Protection Calculation | Lightning

Lightning protection isn’t just about installing a rod on a rooftop—it requires careful calculation to ensure safety and compliance with international standards like or NFPA 780 . Below is a clear breakdown of the key calculations involved.

Where:

Nd=Ng×Ae×C1×10-6cap N sub d equals cap N sub g cross cap A sub e cross cap C sub 1 cross 10 to the negative 6 power Ngcap N sub g (Flash Density): Average annual ground flashes per km2k m squared in the area. Aecap A sub e

Note: A minimum of two down-conductors is always required for a structure.

), which is the effective ground area a structure "covers" for lightning strikes.