circuit breaker

circuit breaker (plural circuit breakers)

1. (electricity) An electrical switch capable of opening and closing an electrical circuit in all operating conditions, including fault situations.
   • 1961 November, “Talking of Trains: Derailment near Holmes Chapel”, in Trains Illustrated, page 652:

     From the evidence of witnesses and of the recorded passing times, including the time at which the circuit breakers were tripped when the wires were brought down, the train was travelling at a speed of not less than 70 m.p.h.

   • 2019 October, Roger Ford, “Power failure highlights specification confusion”, in Modern Railways, page 27:

     Typically traction packages monitor the supply frequency and if it strays outside pre-set limits open the circuit breaker between the pantograph and the transformer to shut off the power.

2. (electricity) More specifically, a circuit breaker that automatically breaks overcurrent conditions; a type of overcurrent protective device.
3. (finance) Synonym of trading curb
4. (chiefly Singapore) Quarantine measures intended to prevent spread of pandemics, especially COVID-19.
5. (programming) A design pattern used to detect failures and prevent them from constantly recurring.

• MCB (miniature circuit breaker)
• VCB (vacuum circuit breaker)

• disconnector
• fusebox
• movement control order (Malaysia)