Do you realize that copper expands 67,000 times when it changes state from solid to vapor in an arc flash incident? This pressure wave can cause eardrum damage, concussions or consequential falls, and it can also damage surrounding equipment or tear protective clothing. This blast damage is sometimes forgotten when discussing arc flash.
There are two primary types of physical hazards from arc flash when working around electrical equipment: shock and burns. Most people can relate to an electrical shock from personal experience. When I was a child, I would receive a shock if I unplugged the household vacuum and accidentally touched the plug prongs. I didn’t get hurt, but wow! I respected the power of electricity after that. Obviously, the electrical systems that we design and work around have much higher voltages and current levels than my childhood home, so the risk for injury is far greater.
In recent years, electrical burns have received greater attention and emphasis from… continue reading