Arc-fault circuit interrupters (AFCIs)
What are these? Are you required to have them? They are special types of electrical receptacles or outlets and circuit breakers a that detect and respond to potentially dangerous electrical arcs in home branch wiring.
AFCI’s monitor and detect changes in the wave pattern that are characteristic of a dangerous arc. They are capable of distinguishing safe, normal arcs, such as those created when a switch is turned on or a plug is pulled from a receptacle, from arcs that can cause fires.
The basic definition of an arc is when an electric current crosses an air gap from an energized component to a grounded component, it produces a glowing plasma discharge known as an arc. Example would be a bolt of lightening is a very large, powerful arc that crosses an atmospheric gap from an electrically charged cloud to the ground or another cloud. These arcs can cause fires.
These arcs can form when
- wires are improperly installed or
- when insulation becomes damaged
- damaged electrical cords by vacuum cleaners or trapped beneath furniture or doors.
- damage to wire insulation from aging
- damage from nails or screws driven through walls
- natural aging, kinking, impact or over-extension
- spillage of liquid
- loose connections in outlets, switches and light fixtures
Are AFCIs required?
Short answer is: depends on the building codes in a given jurisdiction
Are they a good idea?