Intelligent Power Today Magazine

IEEE Method Vs. the NFPA 70E Tables: Evaluating arc flash analysis methods

BY REZA TAJALI, Schneider Electric

Recent changes in workplace safety regulations have heightened the awareness of hazards associated with electrical arcs. The hazard level must be quantified and workers properly protected before entering proximity of exposed energized conductors. National Fire Protection Association’s (NFPA) standard 70E: “Standard for Electrical Safety in the Workplace” provides the guidelines for work involving electrical hazards and the selection of arc flash protective equipment.

In order to select the protective gear properly, one must have knowledge of the potential thermal energy of the electric...

While most discussions about arc flash involve the calculation methods and associated personal protective equipment (PPE), electricians have a number of ways to protect themselves and their gear, including arc-resistant equipment and remote actuation and racking systems that eliminate—rather than reduce—electrical arc-related dangers while providing quantifiable force and other preventive maintenance data that can help avoid future catastrophes.

Similar to any energy source, an electrical circuit is a ticking bomb. It is simply waiting for the right conditions to blow. A twisted pole, faulty interlock, and enough energy will turn an electrical firecracker into a mortal lightning strike. Moreover, what...