High-Voltage Arc Flash Assessment and Applications

This article explores the need for high-voltage arc flash (HVAF) assessment for utility workers who are exposed to the line to line voltages above 15 kV. The regulatory requirements will be discussed including OSHA, NESC, etc., to get an understanding of how utilities consider HVAF. Furthermore, the methods for evaluating HVAF, key driving factors, and rule of thumbs, and HVAF personal protective equipment will be discussed and compared in great detail to aid in the selection of a thermal incident energy evaluation method. The article includes an example application of HVAF assessment using various commercially available software. This example illustrates the importance of performing an HVAF assessment for utility applications and highlights the differences between thermal incident energy evaluation methods and how they can be conservatively applied for situations outside their intended application range.