Lightning rods, flagpoles
Lightning protection is an important safety feature of every building. A high mast provides the atmospheric spark charge (or lightning) offset arising from the potential difference between the atmosphere and the earth. Lightning rods can counteract the sparking, protect internal wiring and devices that exclude the formation of dangerous induced currents.
Lightning rods consist of 4 main elements:
Lightning receiver located at the uppermost point and being a metal pin that mounts on top of the mast:
- Mast as drainage current for the connection with grounding streak.
- Grounding streak provides charge drainage to ground.
- Ground circuit – steel rods, clogged into the ground.
Standard lightning protection area is calculated in a circular cone with the top at the extreme point of the lightning rod and the ground level. The radius of the protection area is equal to the height difference between highest points of the building and the lightning rod multiplied by 1,732.
It’s always important to understand that a single lightning rod is less preferred option because it operates unilaterally. Therefore, for reliable lightning protection the mast must be made very high.