Technical term in computing and electrical engineering; refers to a device that automatically interrupts an electric circuit to prevent damage.
The circuit breaker in the server room tripped.
Shorter, more common term for a circuit breaker in everyday contexts; 電気回路ブレーカー is a longer, more explicit technical compound.
Compound of 電気回路 (electric circuit) and ブレーカー (breaker), a loanword from English.