What Are the Electrical Components in the Switchgear?

Switchgear is a complete set of power distribution equipment assembled from primary and secondary equipment according to a certain line scheme, which is used to implement control and protection for lines and equipment, divided into fixed and trolley type, and can be divided into high-voltage switchgear (fixed and trolley type) and low-voltage switchgear (fixed and drawer type) according to the voltage level of incoming and outgoing lines. The structure of the switchgear is largely similar, mainly divided into busbar room, circuit breaker room, secondary control room (instrumentation room), feeder room, and each room is generally separated by steel plates.

Internal components include busbar (busbar), circuit breaker, conventional relay, integrated relay protection device, metering instrument, isolation knife, indicator, grounding knife, etc.

Divided from the application point of view

(1) Incoming cabinet 

Also called receiving cabinet, is used to receive electrical energy from the grid (from the incoming line to the bus bar), generally installed with circuit breakers, CT, PT, isolation knife and other components.

(2)Outlet cabinet

Also called feeder cabinet or distribution cabinet, is used to distribute electrical energy equipment (from the busbar to each outlet), generally also installed with circuit breakers, CT, PT, isolation knife and other components.

(3) Busbar contact cabinet

Also called busbar breakout cabinet, is used to connect two sections of busbar equipment (from busbar to busbar), in the single busbar segmentation, double busbar system is often used busbar contact, to meet the user to choose different operating requirements or to ensure that the fault situation has the option to remove the load.

(4) PT cabinet

Voltage transformer cabinet, generally installed directly on the busbar to detect the busbar voltage and achieve the protection function. Mainly installed inside the voltage transformer PT, isolation knife, fuse and lightning arrester, etc.

(5) Isolation cabinet

It is used to isolate the two ends of the bus bar with or isolate the powered equipment and power supply equipment with, it can provide a visible end point to the operating personnel to facilitate maintenance and overhaul operations. Since the isolation cabinet does not have the ability to break and connect the load current, it is not possible to push or pull the handcart of the isolation cabinet in the case of closing the circuit breaker with it. In general applications, it is necessary to set the interlock between the auxiliary contact of the circuit breaker and the isolation trolley to prevent misoperation of the operating personnel.

XGN2 type modular high-voltage switchgear cabinet is applied to receive and distribute the electrical energy in three-phase AC power system with rated voltage 3, 6, 10KV and rated frequency 50HZ, especially for the frequently operated occasion. Its busbar system is a single busbar (which can derive the single busbar with bypass and double busbar structure). The switchgear cabinet is in line with the requirements of the National Standards GB3906 3-35KV AC Metal-enclosed Switchgear and the international Standard IEC298, also there are proposed "five anti" interlocking functions such as anti-breaking and closing by mistaken for circuit breaker, anti-breaking and closing disconnector switch with load, anti-breaking and closing grounding wire/switch with load, anti closing circuit breaker/disconnector switch with grounding wire/switch, anti entering charged interval by mistaken.