Lightning Protection Calculation ((link)) May 2026

For an isolated rectangular building:

| LPL | Peak current (kA) | Rolling sphere radius (m) | Mesh size (m) | |------|------------------|---------------------------|---------------| | I | 200 (minimum 3) | 20 | 5 × 5 | | II | 150 (min 5) | 30 | 10 × 10 | | III | 100 (min 10) | 45 | 15 × 15 | | IV | 100 (min 16) | 60 | 20 × 20 |

(approx.):

[ A_d = L \times W + 2 \times (L + W) \times H + \pi \times H^2 ]

The calculates zones protected by air terminals: A sphere of radius ( r ) (from table above) is rolled over the structure. Any surface touched by the sphere needs direct protection. 5. Down Conductor Spacing Number of down conductors required: lightning protection calculation

:

[ n = \fracPd ]

[ R = N \times P \times L ]