Most busbars are not insulated along their length. Connections between lengths of busbar are soldered/welded for smaller sizes, but often. In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution, transmission, or switching substations. They are also used to connect high voltage equipment at. The function of the bus bar is direct and clear: to convey power (as high current and/or high voltage) from the source to the load with an acceptably low voltage drop and power loss. This means using solid bars of copper (sometimes aluminum) with a cross-section size that keeps resistive losses and. Voltage drop is well known to electrical engineers and is defined by Ohm's Law and the simplest of equations: V = I × R. The voltage drop is a function only of the current value and the path resistance and is independent of the rail voltage. A busbar is essentially a strip or bar of conductive metal, usually copper or aluminum. However, harsh operating conditions, material degradation, and improper maintenance can lead to insulator failures—jeopardizing safety and system reliability.