Arc Flash Accidents |
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Arc flash accidents occur as a result of a phenomenom known as "arc flash". Arc Flash is a consequence of the passage of current between two
electrodes through ionized gases and vapors. The electrical
energy supplied to the arc is converted into other forms of
energy, resulting in intense thermal radiation, noise, explosive
expansion of surrounding air due to rapid heating, and
melting/vaporization of arc electrodes and metal components
in the vicinity of the arc. What causes this? An electric arc flash 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?
Photo Description: On May 23, 2005, a 48 year-old electrical foreman, with 15 years mining experience, was fatally injured on the surface of an underground gold operation. The victim was working near an energized high voltage conductor when apparently an arc flash occurred. (Photo coutesy U.S. Department of Labor.)
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