Arc Detection Circuit Breaker

After having been slowly phased in over the past 3 nec code cycles these new arc fault breakers are now required on almost every 120v circuit in the finished space of the house.

Arc detection circuit breaker.

A conventional circuit breaker isn t sensitive enough to detect electricity arcing through the air while the arc is still too small to ignite a fire. Combination afci protection is required by the nec as of january 1 2020. Breaker afci and gfci protection. This series arc detection is beneficial to detect lower level arcing in both branch circuits and power supply cords.

When a nail punctures a wire behind the wall or a wire nut loosens and a small electrical current begins to build up heat. As long as this arc is sustained in between the contacts the current through the circuit breaker will not be interrupted finally as because the arc is itself a conductive path of electricity. What are arc fault detection devices. For total interruption of current the circuit breaker it is essential to quench the arc as quickly as possible.

They use microprocessor technology to analyse the waveform of the electricity being used to detect any unusual signatures which would signify an arc on the circuit. Arc fault circuit breaker afci breaker is the latest arc fault detection device its main function is to detect and identify dangerous earthing arc faults parallel arc faults and series arc faults and to drive the device operation that cut off current timely to avoid electrical fires. Afdds are protective devices installed in consumer units to provide protection from arc faults. An arc fault circuit breaker differs from a gfci in that it detects slow electrical leaks.

A slow leak typically occurs when wiring is compromised but not completely shorted i e. Afcis are designed to sense an arc which is an electrical leak caused when a hot wire touches a neutral or ground but doesn t trigger the circuit breaker. You may even recognize these arc fault circuit interrupter breakers with their visible test button in your circuit breaker panel. An arc fault circuit interrupter afci also known as an arc fault detection device afdd is a circuit breaker that breaks the circuit when it detects an electric arc in the circuit it protects to prevent electrical fires.