Difference between ring main cabinet and central cabinet

  The central cabinet is a kind of switch cabinet used by end users
It has full functions
It is the power receiving of 10kV system distribution room
The circuit breaker and metering unit can be removed
It is a handcart type structure
The protection of incoming line and feed is complete
The rated current is generally 630 ~ 3150A; Large volume,   The ring main unit is a kind of switch cabinet used in the ring network to connect two power supplies or parts
Most of them are vacuum or SF6 gas insulated load switches, and there are also gas producing load switches
The protection amount is small or no protection, but the rated current is generally 630 ~ 1250A
Most of the protection adopts fuse, and some products also have circuit breaker scheme, which is mainly used in the systems below 1000KVA transformer
The main function is to split two sections, with single function and small volume Because of their different uses, their structures and component selection are very different; There are many types of intermediate cabinets, which can be divided into incoming and outgoing switch cabinets, metering cabinets, transformer cabinets, used transformer cabinets, etc
the switches in the intermediate cabinets can be equipped with automatic protection devices
In case of an accident, the protection devices send signals to trip the switch action and cut off the power supply
VS1 vacuum circuit breakers are mostly selected in the cabinets; However, the ring main cabinet is mainly connected with the switch cabinet
Generally, there is no protection device in the ring main cabinet
In case of an accident, the fuse installed in the ring main cabinet is overheated and fused, cutting off the circuit, and selecting multiple switches to exchange high-voltage load switches in the user — Fuse combination apparatus, or six sulfur load switch; The ring main unit has a single function, that is, it is used to connect different power supply parts
Generally, it cannot be used to realize the control, protection and measurement of specific electrical equipment; If you really need these functions, you should select the central cabinet In the power supply and distribution system, the high-voltage power supply meter should be given priority, rather than the low-voltage measurement; When there is no way to install metering at the high-voltage side, the low-voltage metering mode can be considered; At this time, the low-voltage metering cabinet should be placed at the most “ Front ” Surface, that is, in front of the low-voltage incoming line and behind the transformer
However, the metering cabinet cannot be under the protection of the low-voltage incoming line cabinet
Therefore, in general, it should be under the protection of the high-voltage switch of the transformer, so the central cabinet should be selected
With the development of current power supply technology, the two types of cabinets have developed greatly, and the central cabinet is becoming smaller and smaller; The ring network cabinet is becoming more and more functional; But on the whole, the central cabinet is used for end-users and is a control equipment, but its price is relatively high; The ring main unit was originally designed to solve the problem of power supply leading out and introduction
Its function is relatively simple, but its structure is simple, its volume is small, and its price is relatively low
Recently, its function has been continuously expanded, especially its small volume is easy to be installed in “ Box transformer ” Internal, so it has a good development At present, the ring main cabinet is not only used as the contact switch cabinet, but also as the ring in and ring out switch cabinet, metering cabinet and Pt cabinet
At present, the ring main unit can not only be equipped with load switch — Fuse combinations can also be equipped with circuit breakers, such as domestic hxgn, Schneider SF6, Siemens 8dh, etc
, and microcomputer protection devices can be installed on the secondary protection
However, the circuit breaker installed in the ring main cabinet has load limits, and the limits of the ring main cabinet of each manufacturer are different
For example, if the protection capacity of high-voltage switch of Schneider RM6 ring main cabinet and transformer is greater than or equal to 2000kVA, circuit breaker +vip300 microcomputer protection must be adopted
The load of the incoming and outgoing lines of the central cabinet is not limited
Therefore, specifically speaking, whether the two can be interchanged, because the product functions and functions of various manufacturers are inconsistent, it is hard to say that the wide difference of their rated current should be considered in the design
Generally, if the total capacity exceeds 1250kva, the ring main unit is used Manufacturer of distribution cabinet: http://www
jtcele
com/  ;