|
楼主 |
发表于 2021-8-13 10:08
|
显示全部楼层
本帖最后由 jansle_happy 于 2021-8-13 10:09 编辑
4 W& W, m& d7 l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。
1 i9 S: x U1 c5 aH.8.1.10 ACCESSIBLE PARTS shall not be considered as HAZARDOUS LIVE PARTS if separated from the supply by PROTECTIVE IMPEDANCE.
F0 S; S5 P- M6 Y' u1 S# k1 EH.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;% ]& s4 J1 l' T; L2 T! S
– 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);/ Q% N6 M z% U
– for voltages over 42,4 V (peak value) and up to and including 450 V (peak value), the capacitance shall; Q/ j0 X( b8 i8 f
not exceed 0,1 μF;
: G! I. N$ f- z9 ~– 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;5 a7 s$ u% W( p! G
– 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. C. j3 B/ Z# D6 L4 U8 w" _! w' b
Compliance is checked by measurement.
- J8 q9 M1 Q, [8 cVoltages and currents are measured between a single ACCESSIBLE PART (or any combination of such parts), `) t# j# T# X/ t% p8 f
and the protective earth conductor. Measurements shall be taken in normal supply configuration, and with9 Y& }2 R3 w( D
supply poles interchanged.$ r+ T5 @" L( a; c
The measuring circuit shall have a total impedance of (1 750 ± 250) W and be shunted by a capacitor such
! p) u; @% R) g; h0 g, ?that the time constant of the circuit is (225 ± 15) μs.
! j& M' Q+ g( T) F2 V! D) q9 VDetails of a suitable measuring circuit are shown in Figure E.1.' Y3 r" b' t" c. ^. h3 {
The measuring circuit shall have an accuracy of within 5 % for all frequencies in the range of 20 Hz to 5
! q6 m$ R% Z9 h/ MkHz. For frequencies above 5 kHz, alternative methods of measurement are required. |
|