Which material can be substituted for the main conductor?

The main conductor in a lightning protection system is critical for safely channeling lightning strikes to the ground. The primary function of this conductor is to provide a low-resistance path for the lightning current, which helps to prevent damage to structures and ensure safety.

A continuous rigid steel frame is an acceptable substitute for the main conductor because steel has excellent electrical conductivity and strength. It provides structural support as well as a conductive path, making it capable of handling large currents associated with lightning strikes. This dual functionality can enhance the overall effectiveness of the lightning protection system.

In contrast, other materials have limitations that prevent them from being suitable substitutes for the main conductor. Flexible aluminum cable, while conductive, may not provide the same level of durability and structural integrity as a rigid steel frame. Insulated copper wire, although an excellent conductor, lacks the necessary mechanical strength and may not be as effective in large-scale lightning protection applications. Non-metallic conduit cannot conduct electricity, making it completely unsuitable for this purpose.

By understanding these characteristics, it becomes clear why a continuous rigid steel frame is considered an appropriate alternative for the main conductor in lightning protection systems.