Arc Fault Circuit Interrupters (AFCIs) are special types of electrical receptacles or outlets and circuit breakers designed to detect and respond to potentially dangerous electrical arcs in home branch wiring. AFCIs function by monitoring the electrical waveform and promptly opening (interrupting) the circuit they serve if they detect changes in the wave pattern that are characteristic of a dangerous arc. They also must be capable of distinguishing safe, normal arcs, such as those created when a switch is turned on or a plug is pulled from a receptacle, from arcs that can cause fires. An AFCI can detect, recognize, and respond to very small changes in wave pattern. Dedicated Computer Circuits and Additional Outlets. An isolated ground system provides a circuit pathway to your electrical system grounding bus by way of a dedicated conductor that is insulated from other conductive parts of the electrical system. Appliance Circuits.