[TowerTalk] More lightning stuff
jimlux at earthlink.net
Mon Sep 15 20:01:24 EDT 2008
Ran across another interesting paper:
http://www.lightningsafety.com/nlsi_lhm/Radials.pdf, a paper by Moore, et al, from the Langmuir Lab.
Their recommendation is that radials for lightning dissipation should extend 8-10 meters from the down conductor. (based on height of stepped leader and the surface charge distribution)
They also point out that a standard rod has sufficient inductance (2.4 uH, est) that it's not a particularly good lightning current sink, because it would still result in a radial electric field of several hundred kV/m. That field would result in radial streamers forming and propagating outward.
The concern overall is that of "surface arcing"
More information about the TowerTalk