In an electric power system, switchgear is the amalgamation of electrical disconnects circuit breakers, fuses or switches used for controlling, protecting and isolating electrical equipment. Switchgears are used both to de-energize tools for allowing work to be done and to clear faults downstream. This kind of equipment is straight linked to the dependability of the electricity supply.
The very initial central power station used was an easy open knife switch; which was mounted on insulating panels of asbestos or marble. Power levels and voltages swiftly escalated, making opening physically operated switches too risky for anything other than isolation of a de-energized circuit. Oil-filled tool permitted arc energy to be contained and carefully controlled. By the early in 20th century, a Medium Voltage Switchgear line up would be a metal enclosed structure with electrically functional switching elements, utilizing oil circuit breakers. Nowadays, oil-filled equipment has mostly been replaced by air-blast, SF6 equipment or vacuum, or letting large currents and power levels to be securely controlled by an automatic equipment integrating protection, digital controls, communications and metering.