What are the installation requirements for cable earthing protection boxes and direct grounding boxes?

1.屏蔽一端直接接地，另一端通过护层保护接地：当线路长度在500---700m及以下时，屏蔽层可采用一端直接接地（电缆终端头位置接地），另一端通过护层保护器接地。

1. One end of the shield is grounded directly, the other end is grounded through protective layer: when the length of the line is 500-700m or less, the shield layer can be grounded directly at one end (grounded at the end of the cable), and the other end is grounded through protective layer.

2.屏蔽中点接地：当线路长度在1000----1400m时，须采用中点接地方式。（1）在线路的中间位置，将屏蔽直接接地，电缆两端终端头的屏蔽通过护层保护器接地。中间接地点一般需安装一个直通接头。（2）在线路中点安装一个绝缘接头，绝缘接头将电缆屏蔽断开，屏蔽两端分别通过护层保护器接地，两电缆终端屏蔽直接接地。

2. shielding neutral point grounding: when the line length is 1000----1400m, the neutral point grounding mode must be adopted. (1) In the middle position of the circuit, the shield is directly grounded, and the shield at both ends of the cable is grounded through the shield protector. The intermediate junction generally needs to install a through joint. (2) Install an insulated joint at the midpoint of the circuit. The insulated joint disconnects the cable shield, and the shielded ends are grounded through the protective layer protector respectively. The two cable terminals are shielded and grounded directly.

3.屏蔽层交叉互联电缆线路很长时（1000---1400m以上），可以采用屏蔽层交叉互联。这种方法是将线路分成长度相等的三小段或三的倍数段，蠕动泵 保定网站建设 保定网站制作 保定网络公司 保定办公家具 保定轻钢别墅 每小段之间装设绝缘接头，绝缘接头处三相屏蔽之间用同轴电缆，经交叉互联箱进行换位连接，交叉互联箱装有一组护层保护器，线路上每两组绝缘接头夹一组直通接头。