What is a lightning rod?
It is an interception system that has the aim of intercepting atmospheric electric discharges and conducting them safely to earth. Any interception system (lightning rod) should meet the national and international standards or laws that are applied to it (mainly standards UNE 21.186, NFC 17.102, Technical Building Code SU8, Series IEC/EN 62.305 and IEC/EN 62.561).
How is a lightning rod installed?
The lightning rod, in order to fulfill its function, must always be installed above the highest part of the building or structure to be protected so that it captures the electrical discharge from lightning and allows a safe path to earth.
What elements make up a lightning protection system?
The components of a lightning protection system are:
- Interception system (ESE air terminals or Franklin rods and meshes).
- Two or more down-conductors
- An earth termination system
- A suitable surge protection installation
- Other measures minimizing the destructive effects of lightning (equipotential bonding, screening etc.)
Why should I install a lightning rod?
The aim of a lightning protection system is:
1) To capture lightning
2) To conduct lightning current safely to earth
3) To dissipate the lightning current to the ground
4) To provide protection against the secondary effects of lightning
In a world where buildings and equipment are becoming more complex, lightning represents a hazard. One discharge can damage buildings and cause failures in electronic equipment. It can even provoke a fire and lead to serious economic losses.
Which are the effects of lightning and why do we use a lightning rod?
- Electrical effects: equipment destruction. Increase in ground voltage and surges can damage the equipment connected to the electrical network.
- Electrodynamic effects: damage to buildings. Deformations and breakages in the structure due to the force generated by the high magnetic field produced.
- Thermal effects: fires. Sparks and heat dissipation by the Joule effect can cause fires.
- Effects on people and animals: electrocutions and burns. Current of a certain intensity passing through the body for a short period of time is enough to cause the risk of electrocution due to cardiac or respiratory arrest. Besides, there is risk of burns.
- Inductive effects: Within a variable electromagnetic field, induced currents appear in every conductor. If these conductors reach computers or other electronic equipment, irreversible damage may be produced.
What types of lightning exist?
Aplicaciones Tecnologicas, manufacturer specialised in protection systems against atmospheric electric discharges, puts at your disposal both passive systems and early streamer emission (ESE) air terminals. Here, we explain how each one works:
Early streamer emission air terminals base their operation on the electric characteristics of lightning formation. Lightning initiates with a downward leader spreading in any direction. Once it approaches the objects placed on the ground any of them can be struck. ESE Lightning air terminals are characterized by emitting the continuous upward leader before any other object within their radius of protection. The lightning rod must be the controlled point of impact of the discharge so that it provides the lightning current with a path to ground without damaging the structure. The main standards governing this type of lightning protection systems are: NFC 17-102, UNE 21186, NP 4426.
- Franklin rods and meshed conductors (Passive systems)
Lightning protection using Franklin rods and meshed conductors is used to share and dissipate the lightning current through a network of down-conductors and earth terminations. Sections and materials must meet the requirements of the standards that define this type of system (IEC/EN 62305 series, IEC/EN 62561 series).
How to know if I should install a lightning rod
If you have any doubts about whether or not you should install a lightning rod, in Aplicaciones Tecnológicas we can prepare a customized study based on the standards and your specific needs. You can contact our technicians by clicking here.