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仔细阅读62368下面条款/ F" I0 W$ f" t/ Y3 }
5.4.1.8 Determination of working voltage' \( N& U( ^) }# r- i
5.4.1.8.1 General
, K/ a% H: y7 j: p4 L3 ^. `In determining working voltages, all of the following requirements apply:
/ n L# p' H: i9 `1 w$ qa) unearthed accessible conductive parts are assumed to be earthed;
; R6 F, f0 I0 R ~9 S7 b, hb) if a transformer winding or other part is not connected to a circuit that establishes its$ M9 y6 x: x/ R# Y; u
potential relative to earth, the winding or other part are assumed to be earthed at a point by- M! W; v( F: V5 s2 p6 j3 U
which the highest working voltage is obtained;, ~1 e- q" @" {4 Y! [( p" j9 L
c) except as specified in 5.4.1.6, for insulation between two transformer windings, the highest6 T0 _7 m( T m, q0 d. _. J
voltage between any two points in the two windings is the working voltage, taking into
" M9 W. M$ S* y0 `( k8 p9 g' J& Baccount the voltages to which the input windings will be connected;
, p: T7 M- N+ Z( @2 o6 zd) except as specified in 5.4.1.6, for insulation between a transformer winding and another, \% ?7 L2 w Q1 }& X: h2 D
part, the highest voltage between any point on the winding and the other part is the working0 } E) ?2 I8 U8 d9 P
voltage;) C4 D5 }4 ^! R
# q1 Y5 X, w/ R. h" T4 H$ w& r7 m
e) where double insulation is used, the working voltage across the basic insulation is3 E" A7 h+ r+ c# G7 ~' z
determined by imagining a short-circuit across the supplementary insulation, and vice- v! H: U$ M% w
versa. For double insulation between transformer windings, the short-circuit is assumed# d- h4 ?; W+ m5 T2 H1 ]0 h# X
to take place at the point by which the highest working voltage is produced across the
b# d% L7 Q, T v2 a4 Q' ~- lother insulation;
9 _. V3 N; w' f4 f2 ?f) when the working voltage is determined by measurement, the input voltage supplied to the3 f* x! T8 n$ t3 |2 F
equipment shall be the rated voltage or the voltage within the rated voltage range that# i, }) z# O" y4 b
results in the highest measured value;- S& ?) Y; n9 j8 b$ U4 W, c# W
g) the working voltage between any point in the circuit supplied by the mains and
" a, e. Y$ B" [6 L9 j– any part connected to earth; and
% O, F" _5 O! N7 l7 {– any point in a circuit isolated from the mains,
3 J0 B. q6 \' |5 Rshall be taken as the greater of the following:) y! I, C" I/ ?! c0 r8 \- {
– the rated voltage or the upper voltage of the rated voltage range; and) i; E6 ~( }/ k' Z/ p
– the measured voltage;
$ g N! T# N2 i) |( \9 x |$ Rh) when determining the working voltage for an ES1 or ES2 external circuit, the normal
7 G, F9 T" ]6 S4 m$ uoperating voltages shall be taken into account. If the operating voltages are not known, the) f. t4 Q5 N( Y& u- m- A
working voltage shall be taken as the upper limits of ES1 or ES2 as applicable. Short4 R6 w' s, v9 q6 E% b
duration signals (such as telephone ringing) shall not be taken into account for determining/ A# t) p. N. j
working voltage;
" G Q; [- x' N, h' zi) for circuits generating starting pulses (for example, discharge lamps, see 5.4.1.7), the
5 N, L! N1 K! |: Q9 jworking voltage is the peak value of the pulses with the lamp connected but before the; f* m) W z3 E0 G R6 q2 B. R
lamp ignites. The frequency of the working voltage to determine the minimum clearance
8 O1 A/ r) I$ g: F; Hshall be taken as less than 30 kHz. The working voltage to determine minimum creepage" [9 ?) t" |9 O# d8 d2 j' }( a
distances is the voltage measured after the ignition of the lamp. |
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