本帖最后由 gmr24185 于 2016-8-8 11:44 编辑



最新UL676里对外部软线的要求：

一般要求：

10.3 Flexible cord that is immersed in water shall be suitable for:

a) Hard usage (such as Type SJW, SJTW, or STOW) and not smaller than 3.3 mm2 (12 AWG);

低压灯具要求：

11.4.5 Low voltage luminaires are permitted to use hard usage cords, per 10.3(a), not smaller than 0.20mm2 (24 AWG).



这里就疑惑了，是可以让电线厂将SJW, SJTW, or STOW线内导线制成min.24AWG的？印这应该不可以吧UL62 min.18AWG矛盾了。

请问有什么型号的Hard usage线可以做到低于18AWG呢？



【UL answer】

Yes – the power supply cord provided with a low voltage luminaire may be provide with individual internal conductors that are less than 18 AWG but no smaller than 24 AWG in size.The outer jacket insulation of the power supply cord must be rated for hard usage (Types SJW, SJTW, SJTOW, etc.) or extra hard usage(Types SOW, STW, STOW, etc.) per UL 62 requirements.

This assumes the luminaire is powered by an isolating low voltage power supply with ungrounded output (a two-conductor power source).The power supply cord can have more than two conductors provided that the insulation color of all individual conductors in the power supply cord are not green in color or green in color with one or more yellow stripes.We want to avoid the use of green color insulation for these low voltage supply conductors and/or luminaire signal conductors since green color insulation usually indicates it is for grounding or earthing connections.

Please also note, the Temperature Test would determine that the conductor size is rated for the amount of current it would carry during normal operation of the luminaire.