Arc Flash. If you’re an industrial electrician or an electrical lineman you know what it is and how dangerous it can be, especially in terms of fire. For the rest of us there are articles like Let’s Blow It Up! Arc Flash Testing, which was recently posted on the Electrical Contractor website. The story sounded more interesting than it turned out to be; there is a long discussion of the mechanics of arc testing but no pics or video of things blowing up. Fortunately, there are plenty of videos on YouTube that show why you don’t want to be anywhere near an arc flash—be it from a short in a high-voltage panel, a mishap involving overhead power lines, or hitting a buried cable with an excavator.
The video below was produced by Westex, a Chicago company that makes flame-resistant fabric used in work clothing and safety gear. It includes a number of tests that show what happens to manikins wearing various types of clothing. The synthetics and cotton-poly blends do not fare well—they catch fire and burn.
I’ve seen this first-hand, not in the context of an electrical accident but when a mechanic using a torch to remove a frozen bolt on my truck accidentally hit the fuel line. Gasoline shot out, he and my truck caught on fire, and I ended up chasing him across the parking lot while trying to snuff out the flames with my jacket. It’s not just electricians who need to watch what they wear.