What is the semantic purpose of down conductors in a lightning protection system?

The semantic purpose of down conductors in a lightning protection system is to connect air terminals to the ground. Down conductors are critical components of the system that safely channel the electrical energy from a lightning strike down from the air terminals, which capture the strike, directly to a grounding system. This establishes a low-resistance path for the lightning current to travel safely into the earth, minimizing the risk of damage to the structure and its occupants.

Without down conductors, the captured lightning would have no safe way to dissipate into the ground, increasing the potential for damaging surges of electricity that could impact the building and its electrical systems. This connection is essential for ensuring that the lightning protection system operates effectively and provides the necessary protection against lightning strikes.

The other options do not encompass the primary function of down conductors. Redirecting lightning strikes to higher structures is not the purpose of down conductors, as their role is to manage and direct energy rather than modify the strike's point of incidence. Acting as weather indicators is unrelated to their function in a lightning protection system. Finally, while down conductors may provide some support to other components, their primary role is focused on ensuring a safe conduit for lightning energy to the ground.