The DC Arc Flash Test Database provides a central location for accessing experimental data from published dc arc flash studies and test programs. It is intended to make existing results easier to find, compare, and reuse for model development, verification, and future testing. The database will continue to expand as additional reports, publications, and test data are identified and processed.
Reconstructed Data and Uncertainty
Numerical test results are often published as figures rather than a series of raw data points, which is useful for presenting overall test behavior but makes quantitative analysis difficult. To combat this, voltage and current time series data are extracted from published figures using WebPlotDigitizer when necessary. This process introduces reconstruction uncertainty from manual axis calibration, finite figure resolution, and trace thickness. Small shifts of only a few pixels during calibration can changed the mapped current, voltage or time values, while a thick waveform trace may span a range of possible values at a single timestep rather than identify one exact value. As a result, reconstructed values may differ slightly from the original measured voltage and current.
For questions, feedback, or to submit data, please contact dmrose@sandia.gov.
Publication | DOI: 10.1109/ESW52258.2024.10752762 | Test Data
Recommended Citation:
W. Cantor, L. Gordon and S. Marri, “NFPA 70E Proposed DC Arc Flash Updated Guidance,” 2024 IEEE IAS Electrical Safety Workshop (ESW), Tucson, AZ, USA, 2024, pp. 1-7, doi: 10.1109/ESW52258.2024.10752762.
Abstract:
The Standard for Electrical Safety in the Workplace (NFPA 70E) is the industry standard for electrical worker safety. In 2012 DC arc flash guidance was added to the document. There have been updates since then, but most arc flash calculations still rely on the maximum power method that has been unchanged since 2012. The maximum power method is overly conservative, and in most cases, overestimates the true hazard. Additionally, some users are multiplying the result from the maximum power method by three for anything in a cabinet even though this specific multiplier has been removed from the standard in the 2018 version. This results in an even more conservative calculation. The main issue with updating the guidance has been the lack of test data for dc arc flash. AC arc flash has been well characterized by comprehensive testing and modelling resulting in very specific guidance in IEEE 1584. However, over the past several years, several organizations have conducted dc arc flash testing and much of this has been reported. Additionally, there have been efforts, including by a co-author, to better characterize the risk through modeling using this test data. This paper will propose changes to the next revision of NPFA 70E which the authors plan on turning into public inputs which will be submitted in the summer of 2024 for the 2027 revision. These changes will attempt to provide updated guidance in both article 130 and Annex D.5, which will improve overall worker safety and provide more accurate guidance. Multipliers for events in panels and cabinets will also be considered.
Test Data:
22 dc arc flash tests were conducted at 192, 240, and 480 V with 5 kA and 20 kA available current. Closed parallel electrodes in both open air and enclosed configurations, with calorimeter set at 18″ distance, and an additional calorimeter at 6″ distance for certain tests. Reported data include arc current, arc voltage, arc duration, arc energy, incident energy, and electrode gap, with high-speed video observations for relevant tests. Voltage and current waveforms were digitized to create time series data.
Publication | DOI: 10.1109/ESW42757.2020.9188336 | Test Data
Recommended Citation:
K. Gray, S. Robert and T. L. Gauthier, “Low Voltage 100–500 Vdc Arc Flash Testing,” 2020 IEEE IAS Electrical Safety Workshop (ESW), Reno, NV, USA, 2020, pp. 1-7, doi: 10.1109/ESW42757.2020.9188336.
Abstract:
Does an arc exist, and can it be maintained below 100 Vdc, and is there a danger for your workers at your facilities? To answer these questions, we developed a test plan and requested testing at high voltage test laboratories. The arc flash tests were performed to measure the range of incident energy that may be present during an arc flash incident while live maintenance is performed on low voltage dc. The laboratory carried out the tests in a controlled environment to replicate systems voltage and fault current on equipment found in our facilities. The results should give us better understanding of arc flash risks at low voltages, and help us make appropriate decisions regarding the personal protective equipment required.
Test Data:
23 dc arc flash tests were conducted ranging from 105 V to 500 V with 7 kA to 20 kA available current. Testing was done in inline configuration in both enclosed ceramic box and open air, with calorimeters at 450mm (18″) from electrodes with initial gaps of 3mm, 6mm or 25mm. Electrode erosion increased substantially with arc duration and voltage: the reported max/average gaps were 6/6 mm at 105 V (6mm), 5/4 mm at 105 V (3mm), 25/16 mm at 144 V (6mm), 69/38 at 260 V (6mm), and 130/68 mm at 520 V (6mm). Voltage and current waveforms were digitized to create time series data.
Publication | DOI: 10.1109/PESGM.2018.8586181 | Test Data
Recommended Citation:
J. G. Hildreth and K. Feeney, “Arc Flash Hazards of 125 Vdc Station Battery Systems,” 2018 IEEE Power & Energy Society General Meeting (PESGM), Portland, OR, USA, 2018, pp. 1-5, doi: 10.1109/PESGM.2018.8586181.
Abstract:
Arc flash incident energy studies are critical in determining appropriate personal protective equipment for electrical workers. While ac incident energy calculation methods have been refined based on extensive testing, available methodologies for calculating dc incident energy rely on conservative assumptions due to lack of experimental results. Consequently, workers may be unnecessarily encumbered with excessive PPE. To better quantify the dc arc flash hazard that Bonneville Power Administration employees are exposed to, laboratory testing was performed to replicate the most severe conditions electrical workers were likely to encounter. Using a flooded lead-acid station battery, faults were initiated, such that fault current and incident energy could be measured. Results showed that industry-standard arc models overestimate the incident energy by more than a factor of ten. It was concluded that BPA electrical workers were not reasonably exposed to more than 4 Cal/cm2, and required PPE was reduced to Level 1 for all 125 VDC station battery circuits.
Test Data:
Original experimental measurements from 58 dc arc flash tests conducted on a 125 V 1300 Ah station battery system with available currents of roughly 3.9 kA and 7.85 kA in closed parallel, open parallel, and inline configurations using 6.35mm and 12.7mm gaps. Variations included charger contribution, added inductance, loose/fixed tools, and using a panel board.