Circuit breakers and switchgear are among the most common, yet critical, components of an industrial electrical system. Circuit breakers are devices that interrupt or complete electrical circuits. They protect systems and equipment from the effects of excessive current, and they provide a way to switch power on and off and isolate circuits or equipment on which work is being performed. Switchgear is basically a self-contained, enclosed assembly of circuit breakers and auxiliary devices. Part of your responsibility involves keeping circuit breakers and switchgear working properly. So, it is important for you to have a good understanding of how circuit breakers work and the types of maintenance procedures that are typically performed on them.