NEC 310.3 Changes to Conductor Types in the 2023 NFPA 70

[jar546]

This section correlates with the UL listing requirements for testing terminations — such as copper-aluminum, revised (CO/ALR) devices, and other connectors — suitable for use with aluminum conductors. The electrical industry has developed AA-8000 series aluminum alloy materials and connectors suitable for use with aluminum conductors to provide safe and stable connections. Connections suitable for use with aluminum conductors are also generally listed as suitable for use with copper conductors and are marked accordingly, such as AL7CU or AL9CU. Numbers 7 and 9 identify the temperature ratings of 75°C and 90°C, respectively, for these terminations.

Copper-clad aluminum conductors are manufactured so that copper forms a minimum of 10 percent of the cross-sectional area of a solid conductor or of each strand of a stranded conductor.

 

[Paul Sweet]

I still don't think I'll specify it or recommend approval as a substitute until it has demonstrated several years of satisfactory performance under field (not laboratory) conditions.