Arc-fault circuit interrupter: Difference between revisions

Revision as of 00:30, 15 August 2021

Revision as of 23:26, 30 August 2021

Line 4:

An '''arc-fault circuit interrupter''' ('''AFCI''') or '''arc-fault detection device''' ('''AFDD''')<ref>{{cite web |title=Do you know an Arc Fault Detection Device (AFDD) can prevent from an electrical fire? |url=https://blog.schneider-electric.com/power-management-metering-monitoring-power-quality/2013/07/03/do-you-know-an-arc-fault-detection-device-afdd-can-prevent-from-an-electrical-fire/ |publisher=Schneider Electric}}</ref> is a [[circuit breaker]] that breaks the circuit when it detects the [[electric arcs]] that are a signature of loose connections in home wiring. Loose connections, which can develop over time, can sometimes become hot enough to ignite house fires. An AFCI selectively distinguishes between a harmless arc (incidental to normal operation of switches, plugs, and brushed motors), and 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 outlet]]s in residential bedrooms by the electrical codes of [[Canada]] and the [[United States]] since the beginning of the 21st century; the U.S.US ''[[National Electrical Code]]'' has required them to protect most residential outlets since 2014,<ref>2014 NEC(210.12)</ref> and the ''[[Canadian Electrical Code]]'' has since 2015.<ref>{{cite book |date=2015 |title=C22.1-15—Canadian Electrical Code, Part I: Safety Standard for Electrical Installations |publisher=Canadian Standards Association |edition=23rd |isbn=978-1-77139-718-6 |page=Rules 24–724(f) & (g) |no-pp=y}}</ref> In parts of the world using 230 V, where the higher voltage implies lower currents, specifically Western Europe and the UK, adoption is slower, and their use is optional, except in high risk cases.

In the US, arc faults are one of the leading causes for residential electrical fires.<ref>{{cite journal|title=New Technology for Preventing Residential Electrical Fires: Arc-Fault Circuit Interrupters (AFCIs)|work=Fire Technology|volume=36|issue=3|publisher=Kluwer Academic Publishers|date=Aug 2000|pages=145–162|url=http://www.cpsc.gov//PageFiles/108737/AFCIFireTechnology.pdf|doi=10.1023/A:1015410726786|first=Douglas A.|last=Lee|first2=Andrew M.|last2=Trotta|first3=William H.|last3=King|issn=0015-2684|access-date=Feb 26, 2013}}</ref> 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.<ref>Ault, Singh, and Smith, "1996 Residential Fire Loss Estimates", October 1998, U.S. Consumer Product Safety Commission, Directorate for Epidemiology and Health Sciences.</ref>

Line 38:

AFCIs are also known to be sensitive (false tripping) to the presence of radio frequency energy, especially within the so-called ''[[high frequency]]'' (HF) spectrum (3-30&nbsp;MHz), which includes legitimate [[Shortwave radio|shortwave broadcasting]], over-the-horizon aircraft and marine communications, [[amateur radio]], and [[citizens band radio]] operations. Sensitivities and mitigation have been known since 2013.<ref>{{cite web|url=http://www.arrl.org/news/arrl-helps-manufacturer-to-resolve-arc-fault-circuit-interrupter-rfi-problems |title=ARRL Helps Manufacturer to Resolve Arc Fault Circuit Interrupter RFI Problems |website=Arrl.org |date=2013-11-19 |access-date=2017-03-28}}</ref>

AFCI circuit breakers include a standard inverse-time circuit breaker but provide no specific protection against ''"glowing''" connections (also known as a [[high resistance connection]]), high line voltages, or low line voltages.

An AFCI does not detect high line voltage duecaused toby an open neutral in a [[multiwire branch circuit]]. A multiwire branch circuit hasuses both energized wires of a 120-240 V [[split phase]] service. If the neutral is broken along the return path to the circuit breaker panel, devices connected from a 120&nbsp;V leg to the neutral may experience excess voltage, up to twice normal.

AFCIs do not detect low line voltage. Low line voltage can cause [[electromechanical relay]]s to repeatedly turn off and on, or "chatter". If current is flowing through the load contacts, it causes arcing across the contacts as they open. The arcing can oxidize, pit, and melt the contacts. This process can increase the contact resistance, superheat the relay, and lead to fires. Power fault circuit interrupters are designed to prevent fires from low voltage across loads.{{citation needed|date=November 2017}}

==Interference with power line networking==