Radius of Protection

The radius of protection of Forend Early Streamer Emission(E.S.E) lightning conductor is related to its height (h) relative to the area to be protected, to its; triggering advance and to the selected protection level.

Rp = √ h(2D – h) + ∆L (2D + ∆L) with h ≥ 5m.

Rp = radius of protection

h = tip of Forend ESE

D = triggering distance
      20m for protection level I,
      30m for protection level II,
      45m for protection level III,
      60m for protection level IV.

∆L = upward leader length gain

∆L₍m₎ = V₍m/µs₎ • ∆T₍µs₎ (V = 1m/µs)

∆T = triggering advance

Reference: French Standard NFC 17 -102