Lightning Current Propagation in Electrical Conduit

Journal Article · 29 December 2021 · IEEE Transactions on Plasma Science

DOI: https://doi.org/10.1109/tps.2021.3136447 · OSTI ID:1875497

Brooks, William  ^[1]; Lapointe, Micah ^[1]; Collier, Landon ^[1]; Mankowski, John  ^[1]; Dickens, James  ^[1]; Hattz, David  ^[2]; Koone, Neil ^[2]; Neuber, Andreas  ^[1]

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1. Center for Pulsed Power and Power Electronics, Lubbock, TX (United States)
2. Pantex Plant (PTX), Amarillo, TX (United States)

Investigation of lightning strikes to conductors ran through long spans of rigid steel conduit was performed. An overdamped-exponential current waveform with controlled peaks and rise rates was used to inject simulated lightning strikes. The impact of the length of wire, length of conduit, grounding location/s, and load type was investigated. Breakdown of 600 V, 12 AWG, THHN insulated wire (3.23 mm OD, 2 mm conductor diameter) was observed for voltages above 45 kV. The presence of resistive loads (between wire and ground) in excess of 20 ohms, or current rise times in excess of 5 kA/μs were found to consistently produce breakdown between wire and conduit. Practical power circuit elements such as outlets and splices were found to breakdown at voltage levels much below the wire insulation failure threshold.

• Research Organization: Pantex Plant (PTX), Amarillo, TX (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: NA0001942
• OSTI ID: 1875497
• Report Number(s): IROS22597
• Journal Information: IEEE Transactions on Plasma Science, Journal Name: IEEE Transactions on Plasma Science Journal Issue: 1 Vol. 50; ISSN 0093-3813
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English