A circuit breaker is an automatic device for stopping the flow of current in an electric circuit as a safety measure. Its basic function is to interrupt current flow after a fault is detected. This week we will be taking a look at arc faults and ground faults and the dual function circuit breakers that combine GFCI (ground fault circuit interrupters) and AFCI (arc fault circuit interrupters), protecting against both arc faults and ground faults. By combining these two devices into one solution there is both a cost savings and installation and maintenance becomes more convenient.
Arc Fault – According to the National Electric Manufacturers Association, “Unlike a standard circuit breaker detecting overloads and short circuits, an AFCI utilizes advanced electronic technology to “sense” the different arcing conditions. While there are different technologies employed to measure arcs by the various AFCI manufacturers, the end result is the same, detecting parallel arcs (line to line, line to neutral and line to ground) and/or series arcs (arcing in series with one of the conductors).” The function of the AFCI is to protect the branch circuit wiring from dangerous arcing faults that could initiate an electrical fire.
Ground Fault – According to the National Electrical Code, a “ground fault” is a conducting connection (whether intentional or accidental) between an electric conductor and any conducting material that is grounded or that may become grounded. Electricity always wants to find a path to the ground. In a ground fault, electricity has found a path to ground but it is a path the electricity was never intended to be on, such as through a person’s body. Because of this potential for shock, GFCI protection is used to protect human life. A ground fault circuit interrupter (GFCI) can help prevent electrocution. If a person’s body starts to receive a shock, the GFCI senses this and cuts off the power before he/she can get injured.
Combination AFCI and GFCI – The 2014 National Electrical Code (NEC) now requires both Arc Fault and Ground Fault protection on kitchen and laundry circuits. Before the release of Dual Function Circuit Breakers, the only option to comply with this code was to pair an AFCI circuit breaker with a GFCI receptacle. The Dual Function Circuit Breaker combines GFCI and AFCI, protecting against both Arc Faults and Ground Faults.