Incident energy
Updated 2026-10-27
Data records
- Incident energy is the thermal energy per unit area that an arc flash delivers to a surface at a stated distance from the arc source; arc flash hazard analysis estimates it at the working distance to set the arc flash boundary and choose the protective clothing, and it is usually expressed in calories per square centimeter or joules per square centimeter.
- Clause 130.5(G) of NFPA 70E-2027 bases the incident energy analysis on the working distance for the task and on the clearing time of the overcurrent protective device including its condition of maintenance; the analysis is updated when the system changes and reviewed at a maximum interval, and its result, the available incident energy with its working distance, is one of the items an equipment label may carry under clause 130.5(H).
Sources
- Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
- NFPA 70E-2027, Standard for Electrical Safety in the Workplace, 2027 edition, NFPA. Cited: clause 130.5(G). Held as: Purchased single-user copy. Publisher page for NFPA 70E-2027
Obtaining the documents
- NFPA 70E-2027: available from the publisher
Changelog (2 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.incident-energy.definition) | |
| 2026-10-27 | created (gloss.incident-energy.nfpa70e.analysis) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Incident energy." Arc Flash Reference. 2026-10-27. https://www.arcflashreference.com/glossary/incident-energy/.
Arc Flash Reference, Incident energy (Oct. 27, 2026), https://www.arcflashreference.com/glossary/incident-energy/.
@misc{etr-glossary-incident-energy,
title = {Incident energy},
howpublished = {\url{https://www.arcflashreference.com/glossary/incident-energy/}},
organization = {Arc Flash Reference},
publisher = {Arc Flash Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Incident energy |website=Arc Flash Reference |publisher=Arc Flash Reference |url=https://www.arcflashreference.com/glossary/incident-energy/ |date=2026-10-27 |access-date=}}