Building codes in many states are now requiring arc fault circuit interrupters, also known as AFCIs, to be installed in new construction. The units, which cost less than $35, detect arcing and sparking of electrical wires.
According to a Consumer Product Safety Commission study, residential fires caused by smoking, cooking and open flames have been drastically reduced in recent years, but electrical fires have stayed steady. In 2002, between 40,000 and 60,000 home fires in the United States were started by faulty electrical wires. In those fires, at least 490 people were killed.
AFCIs work like conventional circuit breakers by sensing thermal overloads and short circuits, but they also sense arcing wires within walls, something traditional circuit breakers do not do.
While AFCIs can be installed in non-residential construction, most building codes only require them in home construction, particularly in bedrooms. In 1999, the National Electric Code required that AFCI protection be installed on all 15- and 20-amp bedroom circuits in new construction beginning in 2002. But few contractors and electricians were willing to comply because early models of AFCIs were rumored to be ineffective and unreliable.
But according to the Ameritel Consulting group, more than 5 million AFCIs have been installed and no electrical fires have been reported in a home that has an AFCI circuit installed. There are currently 37 states that require the installation of AFCIs in new construction.
If used throughout the house, not just in bedrooms, the devices typically add about $300 to $400 to construction costs. Electricians can also install the units in completed homes.