Circuit Breaker

A switching device capable of making, carrying, and interrupting electrical currents under both normal operating conditions and short-circuit fault conditions. Unlike disconnect switches, circuit breakers can safely open and close under full load current and can interrupt fault currents of tens of kiloamperes. Circuit breakers receive trip signals from protective relays and must clear fault current within a few cycles (typically 3–5 cycles, or 50–83 ms at 60 Hz). They use SF₆ gas, vacuum, or oil as the arc-interrupting medium and are rated by voltage class, continuous current, and interrupting duty (kA symmetrical).

Ready to test yourself?

Practice this term with interactive flashcards

Explore more

All games · Transmission Planner · Docket Defender · Energy Persona quiz