Aluminum Building Wire (AA-8000 Series)

What it is

AA-8000 series aluminum is an electrical-grade alloy with small additions, mainly iron, that improve creep resistance and make the conductor behave better under terminal pressure. ASTM B800 covers the 8000 series wire itself. ASTM B801 covers concentric-lay stranded 8000 series conductors made for insulation. Most aluminum feeders, service conductors, SER and SEU cable and large building wire sold today use this alloy. Many products also use compact stranding, which squeezes the strands to reduce the overall diameter.

The NEC (310.14 in recent editions) requires solid aluminum conductors in 8, 10 and 12 AWG, and stranded aluminum 8 AWG through 1000 kcmil in common building wire and service-entrance types, to be AA-8000 series alloy.

How to identify

Read the print on the jacket. It shows the type letters (XHHW-2, THHN, USE-2 and others), size, "AL" and often "AA-8000" or the alloy name. Compact conductors are marked "compact." The cut end shows bright aluminum strands. See the building wire letter code decoder.

Termination markings

Key points

• Aluminum needs a larger conductor than copper for the same load. Size from the NEC ampacity tables, not by trading sizes by rule of thumb.
• Use lugs and connectors marked for aluminum. Compact conductors need connectors listed for compact stranding.
• Tighten to the value on the lug or device label with a calibrated tool. Loose aluminum terminations heat up and fail.
• Use oxide-inhibiting compound when the connector maker calls for it. Some connectors come pre-filled.
• Wire-brush or abrade the strands per the connector instructions to break the oxide film.
• Twist-on connectors for aluminum-to-copper must be specifically listed for that use.

Common mistakes

• Landing aluminum on a CU-only terminal.
• Skipping the torque value on the label.
• Using a standard compression connector on compact conductor.
• Treating old 1350 alloy branch-circuit wire as if it were AA-8000.

Governing standards: NEC Article 310 (310.14 conductor material); NEC 110.14 (terminations); ASTM B800; ASTM B801; UL 486A-486B (wire connectors).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.