Arc flash is a dangerous risk among those in the power industry. Arc flash is an electrical breakdown of the resistance of air that results in an electric arc, which can occur where there is sufficient voltage in an electrical system and a path to ground or lower voltage.
Arc flashes can severely, even fatally, injure switchgear operators and bystanders, resulting in financial loss from medical costs, increased insurance costs, and turbine worksite downtime. AETI says studies show that 35% of arc flash incidents have occured when bystanders near or above the vent had no idea of the danger. And 65% of the incidents occurred with an operator working on the system, so the operator and bystanders near or above the vent both had an idea of the possible danger. But because an explosive arc flash travels at the speed of light, and once started it is not stopped by arc resistant methods, the practice has been to vent the arc flash explosion away from the operator via ductwork. However, when a space is confined, the explosion is often vented directly into the path of bystanders.
Both AETI and Schweitzer Engineering Laboratories offer products to help reduce arc-flash energy.