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仔细阅读62368下面条款2 M1 `- e! ?# I5 T
5.4.1.8 Determination of working voltage
( w4 Z' E" [# {( G$ Q/ d' n5.4.1.8.1 General
. Z( H5 e9 \# j( k" v$ NIn determining working voltages, all of the following requirements apply:
, R6 |. i+ @; {; E- Ga) unearthed accessible conductive parts are assumed to be earthed;' A4 J* S: w+ F$ b/ }
b) if a transformer winding or other part is not connected to a circuit that establishes its* Q' r5 D- Z1 T
potential relative to earth, the winding or other part are assumed to be earthed at a point by
! C% ]5 x! R5 vwhich the highest working voltage is obtained; k- r k/ v, g- E+ l
c) except as specified in 5.4.1.6, for insulation between two transformer windings, the highest
+ y1 l5 z2 K* A/ Vvoltage between any two points in the two windings is the working voltage, taking into
# @3 F* B0 n) ]* E+ l# a' p" saccount the voltages to which the input windings will be connected;% O4 l0 A5 h& {3 s* J( f) ^
d) except as specified in 5.4.1.6, for insulation between a transformer winding and another6 P& c1 y2 l6 C
part, the highest voltage between any point on the winding and the other part is the working; Y, s0 x& s4 J2 ^- E$ Y, k/ I
voltage;/ f2 ~ T" R" d, G& x
; P4 F+ |4 s7 |
e) where double insulation is used, the working voltage across the basic insulation is
8 { r7 m1 |& u7 D' }% [9 ~determined by imagining a short-circuit across the supplementary insulation, and vice' W+ x2 X+ B2 A: l0 l7 g
versa. For double insulation between transformer windings, the short-circuit is assumed8 _+ T+ J. ?: ~; L0 E+ R3 J9 m: d
to take place at the point by which the highest working voltage is produced across the
0 w+ @2 W1 @' yother insulation;
) c; J' O6 x* X. }f) when the working voltage is determined by measurement, the input voltage supplied to the
5 }2 E' v% R, V7 o( G+ J1 V% \equipment shall be the rated voltage or the voltage within the rated voltage range that1 G' |& s# d2 Q/ V; n. h
results in the highest measured value;
% x: U' P$ B+ o1 v7 H! W! N7 {g) the working voltage between any point in the circuit supplied by the mains and
4 y5 Y4 Q( k; G2 B– any part connected to earth; and1 B0 D3 x( d+ I: L* F7 e, p! T4 }+ f* Z
– any point in a circuit isolated from the mains, {* _% W0 g& _5 Y+ Q
shall be taken as the greater of the following:& i( y: t! K9 J0 R( u/ l$ X1 [
– the rated voltage or the upper voltage of the rated voltage range; and6 ^2 H' L) t7 P5 @ O( V
– the measured voltage;
2 d) u; q, j) u( H. |& g% jh) when determining the working voltage for an ES1 or ES2 external circuit, the normal' N% p9 u2 c4 s8 H
operating voltages shall be taken into account. If the operating voltages are not known, the3 y E) R+ Q; |- t$ G2 g! x
working voltage shall be taken as the upper limits of ES1 or ES2 as applicable. Short5 q; X' K% d# |* j. M" `
duration signals (such as telephone ringing) shall not be taken into account for determining% k8 W' m$ R F2 L
working voltage;8 X! H3 Q+ C) j" H8 X+ O( r
i) for circuits generating starting pulses (for example, discharge lamps, see 5.4.1.7), the
0 g6 ^! a, q3 y: o6 B, K# Zworking voltage is the peak value of the pulses with the lamp connected but before the
. t, x9 S e O/ K1 `2 G) \; klamp ignites. The frequency of the working voltage to determine the minimum clearance
# C1 d% C: ]/ A- U( j5 g2 B( ]+ eshall be taken as less than 30 kHz. The working voltage to determine minimum creepage
/ c6 G. U1 J9 b( o/ }3 m' h. }+ Ldistances is the voltage measured after the ignition of the lamp. |
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