Hazards Associated With Neutral Conductors: A Case Study

Establishing an electrically safe work condition, as defined in article 120 of National Fire Protection Association (NFPA) 70E, is a common practice in the electrical industry to ensure that a system has been and will remain de-energized during work performed on equipment. The process includes steps to confirm that all sources of energy have been isolated, locks/tags have been installed, and all voltage potential has been verified to be zero prior to work commencing. This article examines a scenario where a previously undetected voltage hazard manifested itself while lifting/isolating neutral conductors in an electrically safe work condition. This hazard can go undetected through traditional methods to establish an electrically safe work condition; it can result in harmful and even fatal electrocution. This article examines the risk, provides common scenarios for when this danger could manifest, and provides mitigation methods through engineering and administrative controls.