Arc Flash Facts

WHAT IS ARC FLASH

An Arc Flash is very simply, an electrical short circuit through air. Whether it occurs from phase to ground or phase to phase doesn't matter. What does matter is that enough energy is present to perpetuate the arc. Lightning is an example of arc flash as is an electric arc welding machine. The difference between them is that lightning discharges itself in a very short period of time whereas an arc welding machine sustains the arc indefinitely. Either way, you don't want to get too near either of them. Arc flashes, like lightning, can cause electrical equipment to vaporize, resulting in an arc-plasma fireball. Temperatures may exceed 35,000° F (the surface of the sun is 9000° F). These high temperatures also cause rapid heating of surrounding air and extreme pressures joining together to produce the arc blast. The arc blast will further vaporize electrical equipment including solid copper conductors which will expand up to 67,000 times their original volume. The result of this violent event is usually destruction of the equipment involved, fire, and severe injury or death to any people who are unfortunate enough to be nearby.