A circuit breaker interrupts current flow in a line, transformer, or other equipment. It performs this function either when problems occur or when isolating equipment for maintenance or system switching. Circuit breakers are triggered to open or close through the protective relaying equipment operated by control switches and SCADA. Unlike fuses, circuit breakers can open and close repeatedly. The Circuit Breakers and Disconnects training course explains basic circuit breaker functions. it identifies different types of circuit breakers and their relaying and protection. This online course is part of the System Operations training series.