Installed at high points, air terminals are pointed metal rods or tubes. Proper height and spacing of the terminals depends on the building configuration. Terminals are installed along roofs and on all projections such as chimneys, flagpoles, towers, dormers, ventilators and water tanks. They connect air terminals with each other and with grounds. Each down conductor should have a separate ground.
Secondary conductors connect metal parts of a building together.
The electrical bond this creates keeps lightning from flashing across the gap between the metal parts. All secondary conductors are connected to the main conductors. Numerous metal parts that are part of or attached to a building may need this protection. Metal roofing is a common trouble spot if not properly grounded. Other examples include metal hay tracks, door tracks, troughs, storage tanks, stalls, stanchions, milking lines, water lines, pipes, conveyors, long metal ducts, concrete reinforcement and more.