A Study on Arc Flash Incident Energy Reduction Methods Applicable to the Korea Electro-technical Code Based on a Review of International Standards

Arc flash is among the most hazardous electrical accidents in industrial power systems, instantaneously generating high-temperature plasma that causes severe worker injury and equipment damage. While NFPA 70E and IEEE 1584-2018 provide systematic risk assessment procedures, the Korean Electro-technical Code (KEC) has yet to establish criteria for incident energy (IE), arc flash boundary, and PPE requirements. This study analyzes arc flash causes based on NFPA 70E and IEEE 1584-2018, examining key parameters including short-circuit current, protective device clearing time, and working distance. The IEEE 1584-2018 model was applied together with the instantaneous trip time range specified in KS C IEC 60947-2 to compare incident energy under standard and high speed clearing conditions. Results show that reducing clearing time significantly decreases incident energy, bringing it below the second-degree burn threshold. Simulation verification confirmed that shorter clearing times lower the PPE category and substantially narrow the arc flash boundary. These findings demonstrate that optimizing protective device clearing time, even within the existing KEC framework, offers the most practical and effective approach to reducing incident energy, providing meaningful foundational data for future domestic risk assessment standards.