There are a few things no utility worker wants to experience—arc flash is one of them. The phenomenon is described as a sudden, bright, blinding light and heat that occurs as a result of rapid release of energy between two bus bars. The amount of energy released can be realized from the fact that air, which is normally an insulator, becomes a conductor.
The current responsible for producing an arc flash is known as arc fault current and is less than the bolted fault current putting it outside the bounds of circuit breakers’ normal range of operation. Unless specific devices have been installed to limit and handle arc fault conditions, they will not operate and thus leave the system in a hazardous state. Therefore, any worker in the vicinity of two faulty bus bars can become prone to fatal hazards.
As much as 80% of all electrical injuries are burns resulting from an arc-flash and ignition of flammable clothing. Fire-resistant clothing is an excellent way to protect engineers and technicians from such hazards. Knowledge of the following topics can ensure safety.
Arc flashes are prone to explosions. When current leaves its normal path (bus bars and travels through air) this means the surrounding air has been ionized. The underlying reasons may include dust, corrosion or any other element but the situation may reach to a tipping point involving an explosion. Thus, the NFPA70E standard has recommended FR protective clothing for all such environments where such an incident may occur.
While the danger of radiant heat is enough to put a worker’s life in jeopardy, the peril caused by an arc flash’s pressure wave blast is much more problematic. A high-amperage arc can produce forces as much as 1,000 pounds, enough to throw a person head over heels, resulting in countless impact injuries due to chemicals or dangerous equipment nearby. Furthermore, any nearby metallic particles can melt and make their way into a victim’s skin due to the sheer force, making matters even worse.
All these reasons solidify the importance of protective clothing for avoiding any damage caused by Arc Flash Faults, preventing any short-term or long-term sufferings. Examples of such clothing include:
In conclusion, with the recent advancements in protective wear technology, it would be extremely dangerous to neglect these resources. Proper clothing is a way to protect engineers and technicians from hazards, and should be utlized in all relivant situations.
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