Quick Answer
Air terminals play a crucial role in lightning safety by protecting structures from lightning strikes, reducing the risk of damage and electrical shock.
What are Air Terminals?
Air terminals, also known as lightning rods or air terminals, are metal structures designed to attract lightning and direct it harmlessly into the ground. They are typically installed on buildings, towers, and other structures to provide a safe path for lightning to follow. The most common shape for air terminals is a pointed spike or a rounded dome.
How do Air Terminals Work?
Air terminals work by creating a conductive path for lightning to follow. When a lightning strike approaches, the air terminal attracts the electrical charge and directs it into a grounding system, which safely dissipates the energy into the earth. The typical configuration for an air terminal includes a grounding system consisting of a copper rod or plate extending at least 20 feet (6 meters) into the earth to provide a secure path to ground. The size of the air terminal should be at least 3/8 inch (9.5 mm) in diameter, with a length of 1-2 feet (30-60 cm) above the roof or structure.
Installation and Maintenance Best Practices
Proper installation and maintenance of air terminals are critical to ensuring their effectiveness. Air terminals should be installed at least 10 feet (3 meters) above the highest point of the structure, and within 6-8 feet (1.8-2.4 meters) of the structure’s edge. They should also be spaced no more than 10 feet (3 meters) apart, with a maximum of 5 feet (1.5 meters) separation for structures with a height greater than 50 feet (15 meters). Regular inspections are necessary to ensure that the air terminal and grounding system remain secure and functional, including checking for signs of corrosion or damage.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.