The National Association of Homebuilders just put out a bulletin called, “AFCIs: Do Homes Need More?“
In it, the NAHB argues against expanded requirements for arc fault circuit interrupters, as proposed by the National Electrical Code for its next edition to be published 2020.
AFCIs are meant to detect dangerous arcing events on the powerline, and turn off the relevant circuit(s) before an arc can cause a fire; however, there is not enough data to demonstrate that AFCIs — and especially more AFCIs — are effective in mitigating electrical fires, according to new research by the NAHB's group on Construction, Codes and Standards.
In addition, the proposed new mandates could add $500 to the cost of a home, unnerve homeowners with more nuisance trips, and generally mess with dimmers, computers, audio gear, motors, and pretty much any electronic thing that might generate noise that could look like hazardous arcs.
Upon learning about the NEC's proposal, an integrator told CE Pro: “Any Lutron dealer can relate. Arc fault is no fan of electronic dimming.
AFCIs were first required in the 2002 electrical code for bedrooms only. The 2008 edition added family rooms, dining and living rooms, libraries and rec rooms, closets and hallways. In 2014, the NEC added kitches and laundries.
The 2008 edition of the code expanded the mandate from just bedrooms, which had been required since 2002, to include family rooms, dining and living rooms, libraries, recreation rooms, closets and hallways. Only bathrooms, unfinished basements, garages and outdoors outlets are not required to have AFCI protection.
“We often hear that adding more AFCI coverage to dwellings ‘just makes sense’ based on the information presented in the 1990s leading to the initial 2002 mandate,” says NAHB senior program manager Dan Buuck in a letter to fellow members of the panel considering the amendments. “We are also asked to trust that AFCI technology is effective in protecting against certain arcing events, but we don’t have the data to back that up. In fact, it hasn’t lived up to expectations.”
Meanwhile, since the 2002 AFCI mandates, we have seen many improvements in home safety through other means. For example, the NEC requires electrical wires not to run less than 1 1/4 inches from the front edge of the framing members or be protected with a steel plate or other means, dramatically reducing the chance of wires getting hit by nails or screws.
Other provisions for wiring supports and bushings further decrease the risks of electrical fires.
In addition, the NAHB says manufacturers might be fighting for more sympathetic NEC provisions. One supplier apparently proposed reducing the tough standards for AFCI testing, allowing manufacturers to re-test their products if at first they don't succeed. The proposed change was not approved by the committee. Even so, acccording to Buuck, “it highlights the direction the manufacturers would like to see the standard go. This also enforces what we know, that a branch circuit protected by an AFCI device can still be subject to arcing.”
Between the scant evidence of AFCI's success, and the newer standards for safe wiring practics,” the NAHB argues.