By BUILDER Magazine Staff. Arc faults, dangerous electrical arcs caused by damaged wiring, cause many house fires. Beginning this year, the National Electric Code will require the installation of arc-fault circuit interrupters or AFCIs in bedroom circuits. That may just be the beginning. Last year, Vermont began requiring that AFCIs protect the entire house; other states will likely follow. Electrical device manufacturer Cutler-Hammer figured that where ground fault, or GFCI protection is also required, it made sense to combine the two types of protection in one device. Its new AFCI/GFCI circuit breaker ( is the first such breaker to be certified by Underwriters Laboratories (UL). It's available in 15- and 20-amp one- and two-pole units.