what is a busbar

A busbar is a metallic strip or bar used for local high current power distribution in electric power distribution systems. They are typically housed inside switchgear, panel boards, and busway enclosures. Busbars are produced in a variety of shapes, including flat strips, solid bars and rods, and are typically composed of copper, brass or aluminium as solid or hollow tubes. Some shapes allow heat to dissipate more efficiently due to their high surface area to cross-sectional area ratio. Busbars must be sufficiently rigid to support their own weight, forces imposed by mechanical vibration, accumulated precipitation in outdoor exposures, thermal expansion from temperature changes induced by ohmic heating and ambient temperature variations, and magnetic forces induced by large currents. Flexible bus bars, typically a sandwich of thin conductor layers, were developed to address these concerns. Busbars may be connected to each other and used in any number of configurations, ranging from vertical risers to bars within a distribution panel, or part of an industrial process. They are often used in industrial applications, where they are installed in electrical panels or switchgear panels.