Function and principle of ring main cabinet

Ring main cabinet is very common in our life. What is the role of ring main cabinet? What is the working principle of ring main cabinet?

Function of ring main cabinet

The ring main cabinet is an electrical equipment in which a group of high-voltage switchgear is installed in a steel plate metal cabinet or made into an assembled interval ring main power supply unit. The core part adopts load switch and fuse, which has the advantages of simple structure, small volume, low price, improving power supply parameters and performance and power supply safety. It is widely used in power distribution stations and box type substations of load centers such as urban residential quarters, high-rise buildings, large public buildings, factories and enterprises.

Working principle of ring main cabinet

In order to improve the reliability of power supply, users can obtain power from two directions, and usually connect the power supply network into a ring. This power supply mode is called ring network power supply for short. In industrial and mining enterprises, residential areas, ports, high-rise buildings and other AC 10kV power distribution systems, because the load capacity is not large, the high-voltage circuit is usually controlled by load switch or vacuum contactor, and is equipped with high-voltage fuse protection. The system usually uses ring network for power supply, and the high-voltage switchgear used is commonly called ring network cabinet. In addition to supplying power to the distribution station, the high-voltage bus of the ring main cabinet also passes through the through current of the ring power supply network (i.e., the current that supplies power to the adjacent distribution station through the bus of the distribution station). Therefore, the section of the high-voltage bus of the ring main cabinet shall be selected according to the sum of the load current of the distribution station and the through current of the ring network, so as to ensure that the high-voltage bus does not run under load during operation.

Application scope of ring main cabinet

It is applicable to 12kV and below three-phase AC 50Hz ring network power supply system or terminal power supply system, as well as box type substation. It can be widely used in the construction and transformation of urban power grid, and is applicable to the distribution system of industrial and mining enterprises, high-rise buildings, residential quarters, hospitals, schools, parks, etc.

Performance characteristics

Equipped with vacuum load switch and spring operating mechanism, the mechanism can be operated manually or electrically. The grounding switch and isolating switch are equipped with manual operating mechanism. The ring main cabinet has strong integrity, small volume, no combustion and explosion hazards, and has reliable five prevention functions.