Arc-Flash Risk in Low-Voltage Single-Phase Power Distribution: Improving Confidence in Arc-Flash and Electric Shock Equipment Labeling

National Fire Protection Association 70E and Canadian Standards Association Z462 require a qualified person to perform an electrical hazard assessment—including arc flash risk—for activities involving exposed, energized conductors or when interaction based on a work task could create an abnormal arcing fault. IEEE 1584-2018 “Guide for Performing Arc-Flash Hazard Calculations” documents the commonly accepted method for calculating arc-flash incident energy at an assumed working distance and the arc-flash boundary distance, for 208-V ac to 15k-V ac three-phase electrical equipment. While IEEE 1584 covers three-phase systems in detail, neither of the 2002 or 2018 editions provide modeling methods for single-phase systems. Single-phase 230-V and split phase 120/240-V ac power are the standard for residential and light commercial distribution around the world, and single-phase electrical equipment is common in industry. This article describes single-phase arc-flash experimental work conducted in 2020 as part of doctoral study and underpinning a dissertation. The principal investigator’s (PI’s) goal was to improve confidence in arc-flash and electric shock equipment labeling practices in support of his role as an industrial plant chief electrical engineer. The experimental hypothesis was: There is an available system energy threshold below which arc-flash incident energy would be low (less than 1.2 cal/cm²).