Permanent Magnet Ring Network cabinets(Ring Main Unit) is a group of electrical equipment (high-voltage switchgear) installed in metal or non-metallic insulating cabinets or made into a assembling spacer ring network power supply unit, its core part of the use of load switches and fuses, with simple structure, small size, low price, Can improve the power supply parameters and performance as well as power supply safety and other advantages. It is widely used in urban residential quarters, high-rise buildings, large public buildings, factory enterprises and other load center distribution stations and box-type substations.
Ring cabinet appears not a long time, but has been widely used, mainly due to the newly developed industrial enterprises and institutions of the building, from the point of view of power supply and distribution, to medium, small capacity for most of its distribution transformers generally not more than 1250KVA, long-term stable power supply, high-voltage switches do not operate frequently. For this type of user, the performance of the ring cabinet is not the most perfect, but it is sufficient to be competent. With large-scale urban construction, a large number of large high-rise buildings sprang up, power distribution is often located downstairs, according to fire requirements, power distribution equipment must be "oil-free", according to the reasonable use of construction area, power distribution equipment should be "miniaturized", so ring cabinets or vacuum circuit breakers, dry-type transformers, The dry-type transformer entered the building. The ring cabinet structure is simple, the operation is reliable and safe, the maintenance quantity is very small, the running cost is low, compared with the switchgear equipped with the circuit breaker, the advantage is very prominent. Ring cabinet requires load switch with higher performance and smaller volume, the new load switch came into being, which in turn led to the technical progress of the ring cabinet, today's ring cabinet not only excellent performance and serialization, which also expanded the use of ring cabinets.
Switching cabinet (switch cabinet) is an electrical equipment, switch cabinet outside the first into the cabinet main switch, and then into the sub-control switch, each division according to its needs set. Such as instrumentation, automatic control, motor magnetic switch, a variety of AC contactors, and some also set up high-pressure room and low-pressure room switchgear, with high-voltage busbar, such as power plants, and some have to protect the main equipment of the low-cycle reduction. The main role of switchgear (switchgear) is to open and close, control and protect electrical equipment in the process of power generation, transmission, distribution and power conversion. The components in the switchgear are mainly circuit breakers, isolation switches, load switches, operating mechanism, transformers and various protective devices. There are many classification methods of switchgear, such as the installation method of circuit breaker can be divided into open switchgear and fixed switchgear, or according to the different structure of the cabinet, can be divided into open switchgear, metal closed switchgear, and metal closed armored switchgear, according to different voltage levels can be divided into high-voltage switchgear, Medium voltage switchgear and low-voltage switchgear and so on. Mainly applicable to power plants, substations, petrochemicals, metallurgical steel rolling, light industrial textiles, factories and mining enterprises and residential areas, high-rise buildings and other different occasions.
1, to prevent the load division, combined with the isolation switch. (Circuit breaker, load switch, contactor closing state can not operate the isolation switch.) ）

2, to prevent false points, mistakenly combined circuit breakers, load switches, contactors. (Only the operation instruction corresponds to the operating equipment to operate the ** device)

3. Prevent the grounding switch from closing the circuit breaker and load switch when it is in a closed position. (Only if the grounding switch is in the sub-gate state, can the isolation switch or handcart to enter the working position, can operate the circuit breaker, split-load switch closure)

4, to prevent the grounding switch is mistakenly combined when charged. (Only in the circuit breaker sub-gate state, can operate the isolation switch or handcart can be returned from the working position to the test position, in order to close the grounding switch)

5, to prevent the wrong into the live room. (Only when the compartment is not charged can it open the door into the compartment) the necessity of the joint operation of Electric two anti-error locking and microcomputer anti-error atresia