1）电缆分接作用。在一条距离比较长的线路上有多根小面积电缆往往会造成电缆使用浪费，于是在出线到用电负荷中，往往使用主干大电缆出线，然后在接近负荷的时候，使用电缆分支箱将主干电缆分成若干小面积电缆，由小面积电缆接入负荷。这样的接线方式广泛用于城市电网中的路灯等供电、小用户供电。 1) cable tapping. In a relatively long distance lines with a plurality of small area cable tends to cause the cable waste, so in advance to load, often use the trunk cable outlet, then when close to the load, the use of cable branch box will be divided into several small trunk cable cable, cable access by small area load. This connection is widely used in urban power grids, such as street lighting, power supply, small user power supply. 2）电缆转接作用。在一条比较长的线路上，电缆的长度无法满足线路的要求，那就必须使用电缆接头或者电缆转接箱，通常短距离时候采用电缆中间接头，但线路比较长的时候，根据经验在1000M以上的电缆线路上，如果电缆中间有多中间接头，为了确保安全，会在其中考虑电缆分支箱进行转接。 2) cable transfer function. In a long line, the length of the cable can not meet the requirements of the line, you must use the cable connector or cable connection box, usually a short distance when using cable joints, but when the line is long, according to the cable line in the above 1000M experience, if there are many joints between cables, in order to to ensure safety, in which considering the cable branch box switch. 电缆分支箱广泛用于户外，随着技术的进步，现在带开关的电缆分支箱也不断增加，而城市电缆往往都采用双回路供电方式，于是有人直接把带开关的分支箱称为户外环网柜，但目前这样的环网柜大部分无法实现配网自动化，不过已经厂家推出可以配网自动化的户外环网柜了。这也使得电缆分支箱和环网柜的界限开始模糊了。 Cable branch box is widely used in outdoor, with the progress of technology, now the cable branch box with switch is also increasing, while the city cable is often used in double loop power supply, so some people directly to the branch box with switch called outdoor RMU, but at present most of this ring network cabinet cannot realize distribution automation. But manufacturers launched outdoor ring network cabinet to the distribution automation. This also blurs the line between the cable box and the ring rack.