There are various types of external lightning protection technology, and questions commonly arise about the differences between them. To understand them properly, it is not enough simply to compare the equipment; it is also necessary to analyse how a lightning strike is intercepted and what design criteria each installation requires.
Different external lightning protection technologies for a single objective
Lightning protection is an essential element in the design of many infrastructures, particularly those where the safety of people and operational continuity are priorities. There are several external lightning protection technologies. Among the most widely used are conventional systems, based on air terminals or meshed cages (Faraday cages), as well as ESE systems (Early Streamer Emission lightning rods).
These two systems pursue a common objective: to intercept the atmospheric discharge and safely conduct the lightning current to earth. The choice between these two solutions must be made on the basis of technical criteria and the real needs of the installation. Depending on the characteristics of the infrastructure and its environment, it is possible to opt for a conventional system, an ESE system, or even a combination of the two in order to ensure effective lightning protection.
How is an atmospheric discharge formed?
Before analysing each lightning protection system in detail, it is important to understand how an atmospheric discharge is formed.
During a storm, accumulations of electric charge occur inside the clouds. In general, the upper part of the cloud accumulates positive charges, while the lower part accumulates negative charges. When this difference in potential becomes large enough, the electric field between the cloud and the ground, or between two clouds, becomes unstable. This imbalance generates an intense electric field between the cloud and the earth’s surface.
When the electric field reaches values high enough to overcome the insulating capacity of the air, the atmospheric discharge process begins. At that moment, downward leaders develop from the cloud, while upward leaders form from the ground or from elevated structures.
When these two leaders meet, the phenomenon we call lightning occurs. The function of an external lightning protection system is to encourage the discharge to strike within a controlled area and to conduct the lightning current to earth along a safe path.
What is a conventional protection system?
The conventional systems use air terminals and/or meshed capture networks distributed over the structure. Their operation relies on the correct positioning of the capture elements and on the geometric design of the volume to be protected. To this end, recognised methods are applied, such as the rolling sphere method, the protection angle method or the mesh method.
This type of system can be particularly suited to structures where the distribution of several capture points makes it possible to effectively cover the area to be protected while complying with regulatory requirements. In all cases, the design must be completed with down conductors, an appropriate grounding system, as well as the necessary equipotential bonding and internal protection measures.
What is an early streamer emission (ESE) lightning rod system?
ESE systems incorporate a device designed to encourage the formation of the upward leader under storm conditions. This technology makes it possible to extend the protection area compared with a single conventional air terminal, while complying with the criteria set out in the applicable regulations.
The ESE lightning rods are commonly used in installations where it is necessary to protect large surfaces, isolated structures, open spaces or buildings where the aim is to reduce the number of elements visible on the roof. They can also be a suitable solution in projects where optimising the design, reducing the materials used and limiting the visual impact are important factors.
Main differences between conventional systems and ESE systems
The main difference between these two systems lies in the way the protection area is designed and in the distribution of the capture elements. In conventional systems, protection generally requires a greater distribution of air terminals, conductors or meshed networks across the structure. In ESE systems, the triggering device makes it possible to protect more extensive areas with a reduced number of air terminals, depending on the model used, the installation height and the applicable regulations.
This does not mean that one system replaces the other. In many cases, the two solutions meet different needs and may even form part of complementary strategies within a broader lightning protection project. The choice must be based on a technical study taking into account, among other things, the type of structure, the level of risk, the use of the installation, the environmental conditions, as well as the regulatory requirements of the country where the project is carried out.
INGESCO, solutions adapted to each project
Whatever technology is chosen, the effectiveness of lightning protection does not depend solely on the capture device.
A correctly designed system must take into account the entire path of the current, from the point of impact through to its dissipation into the ground. This includes the down conductors, the grounding system, the equipotential bonding, the surge protection as well as the appropriate selection of materials. Even a perfectly suited air terminal loses its effectiveness if the rest of the system is not correctly sized or installed. That is why talking about lightning protection does not come down solely to talking about lightning rods. It is a comprehensive system that must operate in a coordinated way at the moment of the discharge.
At INGESCO, we design lightning protection solutions taking into account the reality of each project. Our technical team analyses each case in order to define the system best suited to each situation. This approach allows us to tailor the solution to the real needs of the infrastructure, avoiding generic approaches and guaranteeing effective protection.
With more than 50 years of experience in the sector, we work to offer reliable, durable and technically proven systems, both in external protection and in internal protection and grounding.
If you would like to determine which lightning protection system is best suited to your project, our team is at your disposal to support you.
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