When are they required?
An AFCI ( Arc Fault Circuit Interruptor ) is a device / circuit breaker used to detect series arcs. This device, when a series arc is detected, will trip the circuit and turn off the power source. A combination AFCI will detect both series and parallel arcs.
These AFCI breakers are required in all bedrooms, hallways, dining, living, and breakfast areas, as well as lighting circuits or other similar areas.
As of 2011 they are required by the NEC in all living areas on new construction projects, or total renovations. They protect the circuit and detect arching in early stages to prevent a fire. Generally your lighting/receptacles are protected with a AFCI circuit breaker, or device.
AFCI stands for arc fault circuit interrupter
This circuit breaker device senses arcs on a circuit and shuts it off before a fire begins.
These devices are required by code to be used for all plugging outlets in sleeping quarters/bedrooms.
An AFCI is an arc fault circuit interrupter. It is a breaker or receptacle designed to prevent fires. An arc occurs for various reasons…loose connections, frayed or knicked wires. When an arc occurs, the current in the circuit is not flowing through the circuit as it should. For example, if a hot conductor has been hit by a screw, the current will try to “jump” across the screw which can cause heat to build up and potentially cause a fire. AFCIs are designed to detect this and trip out, shutting the circuit off until the problem is fixed. According to the 2014 National Electric Code, AFCIs are required in all finished areas of homes except kitchens and bathrooms.
I’ve always thought of AFCI’s as if they were ears. They work by “listening” to the frequency that is emitted by electrical arcing as it jumps across a di-electric (air, rubber, plastic, insulation etc…). So when this arcing happens, the ‘ear’ hears it and trips the overcurrent protective device (i.e. a breaker or fuse) to prevent the heating and potential fire hazard that accompanies these types of arcing events.
An arc fault circuit interrupter is a breaker designed to prevent a fire. This breaker will detect an arc trip and shut the circuit off until the problem is corrected.