Arc Flash Accidents Explained

By R.W. Hurst, The Electricity Forum

Arc flash accidents occur when a phenomenom known as "arc flash" explodes from energized electrical equipment without warning, injuring anyone in close proximity to the event. Arc Flash happens when the electrical current passes between two energized electrodes through ionized gases and vapors. The electrical energy supplied to the arc is converted into other forms of explosive energy. This results in incredible heat, explosive noise, expansion of the surrounding atmosphere due to rapid heating, and the subsequent melting/vaporization of arc electrodes and metal components.

What causes arc flash? It occurs when the insulation between the conductive components can no longer withstand the applied voltage.

Arc flash is primarily found in circuits of 208 and higher voltages in commercial and industrial facilities. Protection from arc flash is commonly referred to as a "personnel safety issue".

The number of arc flash accidents that have occurred has prompted many facilities to re-evaluate their electrical safety programs and their lockout procedures in the workplace.

A comprehensive electrical safety program will help protect employees from arc flash accidents and the resulting injuries: shock, burn and other personal injuries associated with arc flash accidents. Often, energized work is being performed without ensuring that an electrically safe work condition exists or that exposed employees or contractors are using the right personnel protective equipment (clothing , face protection, and tools) for the hazards.

What do you do when you can’t turn the power off? Do you expose your employees or contractors to unsafe conditions? Do you expose yourself or your company to liability? What is needed/required when your employees or a contractor work on energized systems?

Related Articles

Content Community Connection

ELECTRICITY TODAY | Advertisements