What is the minimum contact area required for connectors of cable conductor to structural steel?

The minimum contact area required for connectors of cable conductor to structural steel is specified to ensure effective electrical conductivity and proper grounding in lightning protection systems. Having a sufficient contact area is critical for minimizing resistance at the connection point, which can cause overheating or failure during a lightning strike event.

In this context, three square inches is the correct specification because it provides an adequate surface area to establish a reliable electrical connection between the cable conductor and the structural steel. This minimizes the chances of contact resistance that could diminish the system's overall effectiveness during a lightning event.

A larger contact area, such as four or five square inches, may offer even better conductivity but exceeds the minimum requirement. On the other hand, two square inches would not be sufficient to ensure the necessary conductivity and safety, highlighting the importance of adhering to established standards for lightning protection installations.