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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
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$ b" P! E5 v' D6 k! I! X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?/ K; R+ N9 _! t4 p$ a5 o* J
( E: _8 H' E; t) }0 R0 [. K是依据什么?, C! R+ c! y. B: T- j) P; @( \
' [3 [+ }6 P+ _- s2 m7 T0 v如果划分到Class 2, 是不是需要标“回”符号呢?
' F Q+ z' K& t4 f7 C) nUL 60950 2.6.2 有对这个功能接地详细描述:& c6 L) T; d; V7 c2 s6 G3 v( b
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6 E( [" }% Y' d Q! s9 c
2.6.2 Functional earthing
& p# j! [6 H: K. Y& LIf FUNCTIONAL EARTHING of accessible or inaccessible conductive parts is necessary, all of the* j0 c* p( d2 |/ B
following apply to the FUNCTIONAL EARTHING circuit:) |+ G( A: c' H, f! s/ V
– the FUNCTIONAL EARTHING circuit shall be separated from parts at HAZARDOUS VOLTAGES in
. W4 y8 m- v$ E) M9 ~/ fthe equipment by either:5 d2 ?* ?5 q: Y
• DOUBLE INSULATION or REINFORCED INSULATION; or
6 L8 I! D+ i& U5 ?* w. N% M• a protectively earthed screen or another protectively earthed conductive4 \% `8 z& E, B. E Z- F
part, separated from parts at HAZARDOUS VOLTAGES by at least BASIC INSULATION;
& T! w) ~1 ^! z# x1 T; F& v8 Land
3 N8 N$ e: n0 ^3 Q; L6 G– it is permitted to connect the FUNCTIONAL EARTHING circuit to a protective earth terminal
+ W+ h0 c& X/ m0 x' e( q. For to a PROTECTIVE BONDING CONDUCTOR; and: M, u9 z( x0 w2 j
– wiring terminals to be used only for FUNCTIONAL EARTHING shall not be marked by the! X, A* p8 E# v6 D" [ ~4 t$ P$ D. P
symbol (60417-IEC-5017) or by the symbol (60417-IEC-5019), except that,, _% U& ?5 Y6 [
where a wiring terminal is provided on a component (for example, a terminal block) or
/ q z# @: y* J, Lsubassembly, the symbol is permitted; and
- S: d" l7 R, U6 x ^ bNOTE Other markings such as one of the symbols, (IEC 60417-5018 (DB:2002-10)) or (IEC 60417-5020+ j& D m9 g v
(DB:2002-10)), if appropriate, are permitted.: u$ W% T5 X6 ]* d P2 ]8 C
– for internal FUNCTIONAL EARTHING conductors, the colour combination green-and-yellow) p |! r4 Q7 W4 E5 B
shall not be used except in multipurpose preassembled components (for example,
+ {- i% {$ G0 c9 qmulti-conductor cables or EMC filters); and
. g, C* B; M! } Q% {+ u3 \– in a power supply cord where a conductor having green-and-yellow insulation is, g2 ]2 g' |' {7 w5 ]$ O4 q9 b
used only to provide a FUNCTIONAL EARTHING connection:" E# w3 e, t" f2 S& B0 g" P) A8 z4 c
• the equipment shall not be marked with the symbol (IEC 60417-5172
" V( F5 Z& A" g+ b3 [% z5 F(DB:2003-02)); and
; _# H" ]3 ?: k0 x1 S• there are no requirements other than those in 3.1.9 regarding the
4 q/ m9 Q, H2 V0 ?/ @# F. Dtermination of this conductor at the equipment end.7 s& C- ^4 ~3 m& ?) p
MARCH 27, 2007 CAN/CSA-C22.2 NO. 60950-1-07 ♦ UL 60950-1 89 |
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