In an effort to help home electrical appliance designers and manufacturers create better and more efficient products, the National Electrical Manufacturers Association (NEMA), Rosslyn, Va., has developed an educational guide providing information on the operating parameters of arc fault circuit interrupters (AFCIs). NEMA's guide gives designers insight to avoid potential conflict areas in the design of home products that may cause unwanted tripping in AFCIs. The guide covers design considerations for home electrical products including keeping current requirements within two fundamental boundaries — ground fault current and peak current — as well as other characteristics of arc faults that could trip an AFCI.
AFCIs are circuit breakers designed to detect dangerous electrical conditions that may lead to electrical fires. The device has been in the National Electrical Code (NEC) since 1999 which included an effective date of 2002. AFCIs were previously required to be installed during new home construction to protect the circuits that power bedrooms but expanded to existing dwelling units in the 2011 version. The 2008 version of the NEC expanded the requirement to include dining rooms, sun rooms, living rooms and other gathering areas in the home. Electrical safety experts believe expanding AFCI use could have a dramatic effect on the number of electrical fires and damage they cause annually, NEMA says. According to the NEMA fact sheet, the U.S. Consumer Product Safety Commission (CPSC) estimates that AFCIs could prevent more than 50 percent of the electrical fires that occur every year. In the United States, electrical problems cause a average of 50,900 home fires each year, resulting in more than 490 deaths, 1400 injuries and more than $1.3 billion in property damage. Arcing faults are a major cause of these fires.