Where:
| Parameter | Typical Equation / Method | |----------------------|------------------------------------------| | Risk assessment | ( R = N \times P \times L ) | | Collection area | ( A_d = L\times W + 2(L+W)H + \pi H^2 ) | | Annual strike number | ( N_d = N_g \times A_d \times C_d \times 10^-6 ) | | Protection zone | Rolling sphere radius (20–60 m) | | Down conductor count | Perimeter / spacing (10–20 m) | | Step voltage safety | ( V_step = \fracI \rho2\pi r ) | lightning protection calculation