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引用第2楼roy517于2007-11-06 12:02发表的 :5 L# W7 f- j. Z, i0 _7 ^
为什么呢?能说明原因吗?麻烦了! ( y4 F/ c# \* Z2 s7 c) e
UL13108 W! \' p8 S6 `; w: [. \
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14.2.2 The maximum voltages which may be accessible in accordance with 14.2.1(a) are:
# l9 q+ I! i3 s$ ua) 42.4 V peak for sinusoidal or nonsinusoidal AC;% G) D# u1 a4 H5 S* o t% ?7 H
b) 60 V for continuous DC;3 C6 q9 B. X9 r! V B7 {4 P# ^
c) 24.8 V peak for DC interrupted at a rate of 200 Hz or less with approximately 50 percent duty cycle; and) N7 _0 M* B1 \. E7 l) ?
d) As indicated in Figure 14.3 for combinations of AC and DC.
7 g3 ]+ o' u# O( IFor the purpose of this requirement, initial transients lasting less than 200 milliseconds may be ignored. Since short term peak voltage is of interest during tests involving a fault, voltages are to be monitored by using a storage oscilloscope for the first two seconds after any fault is introduced.
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"Since short term peak voltage is of interest during tests involving a fault," |
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