Which statement correctly identifies the minimum size for aluminum or copper-clad aluminum conductors?

• A. 6 AWG
• B. 4 AWG
• C. 8 AWG
• D. 10 AWG

Answer: (A)

When sizing conductors that are aluminum or copper‑clad aluminum, the smallest acceptable size is driven by two factors: how much current the conductor must safely carry (ampacity) and how it will be terminated in equipment. Aluminum and copper-clad aluminum have higher resistance and heat rise than copper, and many lugs, terminals, and devices are rated to accept a minimum conductor size. For typical installations, 6 AWG is the smallest size that can be safely terminated and provide adequate ampacity under common protection settings. Sizes smaller than that—8 or 10 AWG—often don’t meet the required ampacity or termination requirements, and aren’t generally permitted as the minimum. A 4 AWG conductor would be larger than necessary for this rule, so the minimum is 6 AWG. Copper-clad aluminum is treated the same for these termination and ampacity considerations, so the minimum size remains 6 AWG.