2014 Version of NFPA-780:
A Summary of Changes from the 2011 Version
The newest edition of 780 is available ($44.50) from NFPA at www.nfpa.org
SThe 2014 version is the 33rd edition of the document first published in 1904. It rules over all previous editions. Major changes include:
- Re-organization of Sections 4.7 and 4.8, Strike Termination Devices.
- Section 4.8 clarifies small objects on roofs.
- Sections 4.15 through 4.21 are improved with major changes about bonding.
- There is a new Chapter 11 covering airfield lighting (not lightning !) circuits.
- There is a new Chapter 12 covering solar arrays and their circuits.
- The Annexes provide very useful information which should not be overlooked. By example, details on catenary AT designs are very well presented. We suggest that all the Annexes be read first, before marching into the main body of the 780 Chapters.
Some Caveats in the Annexes provide good guidance. Example: A.18.104.22.168 about ratings of
SPDs. The Annex says: …larger ratings that protect against less probable but more powerful lightning events will usually provide a better capability to handle multiple strikes and will usually provide a longer service life. We agree and suggest SPD Mains at min. 250kA and Branch SPD at min. 125kA. Don’t ignore SPDs at all comms/data/signal circuits !
Remember: ATs do not provide any defenses for electrical/electronic operations. Only the judicious application of SPDs, in a layered methodology, will provide LP here.
We recommend the 2014 version of NFPA-780 as essential for the LP engineer and all other persons interested in fulguration mitigation, or LP. NLSI teaches the 2014 version of NFPA-780 as an integral part of all classes.