户外灯具的接地形式

Grounding Forms of Outdoor Lightings

户外灯具的接地形式主要有TN系统和TT系统。通过对两种接地系统接地故障的分析计算,得出两种接地形式应用的条件和具体的接地措施。建议无论采用那种接地形式,均在灯具处设30 m A剩余电流保护作为主保护。对于不能在灯具处设剩余电流保护的场所,需要根据情况对灯具采用遮拦或外护物防护、双重或加强绝缘、特低电压供电等措施,这样才能最大限度地保障人体接触到户外灯具时的安全。

There are two major categories in the grounding forms of outdoor lightings（ such as streetlamps）. One is TN system,and the other is TT system. According to the analysis of two kinds of grounding systems. The applied conditions and the specific measures of the two grounding forms were obtained. The residual current operated protective device（ RCD）as main protection was set up for TN system or TT system. In some places which can＇t set up the RCD in the lamps,the measures were taken against lamps according to actual situation,such as protective barrier,enclosure protection,double or reinforced insulation,extra-low voltage. It can ensure the maximum safety when people touch the outdoor lamps.