|
|
正确认案件 4.6mm, 且现在所有的认证单位都接受这种算法(TUV, UL, NEMKE, ITS都接受的),并且从标准出发,也是有根据,是正确的。4 W; i1 I' e0 {
重点: 请不要忘记表格2K, “PEAK WORKING VOLTAGE a”, 在峰值电压有备注一个小“a”, 对应到这个表格下面的备注,就是“a If the PEAK WORKING VOLTAGE exceeds the peak value of the AC MAINS SUPPLY voltage, see 2.10.3.3 b) regarding additional CLEARANCES.
! R# t! p1 _$ u
# Y+ h. Z- H: u# `# P+ d借上面兄弟的标准描述:* S2 ?# ]) C& q1 ?' e
For an AC MAINS SUPPLY not exceeding 300 V r.m.s. (420 V peak):
* R$ {9 y: J* Y# h, W0 ^a) if the PEAK WORKING VOLTAGE does not exceed the peak value of the AC MAINS SUPPLY/ p* F0 R+ e1 I' Q4 r* }0 X. i
voltage, minimum CLEARANCES are determined from Table 2K;+ y4 w: E( d7 k8 g0 J. A% V( t
b) if the PEAK WORKING VOLTAGE exceeds the peak value of the AC MAINS SUPPLY voltage,+ Z- R0 _6 J% B% N- L7 j) Q' f
the minimum CLEARANCE is the sum of the following two values:$ d+ |6 U! A+ `( s2 N4 v) f
• the minimum CLEARANCE from Table 2K; and" ^& v( n3 P4 `% k! T( y
• the appropriate additional CLEARANCE from Table 2L.
8 [/ }# j4 V" J& f% A
5 t: X4 g4 \& v0 `故我们通过确认 Upeak=612V, 根据表格2K (420V) ,要求4.0 mm, 然后再根据2L(612V), 再增加0.6 mm.
# ]6 \- z/ c9 i& s# Y TPEAK WORKING VOLTAGE a,请不要忘记表格2K, 在峰值电压有备注一个小“a”, 对应到这个表格下面的备注,就是“a If the PEAK WORKING VOLTAGE exceeds the peak value of the AC MAINS SUPPLY voltage, see 2.10.3.3 b) regarding additional CLEARANCES.”,所以说,最终还是用表格2K加上2L的距离,就等于最终的距离要求。故距离要求应该是 4.6 mm.$ p" q) @' P4 a6 O" {- R
2 E8 K7 ?) a% A% {* X$ \! N4 t问题已经明了,但有一个疑问是标准表格2K中提到的线性插入法,说是可以用,但基本目前的认证单位不会去用,且在标准第一版中是“3) For WORKING VOLTAGES between 2 800 V peak or d.c. and 42 000 V peak or d.c., linear interpolation is permitted between the nearest two points, the calculated spacing being rounded up to the next higher 0,1 mm increment.”,有一点不一样。 |
|