What is the relationship between backbone cables, branch cables and distribution cables

1. Contact: The backbone cable refers to the cable directly connected to the power supply; the branch cable refers to the cable that comes out of the distribution box and connects to the user or each workshop; the distribution cable refers to the cable that is electrically connected to the distribution box. Their function is to act as a bridge chain connecting the telecommunications room to each user client.

2. Difference: The number of backbone cables and distribution cables cannot be similar. The backbone cable should be one or two, the branch cable needs more than two, and the distribution cable should be more. Branch cables are divided into vertical branches and Horizontal branch. For vertical branches, they are mainly applicable to high-rise buildings. Generally, they are measured on site and divided according to the drawing, that is, the cross sectional area of cables is selected according to the load of each floor, the cable model is selected according to the fire resistance rating of the project, and the cable length is selected according to the distance between the low-voltage distribution cabinet and the highest floor of the branch; For Horizontal branch cable, the line selection basis is the same as that for vertical branch, but the length of Horizontal branch cable can be larger than the trunk line, but its sectional area should be smaller than the trunk line section. It should be noted that the vertical main line should be higher than the three section levels of the branch line.