This protective device monitors the electrical waveform for the specific signature of an electrical arc. If it senses sputtering current caused by loose connections, damaged wire insulation, or crushed cords, it trips the circuit. Unlike standard breakers that only trip on thermal overloads or direct short circuits, this unit looks for low-current arcing that can ignite building materials.
I had to swap the standard breaker for an arc-fault circuit interrupter to pass the bedroom inspection.
Nuisance tripping is the main complaint with AFCIs, often caused by the brush motors in older vacuum cleaners or power tools.
Also heard as
- AFCI
- Arc-fault breaker
Related terms
Circuit breaker
An automatic, resettable switch that protects an electrical circuit from damage caused by excess current.
Fuse
A sacrificial safety device that melts to break an electrical circuit when too much current flows.
Tub
Empty panel enclosure, the steel back box that goes in at rough-in before the interior and cover arrive.