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老师说的很对,不过A1里面对这块作了适度修正,写得更合理了,主要还是要根据两端的工作电压来判定。+ Z" j) m# E: |
When fitting Y capacitors across barriers, the dielectric strength requirement must be# {$ v5 l7 c4 r7 f1 r! ~
considered. For example, for voltages in the range of 212 V peak to 354 V peak, two MEANS; Y4 t+ f- s5 {; ?% O- l5 ^
OF PATIENT PROTECTION are required to be tested at 4 000 V a.c. This would then require the
1 V" o) H! ]% F# e' Iuse of Y1 capacitors. Two Y2 capacitors in series would not withstand this voltage as they are) o P( l" K$ ], h
rated at 1 500 V a.c. each. For voltages below 212 V peak, two Y2 capacitors would suffice as# J ]; M/ r$ s/ j
the dielectric strength requirement is 3 000 V a.c.$ ?0 l: G" ^8 n1 x. o
/ w1 f4 Z0 Z" m# \
A Y capacitor (Y1 or Y2 only) complying with IEC 60384-14 is considered equivalent to one; j5 a$ Q4 j. U6 @
MEANS OF PATIENT PROTECTION. Where two capacitors are used in series, they shall be
8 P6 x6 K" B1 I7 O& r, W* t0 Oidentical in type (either both Y1 or both Y2) and shall have the same NOMINAL capacitance.. ?! O$ V r" A. b- x, [! p
The capacitor(s) shall meet the dielectric strength for the type of protection for which they are
! u6 h1 T1 D" h3 c, v ]being used (i.e. one or two MEANS OF PATIENT PROTECTION).
, O9 K" a4 R. p- R: H' u2 g0 \' ~: N* \7 w
Where the working voltage across a barrier forming a MEANS OF PATIENT PROTECTION is less
J1 Q6 L O2 @+ W+ O# K1 athan 42,4 V peak a.c. or 60 V d.c., a single Y1 capacitor is acceptable for two MEANS OF
1 h# _% Q/ b# _4 M6 x7 F fPATIENT PROTECTION. |
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