Hands On Exercise Arc Flash Job Done Settings And

Short circuit arc in the distribution box

The arc between the circuit breaker contacts occurs due to the ionization of air, just as the air is ionized during a system short circuit. An arc is created by ionization of a gas (normally air) by means of an electric discharge between electrodes of different potential or phase angle, or between an electrode and earth. The term "arc discharge" is also common. Unlike simple short circuits that make solid contact, arc faults maintain a deadly air gap that superheats to plasma temperatures hotter than the sun's surface. In a residential setting, an arc flash usually produces little more than a brief flash of light before extinguishing itself harmlessly.