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仔细阅读62368下面条款$ t% O8 ]! M! \& p( d! W- i: U
5.4.1.8 Determination of working voltage0 f K W/ O' F' E' ]( K& W
5.4.1.8.1 General+ X8 Z5 U/ B4 m
In determining working voltages, all of the following requirements apply:
& I* t, b4 D$ Y2 [* sa) unearthed accessible conductive parts are assumed to be earthed;
8 z/ t8 X1 T! t6 O% \6 i- S: l! |5 T7 X& db) if a transformer winding or other part is not connected to a circuit that establishes its
% s. K8 u5 j. ^" U. S4 C1 d( Zpotential relative to earth, the winding or other part are assumed to be earthed at a point by5 n# D3 L4 h) ~
which the highest working voltage is obtained;
" r, r$ Y7 _. o" yc) except as specified in 5.4.1.6, for insulation between two transformer windings, the highest5 b" l1 I' U( ^* l8 E
voltage between any two points in the two windings is the working voltage, taking into) D6 F' d, I M4 @
account the voltages to which the input windings will be connected;
' w' v% P% w% q: ^' a) h& `& J: Dd) except as specified in 5.4.1.6, for insulation between a transformer winding and another9 N: T- ~ @" u' `# O2 u
part, the highest voltage between any point on the winding and the other part is the working
1 c( @* D3 f# S6 u+ h$ b! F( `* Lvoltage;% y! d/ @( w% K+ y; E0 h, _
1 Z4 N) m, E, T0 e+ v! o9 n
e) where double insulation is used, the working voltage across the basic insulation is8 S, @, y( g. T Q+ i+ U
determined by imagining a short-circuit across the supplementary insulation, and vice
1 P1 j; K2 P6 k* j$ [$ Jversa. For double insulation between transformer windings, the short-circuit is assumed
- a, }( z* D6 B* z: y' nto take place at the point by which the highest working voltage is produced across the1 S* T: |, M& i! Q
other insulation;
$ z+ {- @/ u2 F- N4 H1 Uf) when the working voltage is determined by measurement, the input voltage supplied to the
\& j' r8 v' y8 E% {: [) @equipment shall be the rated voltage or the voltage within the rated voltage range that& K* A2 b+ l! {- J8 |4 Y# n" E
results in the highest measured value;
* d( B( J& S$ l4 Qg) the working voltage between any point in the circuit supplied by the mains and" D; j& z; x4 i5 A8 y! i
– any part connected to earth; and
* G6 e' j' E8 L4 `9 \– any point in a circuit isolated from the mains,5 |. {. }2 r; ~/ J
shall be taken as the greater of the following:
0 d$ c7 A8 D" b# K8 ^1 j– the rated voltage or the upper voltage of the rated voltage range; and
4 Q( M% a+ D( W8 |! c6 z! g– the measured voltage;
" w/ g0 u8 M* X" V6 n2 \h) when determining the working voltage for an ES1 or ES2 external circuit, the normal6 H" l# H6 Q. y+ K
operating voltages shall be taken into account. If the operating voltages are not known, the: r& q6 W m7 Z" l/ l P5 J' L* ^
working voltage shall be taken as the upper limits of ES1 or ES2 as applicable. Short8 X8 p' H0 u4 t o6 {, l5 j4 X
duration signals (such as telephone ringing) shall not be taken into account for determining; y$ Z' h( E' Q! O& P1 C* V
working voltage; d' N. V6 Q: W, |7 r4 ^* I
i) for circuits generating starting pulses (for example, discharge lamps, see 5.4.1.7), the7 u+ E0 v( A; d( u+ v: R) P
working voltage is the peak value of the pulses with the lamp connected but before the
1 J9 L7 I. L. C3 hlamp ignites. The frequency of the working voltage to determine the minimum clearance3 ?; ^3 P* F( O, l/ Q
shall be taken as less than 30 kHz. The working voltage to determine minimum creepage
8 y( _9 I9 g* ~* @; p) L" Pdistances is the voltage measured after the ignition of the lamp. |
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