Arc-Flash Hazard Calculations in LV and MV DC Systems-Part I: Short-Circuit Calculations

• Published in: IEEE transactions on industry applications Vol. 50; no. 3; pp. 1687 - 1697
• Main Author: Das, J. C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Arc flash hazard in DC systems; Batteries; calculation of short-circuit currents in DC systems; converters; DC motors and generators and capacitors; Devices; Direct current; Documents; Fire protection; Hazards; IEC; Inductance; Mathematical analysis; Methodology; Protective; Resistance; Short-circuit currents; calculation of short-circuit currents in dc systems; and capacitors; converters; batteries; Arc-flash hazard in dc systems; dc motors and generators
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/TIA.2013.2288416

The IEEE 1584 Guide does not address arc-flash hazard in dc systems. The interest in this subject is evidenced by current publications. The National Fire Protection Association (NFPA) 2012 methodology has added a small description of the calculations of arc-flash hazard in dc systems. However, there are serious inaccuracies in the application of the methodology that is advocated in the NFPA. A review of the current literature indicates that there is no comprehensive document on the subject and that some of the assumptions made in the current literature are not accurate, e.g., with respect to the short-circuit current profiles and protective devices in dc systems, which are very fundamental to the accurate calculations of arc-flash hazard in dc systems. This paper is presented in two parts. This part provides equations with practical examples of short-circuit calculations in dc systems. The second part provides the analysis of arc-flash hazard. Accurate calculations of the short-circuit currents and ascertaining their profiles is the first step in the arc-flash hazard analysis.