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本帖最后由 jansle_happy 于 2021-8-13 10:09 编辑
- N# j; q* I& S% J0 `& P大神看起来,应该不是说figure E只是个列子吧,看起来原文是前面描述了测试电路的特性,然后给出具体的图书如图E啊。: A2 J2 J! c! z l f: @4 a
H.8.1.10 ACCESSIBLE PARTS shall not be considered as HAZARDOUS LIVE PARTS if separated from the supply by PROTECTIVE IMPEDANCE.
3 T& @7 s( {) U$ r- z- ?3 IH.8.1.10.1 When PROTECTIVE IMPEDANCE is used, the current between the part or parts and either pole of the supply source shall not exceed 0,7 mA (peak value) a.c. or 2 mA d.c;
: M/ Q% ^8 X# B% a6 \( {– for frequencies exceeding 1 kHz, the limit of 0,7 mA (peak value) is multiplied by the value of the frequency in kHz but shall not exceed 70 mA (peak value);
8 C' L' b8 C6 M7 o' H" x– for voltages over 42,4 V (peak value) and up to and including 450 V (peak value), the capacitance shall& |! |) E2 t' F
not exceed 0,1 μF;7 F" M) D+ N; {; y& j5 R+ Z
– for voltages over 450 V (peak value) and up to and including 15 kV (peak value), the product of the capacitance in farads times the potential in volts shall not exceed 45 μC;/ P+ R7 j9 M% A) _* d+ f6 n
– for voltages over 15 kV (peak value), the product of the capacitance in farads times the square of the potential in volts shall not exceed 350 mJ.6 F$ @4 Q/ d- P3 ?# ~
Compliance is checked by measurement.
" ?& l5 P6 C% o: HVoltages and currents are measured between a single ACCESSIBLE PART (or any combination of such parts)- W$ d5 R7 M1 t. g" ^# @& x
and the protective earth conductor. Measurements shall be taken in normal supply configuration, and with
* K- W4 z2 Q% r) asupply poles interchanged.
% p" |: Z; M8 {: w7 F: sThe measuring circuit shall have a total impedance of (1 750 ± 250) W and be shunted by a capacitor such. r8 P# w2 Z% L/ f
that the time constant of the circuit is (225 ± 15) μs., N" c. i7 U( p$ c2 _7 j% g+ G$ K6 Y
Details of a suitable measuring circuit are shown in Figure E.1.
: R# A. A/ K- l4 o* V2 X1 eThe measuring circuit shall have an accuracy of within 5 % for all frequencies in the range of 20 Hz to 5
$ i1 M4 R* E- N' ? ZkHz. For frequencies above 5 kHz, alternative methods of measurement are required. |
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