Although arc flash has been a concern amongst the electrical industry for many years, it is only relatively recently that standards by the IEEE have been established on calculating the amount of energy behind an arc flash event. However, these standards only apply to AC systems, where extensive testing and research have been performed. Although the NFPA has provided recommendations on how to calculate the incident energy for DC arc flash events, these have not become the defining standard like those seen for AC. One equation outlined in the NFPA70E, the Maximum Power Method, does provide engineers with a formula to calculate DC arc flash incident energy but as the NFPA states this can be quite conservative. However, the NFPA70E also mentions a Detailed Arcing Current and Energy Calculations Method which contains formulas proposed by various researchers who conducted their own DC arc flash testing but there is scarce info on how these methods compare to the Maximum Power Method. This paper will investigate the relative power of two of the formulas proposed in the alternate method, the results from Stokes/Oppenlander and the results from Paukert, over a variety of parameters that affect DC arcing power. These will then be compared to relative power of the Maximum Power Method, as well as the relative power of the AC equations formed from measurements. Although the results in this paper are not aiming to be a defining standard, the aim is to provide engineers with information on when one methodology is more suitable to use for a given set of certain parameters.

Arc flash is one of the two primary hazards encountered by workers near electrical equipment. Most applications where arc flash may be encountered are alternating current (AC) electrical systems. However, direct current (DC) electrical systems are becoming increasingly prevalent with industries implementing more renewable energy sources and energy storage devices. Little research has been performed with respect to arc flash hazards posed by DC electrical systems, particularly energy storage devices. Furthermore, current standards for performing arc flash calculations do not provide sufficient guidance when working in DC applications. IEEE 1584-2002 does not provide recommendations for DC electrical systems. NFPA 70E provides recommendations based on conservative theoretical models, which may result in excessive personal protective equipment (PPE). Arc flash calculations seek to quantify incident energy, which quantifies the amount of thermal energy that a worker may be exposed to at some working distance. This thesis assesses arc flash hazards within a substation backup battery system. In addition, empirical data collected via a series of tests utilizing retired station batteries is presented. Lastly, a predictive model for determining incident energy is proposed, based on collected data.