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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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7 k: f. t! }: _; G" m7 ?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?# a3 E: O# m' y; r$ J c7 B5 {/ r
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是依据什么?1 A. c% a% p# d5 E8 b8 S5 ^
5 W$ x7 T! ^! Y' q+ I1 F/ u如果划分到Class 2, 是不是需要标“回”符号呢?$ ]# Z" s. Z2 _* V* R$ z! x
UL 60950 2.6.2 有对这个功能接地详细描述:
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' u; M$ U2 a' f2.6.2 Functional earthing
, ?$ a* r' v+ \6 {# y Y2 {, D1 o$ `If FUNCTIONAL EARTHING of accessible or inaccessible conductive parts is necessary, all of the
* D+ Y8 t5 O) V: g& h$ Rfollowing apply to the FUNCTIONAL EARTHING circuit:( i! B+ l2 U9 B0 ~
– the FUNCTIONAL EARTHING circuit shall be separated from parts at HAZARDOUS VOLTAGES in
8 Q0 h# `4 [; S, B! E7 r- bthe equipment by either:
4 y6 w8 A3 ?( o D5 N2 {( h• DOUBLE INSULATION or REINFORCED INSULATION; or
- e& Z* o- R3 m2 ~* C; {! j• a protectively earthed screen or another protectively earthed conductive2 A8 L3 @7 ?" S' @, t
part, separated from parts at HAZARDOUS VOLTAGES by at least BASIC INSULATION;
: v8 w6 _. m+ R5 Kand
: o1 B( |5 W9 r8 G3 U3 ?3 ^* Q– it is permitted to connect the FUNCTIONAL EARTHING circuit to a protective earth terminal1 [9 G. o& @0 g/ L
or to a PROTECTIVE BONDING CONDUCTOR; and; F# L+ v$ k) Q/ H* u) ]
– wiring terminals to be used only for FUNCTIONAL EARTHING shall not be marked by the; B5 s+ F$ E- `$ n- n
symbol (60417-IEC-5017) or by the symbol (60417-IEC-5019), except that," {3 E8 J; y- u7 l G, J
where a wiring terminal is provided on a component (for example, a terminal block) or5 g! S& |5 {' y0 Y7 g& m# a1 E& ~
subassembly, the symbol is permitted; and
: Y. c1 A; O% K0 ONOTE Other markings such as one of the symbols, (IEC 60417-5018 (DB:2002-10)) or (IEC 60417-5020
+ \! Z( c& O7 y% H. P: m; j% @(DB:2002-10)), if appropriate, are permitted.
/ @1 q1 c0 f' I: d0 Z8 m/ W+ j5 b– for internal FUNCTIONAL EARTHING conductors, the colour combination green-and-yellow- {; ^) p: N2 w8 J
shall not be used except in multipurpose preassembled components (for example,) ^4 q& q1 @5 a6 u2 @9 T. ~, _
multi-conductor cables or EMC filters); and
" b$ @" Y) r- n: P$ ^! j– in a power supply cord where a conductor having green-and-yellow insulation is8 R' ^5 D' a6 N, s+ f# E) M& T
used only to provide a FUNCTIONAL EARTHING connection:
. j: T) X" G. N: X6 K9 D) J• the equipment shall not be marked with the symbol (IEC 60417-51720 B+ b+ B* v1 K& `9 K
(DB:2003-02)); and+ Z+ _! k; V+ A% @
• there are no requirements other than those in 3.1.9 regarding the
- h; b6 _) ~# p- A c7 h5 l& _termination of this conductor at the equipment end.' K- I9 F0 O7 _" J0 v7 T3 O
MARCH 27, 2007 CAN/CSA-C22.2 NO. 60950-1-07 ♦ UL 60950-1 89 |
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