|
本帖最后由 jansle_happy 于 2021-8-13 10:09 编辑
% C: Z4 T, v$ Q0 O" B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。# z4 b5 ^8 u& ^, S3 W& H
H.8.1.10 ACCESSIBLE PARTS shall not be considered as HAZARDOUS LIVE PARTS if separated from the supply by PROTECTIVE IMPEDANCE.' W, v; J; ]: Y
H.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;$ a3 H! J" A% D1 Y
– 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);5 O8 p2 Q3 b0 Z+ U: f9 Y% p
– for voltages over 42,4 V (peak value) and up to and including 450 V (peak value), the capacitance shall
" B+ o' l9 V2 m& k p* t1 mnot exceed 0,1 μF;4 J8 f# B& g1 ]; a4 t& K1 e
– 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;. D% d" ?8 l# P- D, F* D
– 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., a2 Z L" v' }* O8 H$ w8 a3 r
Compliance is checked by measurement.3 c- {/ p( F1 c. ]4 d7 p9 {
Voltages and currents are measured between a single ACCESSIBLE PART (or any combination of such parts). G2 f2 r2 e: x+ m! v
and the protective earth conductor. Measurements shall be taken in normal supply configuration, and with
, O: t' `5 y T0 A- ^supply poles interchanged.
* J! e+ q. E( e, [1 f) iThe measuring circuit shall have a total impedance of (1 750 ± 250) W and be shunted by a capacitor such9 W, F9 i' E. |
that the time constant of the circuit is (225 ± 15) μs.1 O3 k: b7 Z/ D( P1 z% Q
Details of a suitable measuring circuit are shown in Figure E.1.
0 R7 }+ l h) GThe measuring circuit shall have an accuracy of within 5 % for all frequencies in the range of 20 Hz to 5
# {2 P$ y, \2 x6 `- I$ MkHz. For frequencies above 5 kHz, alternative methods of measurement are required. |
|