Lightning Protection (IS/IEC 62305-3)
The main and most effective measure for protection of structures against physical damage is the lightning protection system (LPS). It usually consists of both external and internal lightning protection systems.
An external LPS is intended to.
- Intercept a lightning flash to the structure (with an air-termination systemm)
- Conduct the lightning current safely towards earth (using a down-conductor system)
- Disperse the lightning current into the earth (using an earth-termination system)
An internal LPS prevents dangerous sparking within the structure using either equipotential bonding or a separation distance (and hence electrical insulation) between the external LPS components and other electrically conducting elements internal to the structure.
The probability of structure penetration by a lightning current is considerably decreased by the presence of a properly designed air-termination system. Air-termination systems can be composed of any combination of the following elements:
Rods (including free-standing masts)
Acceptable methods to be used in determining the position of the air-termination system include
- The protection angle method
- The rolling sphere method
- The mesh method