Arc Flash Analysis
An arc flash is usually caused by inadvertent contact between an energised conductor, such as a bus bar or wire. with another conductor or an earthed surface. When this occurs the resulting short circuit current will melt the conductors, ionise the air and create a conducting plasma firereball with temperatures in the core of the arc that can reach upwards of 20,000 °C. Severe injury and even death can not only occur to persons working on the electrical equipment but also to people located nearby. Arc Flash injury can include external burns to the skin, internal burns from inhaling hot gases and vaporised metal, hearing damage, eye damage such as blindness from the ultraviolet light of the flash as well as many other devastating injuries. Depending on the severity of the arc flash, an explosive force known as an arc blast may also occur, which can result in pressures of over 100 kPa, launching debris as shrapnel at speeds up to 300 m/s.
Survivors of such injuries may require extensive treatment and rehabilitation and the cost of these injuries can be extreme, physically, emotionally and financially. Although legislation requires businesses to perform risk assessments for all work activities, electric arc risk is often overlooked because most people are unsure how to assess and manage this hazard effectively.