A section of a large switchgear panel, in this case, used to control on-board casino boat power generation. Oil-filled equipment allowed arc switchgear and protection pdf to be contained and safely controlled. By the early 20th century, a switchgear line-up would be a metal-enclosed structure with electrically operated switching elements, using oil circuit breakers.
The technology has been improved over time and can now be used with voltages up to 1,100 kV. The switchgear on the low-voltage side of the transformers may be located in a building, with medium-voltage circuit breakers for distribution circuits, along with metering, control, and protection equipment. One of the basic functions of switchgear is protection, which is interruption of short-circuit and overload fault currents while maintaining service to unaffected circuits. Switchgear also provides isolation of circuits from power supplies. Switchgear is also used to enhance system availability by allowing more than one source to feed a load. The first models were very primitive: all components were simply fixed to a wall.
Later they were mounted on wooden panels. This led to a further improvement, because the switching and measuring devices could be attached to the front, while the wiring was on the back. Switchgear for lower voltages may be entirely enclosed within a building. Gas-insulated switchgear saves space compared with air-insulated equipment, although the equipment cost is higher. Oil insulated switchgear presents an oil spill hazard. Switches may be manually operated or have motor drives to allow for remote control.