Arc Flash Hazard Incident Energy Calculations a Historical Perspective and Comparative Study of the Standards: IEEE 1584 and NFPA 70E

The exposure to hazards associated with electrical arcing phenomena, while working on energized equipment is a topic of significant interest to industrial plant personnel. This paper provides an overview of the current arc flash standards, focusing on the methods used to calculate incident energy levels in a system. A thorough sensitivity analysis of the arc flash hazard incident energy calculations currently adopted by the IEEE 1584 standard leads to some possible conservative simplification of the equations. These simple equations could be used for a quick "first-cut" assessment of the incident energy levels present in a system. A case study, using data from a typical petrochemical application, provides a comparison of the NFPA 70E and IEEE 1584 arc flash incident energy equations and the results obtained using the proposed simplified calculations.