March 1, 2008 12:00 PM
Most of us wouldn't mind a little extra cash now and then, and working overtime is usually a surefire way to earn additional money. For one journeyman electrician, however, those added hours proved to be too much of a good thing. The electrician, who had more than 20 years of experience, was fatigued from logging more than 80 hours of work in just five days. Assigned to work on an electrical circuit in an electrical vault that contained voltages in excess of 4,000V, he had intended to de-energize the circuit before proceeding, but de-energized the wrong circuit by mistake. When he went to the energized circuit to begin work, an electrical arc flash/blast occurred. Because the work was to be performed de-energized, the electrician was not wearing personal protective equipment, such as a face shield or insulating gloves. Therefore, he suffered burns to his face, neck, and hand, requiring hospitalization for approximately one week.
To prevent similar injuries, the following steps are recommended:
Accurately identify the equipment to be worked on and the energy isolating devices that will de-energize it.
Establish an “electrically safe work condition” whenever possible (i.e., de-energize it, lock it out, ground it, and test it).
Always test for the absence of voltage at the location of the work. When working with voltages exceeding 600V, attach a hot stick to a high-voltage detector to keep yourself a safe distance from a possible arc flash/blast.
Attach grounding cables/straps with the appropriate voltage and current ratings with a hot stick.
Work with your employer and ask them to schedule jobs to avoid excess overtime by employees.
Always use proper personal protective equipment.
Never wear rings, watches, or other jewelry when working with electricity.
Editor's Note: This electrical safety lesson is based on SHARP Report #85-4-2006, developed by the Safety & Health Assessment & Research for Prevention (SHARP) Program at the Washington State Department of Labor and Industries, Olympia, Wash.