Lightning Protection Calculator
Calculate protection requirements per NFPA 780 and IEC 62305.
Protection Levels (IEC 62305)
| Level | Sphere (m) | Mesh (m) | Efficiency |
|---|---|---|---|
| I | 20 | 5 x 5 | 98% |
| II | 30 | 10 x 10 | 95% |
| III | 45 | 15 x 15 | 90% |
| IV | 60 | 20 x 20 | 80% |
Lightning Protection System Components
Strike Termination
- Air terminals (lightning rods)
- Catenary wire systems
- Mesh conductors on roof
- Min 10" above protected equipment
Grounding System
- Ground rods (min 2 per down conductor)
- Ground ring around structure
- Bonding to building steel
- Target resistance: <10 ohms