AFCI offers added protection from potentially hazardous arc-faults resulting from damage in branch circuit wiring as well as extensions to branches such as appliances and cord sets. By detecting hazardous arc-faults and responding by interrupting power, the AFCI helps reduce the likelihood of the home's electrical system being an ignition source of a fire.
Often unseen, arc-faults can occur anywhere in the home's electrical system including within walls, at loose electrical connections or within electrical cords accidently damaged by impinging furniture.
AFCIs are now required by the National Electrical Code® (NEC®) in many areas of the home including bedrooms, family rooms, dining rooms, living rooms, kitchens, sunrooms, hallways and similar rooms or areas. For information on what you need to do when adding an outlet to your home this video gives you a great understanding of how to install Arc fault protection for your home.
An Arc Fault Circuit Interrupter (AFCI) is an advanced circuit breaker that breaks the circuit when it detects a dangerous electric arc in the circuit it protects to prevent electrical fires. An AFCI selectively distinguishes between a harmless arc incidental to normal operation of switches, plugs, and brushed motors, versus a potentially dangerous arc that can occur, for example, in a lamp cord which has a broken conductor.
AFCI breakers have been required for circuits feeding electrical outlets in residential bedrooms by the electrical codes of Canada and the United States since the beginning of the 21st century; the US National Electrical Code has required them to protect most residential outlets since 2014,and the Canadian Electrical Code has since 2015.
Arc faults are one of the leading causes for residential electrical fires. Each year in the United States, over 40,000 fires are attributed to home electrical wiring. These fires result in over 350 deaths and over 1,400 injuries each year.
Conventional circuit breakers only respond to overloads and short circuits, so they do not protect against arcing conditions that produce erratic, and often reduced current. An AFCI is selective so that normal arcs do not cause it to trip. The AFCI circuitry continuously monitors the current and discriminates between normal and unwanted arcing conditions. Once detected, the AFCI opens its internal contacts, thus de-energizing the circuit and reducing the potential for a fire to occur.