Editing Circuit breaker (section)

{{Short description|Automatic circuit protection device}}
{{For-multi|the stock market term|Trading curb||Circuit breaker (disambiguation)}}
{{Infobox electronic component
 | component         = Circuit breaker
 | photo             = Jtecul.jpg
 | caption           = A two-pole miniature circuit breaker
 | invented          =
 | first_produces    =
 | symbol            = [[File:BreakerSymbols.svg]]
}}
[[File:AEG Circuit breaker type ME 800 (1).JPG|thumb|An air circuit breaker for low-voltage (less than 1,000 volt) power distribution switchgear]]
[[File: Four 1 pole circuit breakers fitted in a meter box.jpg|thumb|Four one-pole miniature circuit breakers]]
{{Electrical wiring sidebar}}

A '''circuit breaker''' is an electrical safety device designed to protect an [[Electrical network|electrical circuit]] from damage caused by current in excess of that which the equipment can safely carry ([[overcurrent]]). Its basic function is to interrupt current flow to protect equipment and to prevent [[fire]]. Unlike a [[fuse (electrical)|fuse]], which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.  

Circuit breakers are commonly installed in [[distribution board]]s.  Apart from its safety purpose, a circuit breaker is also often used as a main [[switch]] to manually disconnect ("rack out") and connect ("rack in") electrical power to a whole electrical sub-network.<ref>[https://safe-t-rack.com/frequently-asked-questions/ Frequently Asked Questions] at the [https://safe-t-rack.com/ Safe-T-Rack] company website. Accessed on 2024-07-28.</ref>

Circuit breakers are made in varying current ratings, from devices that protect low-current circuits or individual household appliances, to [[switchgear]] designed to protect [[high voltage|high-voltage]] circuits feeding an entire city. Any device which protects against excessive current by automatically removing power from a faulty system, such as a circuit breaker or [[fuse (electrical)|fuse]], can be referred to as an ''over-current protection device'' (''OCPD'').