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Report on High Energy Arcing Fault Experiments - Experimental Results from Open Box Enclosures



Gabriel Taylor, Anthony D. Putorti Jr., Scott Bareham, Christopher U. Brown, Wai Cheong Tam, Edward Hnetkovsky, Andre Thompson, Michael Selepak, Philip Deardorff, Kenneth Hamburger, Nicholas Melly, Kenneth Miller, Kenneth Armijo, Paul Clem, Alvaro Cruz-Cabrera, Byron Demosthenous, Austin Glover, Chris LaFleur, Raymond Martinez, James Taylor, Rana Weaver, Caroline Winters


This report documents an experimental program to investigate High Energy Arcing Fault (HEAF) phenomena. The experiments provide data to better characterize the arc to improve the prediction of arc energy emitted during a HEAF event. An open box allows for direct observation of the arc, jet, enclosure breach, material loss, and electrical properties. The experiments were performed at KEMA Labs located in Chalfont, Pennsylvania. The experimental design, setup, and execution were completed by staff from the U.S. Nuclear Regulatory Commission (NRC), the U.S. National Institute of Standards and Technology (NIST), Sandia National Laboratories (SNL) and KEMA Labs. In addition, representatives from the Electric Power Research Institute (EPRI) observed some of the experimental setup and execution. The HEAF experiments were performed between August 22, 2019 and September 18, 2019 on near-identical 51 cm (20 in) cubic metal boxes suspended from a Unistrut support structure. A three-phase arcing fault was initiated at the ends of the conductors oriented vertically and located at the center of the box. Either aluminum or copper was used for the conductors. The low voltage experiments used 1000 volts AC, while the medium voltage experiments used 6900 volts AC consistent with other recently completed experiments. Durations of the experiment ranged from 1 s to 5 s with fault currents ranging from 1 kA to 30 kA. Real-time electrical operating conditions, including voltage, current, and frequency, were measured during the experiments. Heat fluxes and incident energies were measured with plate thermometers, plate calorimeters, and slug calorimeters at various locations around the electrical enclosures. The experiments were documented with normal and high-speed videography, infrared imaging, and photography.
Technical Note (NIST TN) - 2198
Report Number


High Energy Arcing Fault, Arc Flash, Electrical Enclosure, Electric Arc, Fire Probabilistic Risk Assessment


Taylor, G. , Putorti Jr., A. , Bareham, S. , Brown, C. , Tam, W. , Hnetkovsky, E. , Thompson, A. , Selepak, M. , Deardorff, P. , Hamburger, K. , Melly, N. , Miller, K. , Armijo, K. , Clem, P. , Cruz-Cabrera, A. , Demosthenous, B. , Glover, A. , LaFleur, C. , Martinez, R. , Taylor, J. , Weaver, R. and Winters, C. (2021), Report on High Energy Arcing Fault Experiments - Experimental Results from Open Box Enclosures, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 26, 2024)


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Created December 29, 2021, Updated November 29, 2022