When using structural steel as a down conductor, what is the minimum area for the bonding plate?

When using structural steel as a down conductor in lightning protection systems, the minimum area for the bonding plate is indeed set at 8 square inches. This requirement is based on ensuring that the bonding connections provide adequate surface area to ensure effective electrical conductivity and that they minimize resistance between the bonding plate and the structural steel.

A larger bonding area allows for better contact and connection, which is essential for the safe dissipation of lightning energy. The specified area helps to accommodate variations in surface conditions and guarantees that the bond is reliable and durable over time. Therefore, having a bonding plate of this size is critical for maintaining the integrity and performance of the lightning protection system.