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...

Over the last few decades, arc-fl ash hazards have been a significant concern for many electrical workers and employers. Many methods have been developed through the years to assess incident energy.
The most common is that of the IEEE 1584, Guide for Performing Arc-Flash Hazard Calculations. These equations have remained the same since the standard was first published in 2002. Based on the results of more than 1,800 tests, the 2018 edition of the guide provides new formulas that are both more accurate and more complex. These formulas also take more parameters into account now, including the conductor orientation at...