Taller buildings in general attract lightning strikes, hence an efficiently designed LPS is highly critical to safeguarding these structures from the destruction caused due to lightning. Also, such structures should make sure quality earthing systems and surge protection devices are installed to protect the lives and expensive electronic equipment housed in these structures. National Building Code guidelines to be followed while designing LPS for such tall buildings.
Design of Lightning Protection System for high rise building:
1. A lightning protection system for structures could be done by any of the following methods.
- Protection angle method
- Mesh method
- Rolling sphere method
2. The protection angle method is suitable for simple-shaped buildings. It also has limitations on the height of the air terminal.
3. When a building height is more than 60m at level 4, Then the protection angle method is not applicable.
4. The rolling sphere method can be used in all types of buildings but by using this method we can place air terminals on the upper part of the structure. If the height of the building is greater than the radius of a sphere the possibility of a side flash may hit the structure.
5. Since it is a taller structure, major lightning flashes will hit on the top, horizontal leading edges, and corners but IEC 62305 -3 suggests providing lateral protection, reduces side flashes (i.e) if the building height exceeds 60m the 20% of the top should be protected by the lateral protection system.
6. The mesh method is suitable for the protection of plane surfaces and the lateral surfaces to protect against side flashes