What is the minimum stranded size for a Class II aluminum main lightning conductor?

In the context of lightning protection systems, the size of the main lightning conductor is critical for ensuring adequate conductivity and safety. For Class II aluminum conductors, the minimum stranded size specified is essential to accommodate the electrical requirements and mechanical strength needed for effective lightning interception and grounding.

The standard gauge for a Class II aluminum main lightning conductor is 13 AWG. This gauge strikes a balance betweeen conductivity and flexibility, allowing for effective performance during a lightning event while still being manageable in terms of installation. Using a conductor below this size might lead to increased resistance, which could affect the system's ability to safely carry the electrical charge generated by a lightning strike, thus compromising the protection offered to the structure.

In contrast, alternative sizes like 14 AWG, 16 AWG, and 12 AWG do not fulfill the minimum requirement established for Class II aluminum conductors in lightning protection systems, leading to insufficient protection. A size of 12 AWG may exceed the minimum needed, while the smaller sizes could fall short of ensuring reliable conductivity. Thus, 13 AWG is identified as the minimum necessary size for effective lightning protection.