A cable distribution box is a device used for tapping, branching, splicing, and circuit switching of cable lines, generally applied outdoors. The editor briefly introduces some technical elements of cable distribution boxes, and the content is for reference only. Cable distribution boxes are classified by their electrical composition into two types:
1. Ordinary Cable Distribution Boxes
They have no switching (circuit breaker) equipment, with only cable terminations and connecting accessories inside the cabinet. This type features a simple structure, small size, and limited functions. The incoming and outgoing lines can be connected directly, sharing the same potential, and are used primarily for tapping or branching connections. Electricians refer to "number of branches" as the sum of incoming and outgoing circuit counts. For example, a three-branch cable distribution box has three potential connection points per phase, allowing configurations such as one incoming and two outgoing lines, or two incoming and one outgoing line. The cabinet contains three phases (U, V, W) with identical circuit structures, which can be arranged together.
2. Advanced Cable Distribution Boxes
In addition to the accessories of ordinary distribution boxes, they are equipped with multiple switching (circuit breaker) devices. Their structural design is more complex, with a relatively larger volume, more internal connecting components, and higher manufacturing technical requirements. As a result, they are more expensive than ordinary ones in the market. Advanced distribution boxes not only fulfill the tapping and branching functions of ordinary types but also enable power circuit switching, control, and operation mode adjustment. The breakpoints of the switches separate the cable circuit into incoming and outgoing sides, which can have different potentials.
Switching equipment is relatively large. Typically, advanced distribution boxes have a height of 1.4–1.8 meters, a depth of 0.9–1.0 meters, and a length of approximately 1.0–2.4 meters (determined by the number of switching devices). The cabinet shape is similar to outdoor box-type transformers, with multiple movable doors on the shell—some designed for operating switching (circuit breaker) equipment, and others for the installation, maintenance, and inspection of cable connecting components.
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