This guide will describe the different types of busbar failures, analyze reasons for these failures, present different means by which to diagnose, and identify some proven methods for preventing busbar failure. switchgear busbar sizing decisions should start from voltage class, fault level, and installation environment. Protection, interlocks, and maintenance access are often as important as the nameplate rating. Clear interface data reduces site rework between transformer, switchgear, breaker, RMU, and. Busbar protection (BBP): Protection intended to detect and operate to clear faults on a busbar. This generates both thermal stress (I²t heating) and mechanical stress (electrodynamic forces between conductors).