,
- c* O7 I1 i% a- D% X* fwhere a wiring terminal is provided on a component (for example, a terminal block) or
" V1 u7 u7 i- k1 D# [5 |+ e asubassembly, the symbol is permitted; and L) D- U* l4 D) E. B( O$ `+ [! l
NOTE Other markings such as one of the symbols, (IEC 60417-5018 (DB:2002-10)) or (IEC 60417-5020* i0 w0 d7 x0 ^
(DB:2002-10)), if appropriate, are permitted.- w: |7 R {/ V2 j
– for internal FUNCTIONAL EARTHING conductors, the colour combination green-and-yellow( b6 h, f7 H1 ^3 |8 ^% i/ y7 }+ U
shall not be used except in multipurpose preassembled components (for example," C! g& M% ?) p! ~
multi-conductor cables or EMC filters); and
& Q! U, Y/ o/ i1 b- Y– in a power supply cord where a conductor having green-and-yellow insulation is3 f. _3 a9 ~8 \/ l. h
used only to provide a FUNCTIONAL EARTHING connection:* Y/ @& A m% m1 `- y: r: T
• the equipment shall not be marked with the symbol (IEC 60417-5172) d) p6 \: g- a5 Z
(DB:2003-02)); and7 c3 l& i; Y" M' D
• there are no requirements other than those in 3.1.9 regarding the3 h# b4 I1 _ C9 x) R
termination of this conductor at the equipment end.1 ^. u6 S) V1 C, [: ~
MARCH 27, 2007 CAN/CSA-C22.2 NO. 60950-1-07 ♦ UL 60950-1 89 |
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