Proper training is an important part of any occupation, but it's especially critical to workers in the electrical profession. A journeyman electrician and his helper learned this lesson firsthand while installing a 3-phase run of wire between an existing circuit breaker panel and a new piece of machinery.

During the installation, the journeyman electrician attempted to replace a missing bolt from a breaker mount on an energized 480V bus bar. While trying to screw the bolt into place, he lost control of it. Either the bolt or mount (or both) then came in contact with another phase in the circuit breaker panel, resulting in an arc flash. Although the electrician was wearing protective insulating gloves, he did not use safety glasses, shields, or any other protective equipment. In addition to temporarily losing his eyesight, the electrician received first- and second-degree burns to his head, face, and forearm as a result of the accident.

A short time later, the helper, who had no formal electrical training, was demonstrating to the facility owner what had happened when a second electrical arc flash occurred at the breaker panel, the cause of which is not known. The helper was not wearing any personal protective equipment and received second-degree burns to his head, face, neck, arm, and hand. Furthermore, the nylon jacket he was wearing melted to his skin. The journeyman electrician was hospitalized for one day, while the helper required multiple hospital visits for treatment of his burns.

To prevent injuries such as these, the following actions are recommended:

Electrical systems should be worked on in a de-energized state.

  • Discuss with the site manager whether the required work can be performed de-energized. This often can be accomplished through pre-planning and scheduling.

  • Isolate and lockout energy sources.

  • Ensure that stored energy doesn't exist, and apply appropriate grounding if necessary.

  • Use properly rated voltage testers to verify the absence of voltage at each energy point. This should only be done by a qualified person.

If work must be performed energized, follow all requirements in NFPA 70E.

  • All electrical companies should have a meaningful energized work policy.

  • Only qualified and well-trained individuals should perform energized work.

  • Plan and review the job carefully. Review all possible energy sources and identify potential hazards and prevention methods prior to starting the job.

  • Wear appropriate personal protective equipment rated for the job. Never wear clothing made of nylon, acetate, polyester, or rayon.

Electrical apprentices and other electricians are the only people who should assist an electrician in the field.

Editor's Note: This electrical safety lesson is based on SHARP Report #85-1-2006, developed by the Safety & Health Assessment & Research for Prevention (SHARP) Program at the Washington State Department of Labor and Industries, Olympia, Wash.