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circuit breaker
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Circuit breaker
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Key People:
Joseph Slepian
Related Topics:
electromagnet
relay
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Circuit breaker
Circuit breaker Circuit breakers in a meter box.

circuit breaker

electrical device
Also known as: contactor
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
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History

circuit breaker, automatic switch in an electric circuit. Its function is similar to that of a fuseā€”to open the circuit if abnormal current conditions occur, usually overloadsā€”but it is not destroyed in operation and can be closed again. The simplest circuit breakers are operated by a solenoid that is activated by an excessive increase in current flow. Small circuit breakers are widely used in place of fuses to protect electrical systems in homes.

This article was most recently revised and updated by Amy Tikkanen.