Filed under: Electrical, Fire Protection, Workplace Safety
I usually try to kick off my blog posts with an at least somewhat comical life observation, personal experience or childhood memory, but today I’m going to put all things quirky aside, and instead blog in all seriousness. Today, we’re talking about arc flash, an area in which I’m very grateful to have to no firsthand experience. In case you’re not too familiar with arc flash, it’s basically an industrial-strength electrical short that causes voltage from one conductor to spontaneously “arc” through the air to another exposed conductor. This arcing action can result in an extreme electrical explosion called an arc blast, which has the power to gravely injure, or even kill, anyone who happens to be nearby.
The explosion can generate a pressure wave that packs thousands of pounds per square inch, as well as temperatures up to 35,000°F. Force and temperatures of this magnitude can mean broken bones, collapsed lungs, ruptured eardrums, concussions, extensive third degree burns, and even damaged eyesight – and that’s if you’re lucky and it doesn’t just kill you on the spot. Arc blast can easily become personal tragedy, and there are electrical workers who face the risk of it every day.
Thanks to the National Fire Protection Agency (NFPA) and OSHA, electrical workers are now required to wear a range of Personal Protective Equipment (PPE) and flame retardant (FR) clothing to decrease their risk of injury should an arc blast occur in an area in which they’re working. Standard items of arc flash clothing include FR shirts, pants, and coveralls, arc flash hoods, face shields, safety goggle, ear protection, insulating rubber and leather gloves, and dielectric footwear made of rubber and/or leather. But while most arc flash PPE is intended to be worn, there’s one protective measure that you don’t actually put on: the arc protection blanket.
Arc protection blankets are generally made of heavy-duty canvas, and are intended to create a barrier between the arc explosion and the worker. Depending on the room or vault that the work is taking place in, arc protection blankets can either be suspended in various ways, or hung up against a wall. They’re particularly good for work in underground vaults, where they can be arranged like a makeshift funnel, to direct blast energy up and out of the chamber. Arc blast blankets not only have the ability to direct blast flow, but are also able to absorb impact and contain flames to a certain degree. And while they may not be completely foolproof (nothing is, when it comes to arc flash), when used in conjunction with regular arc flash PPE, they can leave you a lot better off than you’d be if you hadn’t used one.