[UL758]横截面积不够,电阻合格,是否符合要求?
section 5.3.4 有如下描述:The determination of conductor resistance described in 5.6.1 – 5.6.3 may be used as an alternative method for determining conductor cross-sectional area of AWG-sized conductors.
如果一条线,它的横截面积小于标准(tabel 5.1)规定的最小横截面积,但是电阻符合5.6的要求的话,这条线是合格的还是不合格的? 没有仔细看标准,但如果你的这条5.3.4的确来源于UL758最新版的话,是可以的.!因为UL62中也有关于此方面的描述,它是说"当导体截面积发生争议时,以直流电阻作为仲裁" 是的,是可以以电阻大小来确定是否合格。 是這樣的嗎?
UL軟線和電子線都可以以其導體電阻來判定是否合格嗎?
但是
5.3.1The size of a conductor shall not be less than indicated in Table 5.1 when measured in accordance with Conductor Diameter,Section200ofUL1581.
這個又怎麼解釋那? 在实际情况中,最终判断依据是电阻,而不是所谓的导体截面积,导体截面积只是一种结构的参考而己,电气参数判断不是用几何参数来衡量的。 用电阻大小来确定是否合格,可以接受. 下面是UL HK lab的回复:
If the conductor cross-sectional area cannot meet the AWG size but it could meet DC resistance requirement for that AWG size, we would consider the conductor with that AWG size per current standard UL 758.
Besides, the current standard for AWM is UL 758, Second Edition, with revision date January 11, 2008.When checking the requirement, the undated standard shall be used. 回复2如下:
If the conductor can meet the DC resistance requirement of that AWG size, the conductor can be considered as that AWG size even if the cross-sectional area cannot meet that AWG size. The determination of conductor resistance described in 5.6.1 – 5.6.3 may be used as an alternative method for determining conductor cross-sectional area of AWG-sized conductors. Conductors of Insulated Cables, IEC 60288, shall be used for metric-sized conductors, and shall be used as the referee method of determining conductor size.
之前从来没接触过这个标准。但是我看标准的这段话,总是认为前面一句讲的是两种方法都可用,两种要求都需要满足。后面说IEC 60288这个才是导体电阻是最终判断地依据。为什么要分开表述呢? 你要好好学习一下标准,导体电阻是合格的就行,不要管截面积.