Brazil is among the countries with the most lightning strikes in the world. According to research, approximately 70 million lightning strikes occur annually, affecting about 300 Brazilians. Therefore, there is a need for the implementation of... SPDA projects.
Also known by the popular name of lightning rods, Lightning Protection Systems are primarily responsible for preventing accidents and controlling the electrical charge produced by these natural elements. Learn about some types of this system and how it works in this article.
So, what exactly is a lightning protection system (LPS) project?
SPDA means Lightning Protection System, This design showcases a set of structures and solutions whose main function is to protect people and buildings of various types. Through the project, lightning strikes are captured and dissipated, directing them to the ground.
The project, as a whole, consists of a series of CAD drawings, as well as stamps, technical notes, “Technical Responsibility Annotation”, Additional data and details. Lightning rods, in particular, are part of the system and consist of structures of conductive cables, rods, and the grounding process.
Project relevance
Without a doubt, a lightning protection system (LPS) project is extremely important for everyone's safety. However, even if they are somewhat effective, it's worth noting that lightning cannot be entirely controlled, given that it is a well-known natural phenomenon.
This type of project aims to prevent greater damage to structures or human beings by creating containment areas. To carry it out, measures such as isolating exposed conductive parts and using physical formulas are implemented.
Even with numerous attempts and the utmost professional experience, accidents cannot be completely avoided. However, by using a lightning protection system (LPS) to protect the site, the chances of lightning strikes are reduced, as are the traces they leave behind.
What are the models for this type of project?
Given that research focused on safety has grown over time, various methods have been developed to mitigate the damage caused by lightning. Learn about them below.
1. Franklin Method
The Franklin Method consists of implementing a metal rod with lightning rods, connected to two additional conductors grounded together in a down conductor system. This system was created around 1753 by Benjamin Franklin, a well-known scholar who named the method the "lightning rod system".
This carefully designed structure is placed on top of a building, where the protective volume will consist of a cone-shaped area extending from the top to the base of the building. Ideally, this method should be used in buildings with little horizontal area, with a maximum height of 45 meters or 15 stories.
2. Faraday Cage Method
The Faraday cage method, in turn, uses the internal electric field of a cage, which is zero, to generate greater protection for the building and, consequently, for the people. Thus, the interior of the structure remains protected while there is an electrified field on its surface.
In general terms, the structure is organized using collectors that form horizontal conductors, gathered in a metal mesh. This same mesh is connected to the ground at a convenient distance, and shortly afterwards installed on top of the building, in a shape similar to a cage.
This method is best suited for low-rise buildings, such as those owned by companies with warehouses.
3. Electrogeometric or rolling sphere method
The electrogeometric method, also known as the rolling sphere method, can also be called the "dummy sphere" method. This model allows for the creation of a dummy sphere that rolls through the structure, preventing lightning strikes and the resulting damage.
In areas where the wheel can touch the building, there is a greater chance of an electrical discharge. This makes it necessary to protect it with lightning rods, which generally follow the Franklin model. The larger the sphere, the greater the amount of protection afforded to the location.
This method is recommended for extremely tall buildings with high architectural complexity.
How is a lightning protection system (LPS) project developed?
A lightning protection system (LPS) project goes through a whole process to be developed. First of all, professionals need to thoroughly analyze the location that will require protection. They will also need to take into account the conditions surrounding the structure, such as its height.
From this point on, the entire project and its management must take into account NBR 5419, which addresses the following points:
- risk management;
- choice of method;
- delimitation of protective resources;
- choice of grounding conductor;
- Defining the need for descents;
- Surge protection measures design;
- indication of potential equalizations;
- Calculation of appropriate safety distances.
In addition to implementing all these specifications, it is important to have an inspection and maintenance of the entire lightning protection system, as well as to ensure the safety of the professionals involved in its execution.
Specialization is the solution.
Although there is no way to completely eliminate lightning strikes, those involved in a lightning protection system (LPS) need to know how to handle the complexity of each project. This will facilitate daily work and generate better results at the end of all projects.
When a project is being developed, it's important to keep in mind that all decisions will be extremely important for the durability of the installation's lifecycle. Through proper analysis, the project will not only be efficient but will also have its costs reduced.
Investing in lightning protection systems is the necessary solution to reduce accident rates and losses caused by lightning strikes, which constantly occur in Brazil.
