The main function of a cable distribution box is to tap or transfer cables. Its specific functions are detailed as follows:
1、Cable Tapping Function: Using multiple small-cross-section cables on a relatively long line often leads to cable waste. Therefore, when supplying power to electrical loads, a main large-cross-section cable is usually used for outgoing lines. Then, when approaching the loads, a cable distribution box is used to split the main cable into several small-cross-section cables, which are connected to the loads. This wiring method is widely used for power supply to street lamps and small users in urban power grids.
2、Cable Transfer Function: On a relatively long line, if the length of a single cable cannot meet the line requirements, cable joints or cable transfer boxes must be used. Usually, intermediate cable joints are adopted for short distances. However, for long lines (based on experience, over 1000 meters), if there are multiple intermediate joints in the cable, a cable distribution box will be considered for transfer to ensure safety.
Cable distribution boxes are widely used outdoors. With technological progress, the number of cable distribution boxes equipped with switches is constantly increasing. Urban cables often adopt a dual-circuit power supply mode, so some people directly refer to distribution boxes with switches as outdoor ring main units (RMUs). However, most of these current RMUs cannot realize power distribution network automation, although some manufacturers have launched outdoor RMUs capable of distribution network automation. This has also blurred the boundary between cable distribution boxes and ring main units.
The editor from DAYA will continue to introduce more knowledge about high-voltage ring main units to help you gain a deeper understanding of cable distribution boxes. For more information, please follow DAYA Electric Group Co., Ltd. (https://www.hygraphics.com/). We will update content irregularly.