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仔细阅读62368下面条款
! Z: w8 @) a4 N& ^8 @5 { m1 O% y5.4.1.8 Determination of working voltage
- R& `* J6 |' |8 o, Y5.4.1.8.1 General9 a `8 z1 b g( e7 I8 [! C
In determining working voltages, all of the following requirements apply:
: L' y) |' J3 F) D4 ^8 ca) unearthed accessible conductive parts are assumed to be earthed;! _: z: O; u1 a& V/ t* `, z
b) if a transformer winding or other part is not connected to a circuit that establishes its
: O5 e- {# b$ g3 V( y M, Q& B" z a2 Fpotential relative to earth, the winding or other part are assumed to be earthed at a point by
/ V6 E+ T- X- s# |* V2 o) zwhich the highest working voltage is obtained;
# P* h. j) H2 T. Hc) except as specified in 5.4.1.6, for insulation between two transformer windings, the highest
1 w, H1 f/ T9 \: ^6 ?voltage between any two points in the two windings is the working voltage, taking into
* @9 {' e$ t4 C( t" ~1 ]& q$ \account the voltages to which the input windings will be connected;
2 T1 u0 \6 X5 S/ E$ Bd) except as specified in 5.4.1.6, for insulation between a transformer winding and another
3 v# }8 j; N$ D" K+ n' `part, the highest voltage between any point on the winding and the other part is the working
1 _. z" V" r5 o y8 Zvoltage;: ~9 @, l/ J! j; t4 W, o
2 ?8 [# i( d2 |7 e2 X3 X, ~e) where double insulation is used, the working voltage across the basic insulation is5 i( m) G8 y7 |( h) X
determined by imagining a short-circuit across the supplementary insulation, and vice
8 Z* s6 q+ i6 f1 D+ l: Hversa. For double insulation between transformer windings, the short-circuit is assumed
Q! s. Q5 \" t7 [, {to take place at the point by which the highest working voltage is produced across the
1 w% W7 e3 H1 pother insulation;
* b, W+ S' j1 a" af) when the working voltage is determined by measurement, the input voltage supplied to the
L! a/ ] y- W4 k6 Y6 j6 X' S* Nequipment shall be the rated voltage or the voltage within the rated voltage range that) G+ `; n6 m9 S
results in the highest measured value;6 g9 c3 w: N( ~/ w9 u
g) the working voltage between any point in the circuit supplied by the mains and7 `" E' _, i3 M2 L; m7 n2 I* F
– any part connected to earth; and, Q1 i# F0 B- C9 w' y; W
– any point in a circuit isolated from the mains,
5 p" _2 l( { j4 |) Wshall be taken as the greater of the following:
. q; m; `5 _4 w4 n; s3 b% R– the rated voltage or the upper voltage of the rated voltage range; and
; c3 h( z5 m9 X( W* } w5 M– the measured voltage;
8 M# ~- f) N9 ^h) when determining the working voltage for an ES1 or ES2 external circuit, the normal2 j# W# _8 H+ S
operating voltages shall be taken into account. If the operating voltages are not known, the9 \" ? G6 ]5 A$ n
working voltage shall be taken as the upper limits of ES1 or ES2 as applicable. Short
, {6 E: Y7 A" |( @duration signals (such as telephone ringing) shall not be taken into account for determining! B4 b2 s& e0 {
working voltage;
* i8 R, ]# B5 x7 m1 ei) for circuits generating starting pulses (for example, discharge lamps, see 5.4.1.7), the. R0 c; A' H r" e& @3 y. m
working voltage is the peak value of the pulses with the lamp connected but before the
( o7 m% V0 h6 ], `0 qlamp ignites. The frequency of the working voltage to determine the minimum clearance
) N7 x3 g9 i- R, O5 K, l% N# ishall be taken as less than 30 kHz. The working voltage to determine minimum creepage
( G" c" O# w$ @ [5 {3 edistances is the voltage measured after the ignition of the lamp. |
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