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标题: DSH 300 Protective Impedance [打印本页]
作者: 小米    时间: 2012-9-19 15:05
标题: DSH 300 Protective Impedance

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DSH 300* I( R0 w7 g$ `' Y
Protective Impedance
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6.5.3) b) d3 k3 x3 ]$ b3 t: ?( Q
61010-1(ed.1);am1;am2' [, E2 l3 t6 w, r

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0 V# E% l' {" c, J. T) u' M' {Standard:  |, I5 O" f* y( F& b) j7 J3 G
IEC 61010-1:1990! \3 m. ^( q5 O( b
+A1:1992+A2:1995
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( ~; x, u( b- Q) |Sheet n. 300
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Protective Impedance) e0 x+ g  d' o5 u8 E( r% Q) g
Key words:/ u" B; u  B$ v
- Shock/ z* `  r9 j5 h" R
- Impedance
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Decision taken by# s* E& x6 [3 l" D& ^; a6 Y9 Y' n
ETF3 and confirmed7 ~8 e; s% ^/ X8 M6 r1 K
by CTL at its 38th2 U* b6 P9 u( _/ V3 G* Y
meeting, in Toronto1 W' G9 z7 s; x+ i/ `. ]
Question:
% s$ ]- z6 `" bWhere a component acts as protective impedance in single fault condition, should it be rated6 v' z2 d( c5 I' G/ {1 w% A9 W
for this function? An example is a component in an accessible secondary circuit which may# e0 |- h* @7 B& D" r
be made hazardous live by the failure of a creepage or clearance distance.- B, l! Y3 T( }" a; w' C
Decision:) E3 g- H# l0 s! h( {: J
Such components should be rated for the single fault condition.3 y2 D& ~. i1 K
Explanation:% N- ?( [: `; M! q4 S' Y
The safety of the user will be dependent on the operation of these devices. It will, however,4 Z. ~# t: l3 R7 N5 b' Q
be preferable for the design to avoid this circumstance as the integrity of the components is
" i. T1 T$ d& W# x. f5 B+ hnot defined.8 H* q9 I! b; R& d
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