What is an Arc Flash?

An arc flash occurs when a large-scale fault condition or short circuit causes electricity to travel through the air. The electrical current leaves its intended path and travels from one conductor to another or to the ground. The movement of massive electrical currents rapidly vaporizes the conductive material and causes an explosion.

The arc flash is the light and heat from the explosion, and the arc blast is the pressure wave that follows. Arc flashes produce extremely high temperatures of up to 35,000 °F, which is roughly four times hotter than the surface of the sun. The pressure wave created by an arc fault can propel metal shrapnel at more than 700 miles per hour. The sound from the blast can reach 170 decibels, louder than a jet.

To learn more about Arc Flash Safety visit our OSHA Construction Arc Flash Safety Online Training web page.