What is the minimum diameter of a Class II aluminum air terminal?

The minimum diameter of a Class II aluminum air terminal is indeed 5/8 inch. This specification is vital as air terminals, also known as lightning rods, play a crucial role in a lightning protection system by intercepting lightning strikes and directing the electrical energy safely into the ground.

In lightning protection systems, different classes of air terminals have different requirements based on their intended use and the level of protection needed. A Class II air terminal, which is intended for use in the standard lightning protection configurations, needs to have a minimum diameter that ensures adequate strength and effectiveness in protecting a structure.

The specified diameter of 5/8 inch ensures that the terminal has sufficient surface area to withstand the forces of a lightning strike and to effectively redirect the energy. Having a diameter smaller than this could compromise the terminal's ability to function properly, potentially resulting in inadequate lightning protection.

Thus, understanding these specifications helps ensure that the installed lightning protection systems are capable of performing their protective functions effectively, contributing to the safety and longevity of the structures they are designed to protect.