What is the minimum diameter of a Class I solid copper air terminal?

The minimum diameter of a Class I solid copper air terminal is established to ensure adequate conductivity and durability for lightning protection systems. A diameter of 3/8 inch is specified to provide sufficient structural integrity and electrical conductivity when capturing and conducting lightning strikes. This size is designed to withstand the forces exerted during a lightning event and to minimize the risk of melting or damage to the air terminal itself.

Choosing a diameter less than 3/8 inch would not meet the requirements for effective lightning protection, as smaller diameters may not adequately handle the extreme currents and energies involved in a lightning strike. Therefore, the specification of 3/8 inch is critical for the effectiveness and reliability of the air terminal in providing safety and protection to structures.