The External Lightning Protection System is required to intercept the direct lightning flashes to the structure, including flashes to the side of structure, and conduct the lightning current from point of strike to Earth.

The ideal lightning protection for a structure and its connected services would be to enclose the structure within an earthed and perfectly conducting metallic shield.

This in essence would prevent the penetration of the lightning current and induced electromagnetic field into the structure.





IS / IEC 62305-3 advocates the following, in any combination, for the design of air termination system:

• Air rods whether they are free standing mast or linked with conductors to form a mesh on the roof.
• Catenary conductors, whether they are supported by free standing mast or linked with conductors to form a mesh on the roof.
• Meshed conductor network that may lie in direct contact with the roof or be suspended above it.