How does an arc flash happen?

Arc flashes are often catastrophic and result in serious injuries, even fatalities, and severe property damages. It is important to understand how and when an arc flash occurs, so you can work to avoid them.

An arc flash, or flashover, is an intense light and amount of heat that is produced from an arc fault. Arc faults are an example of electrical explosions caused by a low-impedance connection going through the air and to the ground. The release of electrical energy from an arc fault is what’s considered an arc flash. During an arc flash, an electrical arc will travel either from one conductor to another or to ground through the air. An arc flash is more likely to occur when work is being performed on live or damaged equipment.

Arc flashes occur quickly and will end once the circuit is broken. Although arc flashes don’t usually last longer than ten seconds but can cause a great deal of damage. The heat produced from an arc flash can melt metal, cause a fire, and the blast can easily break windows, bend metal, or splinter wood. Arc flashes result in temperatures upwards of 35,000°F and create a last strong enough to knock people over and collapse lungs.