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仔细阅读62368下面条款
0 N- U8 y) v5 F4 g5 @5.4.1.8 Determination of working voltage
: G, j' [6 g/ o5.4.1.8.1 General, ~+ q; v* ]; `. C, ?+ N
In determining working voltages, all of the following requirements apply:
/ e( j9 m+ I, x2 Q" D8 Pa) unearthed accessible conductive parts are assumed to be earthed;
$ m3 e6 Q# W! Q5 c+ L! db) if a transformer winding or other part is not connected to a circuit that establishes its
4 C R# h6 y5 X% b9 Cpotential relative to earth, the winding or other part are assumed to be earthed at a point by9 a' v/ I! d+ W% f2 u4 I. |( Z- S
which the highest working voltage is obtained;# O% A* [6 `5 q) m
c) except as specified in 5.4.1.6, for insulation between two transformer windings, the highest$ B/ H, W+ E3 [: C1 q9 ?/ F8 T! g
voltage between any two points in the two windings is the working voltage, taking into
9 O6 Y! e2 Z) h. Aaccount the voltages to which the input windings will be connected;* Z- _0 i& ]+ w% B9 K7 g" v
d) except as specified in 5.4.1.6, for insulation between a transformer winding and another
: D" y8 W9 S5 l. f( }0 k4 _( F" Epart, the highest voltage between any point on the winding and the other part is the working
9 q3 O* G# l. D9 j8 b1 c: Cvoltage;, T* q) j% a7 w7 ]8 W* w! G, R
% o: k! m/ z. @6 Qe) where double insulation is used, the working voltage across the basic insulation is% k: G" H* M6 b, D5 u N, F$ y8 l# J
determined by imagining a short-circuit across the supplementary insulation, and vice1 i$ s$ j, N0 d$ ]
versa. For double insulation between transformer windings, the short-circuit is assumed
+ l0 _! I+ r. K6 k! gto take place at the point by which the highest working voltage is produced across the
7 B2 o/ H5 W% p$ Z8 `* Y3 \other insulation;
+ Y# P1 p( J* Q) z5 sf) when the working voltage is determined by measurement, the input voltage supplied to the
3 |0 l3 E0 t2 I7 t8 c- T& d1 zequipment shall be the rated voltage or the voltage within the rated voltage range that
9 T4 a O! m' M8 l3 X3 Lresults in the highest measured value;" d6 b) D+ `$ M# M
g) the working voltage between any point in the circuit supplied by the mains and
1 k5 Z; s. G" f– any part connected to earth; and
3 S! u- F4 M9 C% A7 ]– any point in a circuit isolated from the mains,0 j- B# K: q! ~9 N+ G, B
shall be taken as the greater of the following:! N' {, G! H/ z' b
– the rated voltage or the upper voltage of the rated voltage range; and
: ~+ y- |7 [7 l7 S# Z4 T– the measured voltage;+ N! C2 T d- D1 `2 H7 t
h) when determining the working voltage for an ES1 or ES2 external circuit, the normal
' G2 A. O2 l% N4 n9 d8 yoperating voltages shall be taken into account. If the operating voltages are not known, the+ `& A; g" ?' q2 ]7 F6 E
working voltage shall be taken as the upper limits of ES1 or ES2 as applicable. Short3 @1 P2 M0 V$ ?
duration signals (such as telephone ringing) shall not be taken into account for determining
; f" e( `/ T' f9 {) H! ~working voltage;
" _! Y! E$ ~# Bi) for circuits generating starting pulses (for example, discharge lamps, see 5.4.1.7), the5 [8 i4 H9 A( u! L
working voltage is the peak value of the pulses with the lamp connected but before the
" {- W2 S$ }" u0 W- A. n {. alamp ignites. The frequency of the working voltage to determine the minimum clearance
) A X9 D: C7 W6 A/ ~* Ashall be taken as less than 30 kHz. The working voltage to determine minimum creepage3 r' j9 D9 Z0 M- {3 t( U
distances is the voltage measured after the ignition of the lamp. |
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