UL1598,
11.3.8 An open hole in a box, such as a mounting-screw hole, shall have no dimension larger than 6.7mm (0.265 in), except that a pryout hole or slot may be provided in a knockout for 1 in or smaller trade size conduit, provided that the area of the hole or slot is no more than 26 mm2 (0.040 in2)
19.10 Surface ceiling temperature test apparatus
(2) The sides shall be 2 x 6 in trade size wooden members.
(3) The ends shall be 1 x 6 in trade size wooden members.
(4) The inside supports shall be 2 x 4 in trade size wooden members.作者: fasten 时间: 2008-8-8 16:14
trade size在这里是指的一种约定俗成的尺寸, 专门在市场上流通的一种尺寸. 它的表面意思是商业尺寸,销售尺寸或流通尺寸, 实际上隐含了具体是多大的尺寸. 具体多大为一个标准的trade size, 你可以参考:
Table 6.15.2.1
Dimensions for conduit openings
整流器为永久性安装,按照要求提供一个单螺纹接头,接头为出口标准长,足够使两个防松螺母和附件装配一起。
A ballast intended for permanent installation and provided with a single, threaded nipple meets the intent of the requirements when the nipple is a standard trade size long enough for two locknuts for assembly to a fixture enclosure.作者: 一直在学习 时间: 2008-8-12 11:56
我大致明白了,就相当于比例换算一样,对吗?
standard trade size是一个固定值吗? 还是每个行业有不同的trade size?作者: frankpeng 时间: 2008-8-12 16:35
引用第4楼一直在学习于2008-08-12 11:56发表的 :
我大致明白了,就相当于比例换算一样,对吗?
standard trade size是一个固定值吗? 还是每个行业有不同的trade size?
答:每个行业有不同的 standard trade size.作者: 一直在学习 时间: 2008-8-12 18:32
多谢相助