CT: The circuit breaker is an absolutely essential device in the modern world and one of the most important safety mechanisms in your home. Whenever electrical wiring in a building has too much current flowing through it, these simple machines cut the power until somebody can fix the problem. Without circuit breakers (or the alternative, fuses), household electricity would be impractical because of the potential for fires and other mayhem resulting from simple wiring problems and equipment failures.
S: http://electronics.howstuffworks.com/circuit-breaker.htm (last access: 26 December 2014)
N: 1. circuit (n): late 14c., “a going around; a line going around,” from Old French circuit (14c.) “a circuit; a journey (around something),” from Latin circuitus “a going around,” from stem of circuire, circumire “go around,” from circum “round” + ire “to go”. Electrical sense is from 1746. Of judicial assignments, from 1570s; of venues for itinerant entertainers, from 1834. Circuit breaker is recorded from 1874. Related: Circuital.
breaker (adj): “heavy ocean wave,” 1680s, agent noun from break (v.). Related: Breakers.
2. Switch that protects electrical equipment from damage by opening a circuit whenever there is an excessive current.
3. It has contacts that open automatically, usually when an overload or short circuit causes an excessive current.
4. breaker; no-fuse breaker: terms officially approved by The Postal Mechanization Terminology Standardization Committee.
5. CB: Circuit designation for “circuit breaker”.
6. circuit breaker: term standardized by the CSA.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=circuit&searchmode=none; http://www.etymonline.com/index.php?allowed_in_frame=0&search=breaker&searchmode=none (last access: 26 December 2014). 2, 3, 4, 5 & 6. TERMIUM PLUS (last access: 26 December 2014).
SYN: CB, C/B, contact breaker (UK).
S: TERMIUM PLUS (last access: 26 December 2014)