In the first case study, an electrician was working on a circuit breaker panel that he thought was deenergized. After completing the work, the electrician was closing one of the enclosure doors when an arc flash occurred. Electric current from the energized panel moved through the air to the closed panel door. The rapid release of energy caused the panel door to fly open, hitting the worker and knocking him unconscious as the panel continued to arc.
Although the electrician believed that all power had been deenergized from the electrical panel, OSHA said this incident could have been prevented by voltage testing the electrical panel before starting work. Taking the time to perform a simple test can ensure workers’ safety.