AAC vs. AAAC vs. ACSR: Comparing Overhead Aluminum Conductors

Three families of bare aluminum conductor carry nearly all of the overhead distribution and transmission load in North America: AAC, AAAC, and ACSR. They share the same 1350 aluminum in most of their strands and are sized in the same kcmil units, which is why a bid that says "795 kcmil bare aluminum conductor" can be answered three different ways, at three different prices, with three different sag-tension behaviors. This guide explains how each is built, where it earns its place on a line, and how to turn an engineering specification into the exact conductor to order.

The Three Constructions

AAC (All-Aluminum Conductor) is made entirely of hard-drawn 1350-H19 aluminum strands, manufactured to ASTM B231. It has the best conductivity of the three at 61.2% IACS and the lowest strength, so it is limited to the short spans typical of urban and suburban distribution, or to applications where the conductor is supported often. Because it is a single metal with no steel, it has no galvanic corrosion problem and is a good choice in coastal air. AAC codewords are flowers: Poppy, Tulip, Cosmos, Arbutus.

AAAC (All-Aluminum-Alloy Conductor) is made of 6201-T81 aluminum-magnesium-silicon alloy strands to ASTM B399. The alloy roughly doubles the tensile strength of 1350 aluminum at a cost of about 15% in conductivity (52.5% IACS). AAAC gives a strength-to-weight ratio comparable to ACSR without any steel, which makes it the standard answer for corrosive environments and for lines where a lighter conductor reduces structure loading. AAAC codewords are cities: Akron, Alliance, Butte, Greeley.

ACSR (Aluminum Conductor, Steel-Reinforced) wraps 1350-H19 aluminum strands around a core of galvanized steel wires, to ASTM B232. The steel core carries most of the mechanical load, allowing long spans and heavy ice and wind loads with very little sag, while the aluminum carries the current. ACSR is the default for transmission and for rural distribution with long spans. Its codewords are birds: Raven, Penguin, Linnet, Hawk, Drake, Falcon.

Side-by-Side Comparison

One Diameter, Three Conductors: The 1.108-Inch Example

The clearest way to see the trade-offs is to compare conductors that use the same hardware. Drake, the most common transmission ACSR in the country, has an overall diameter of 1.108 inches. Greeley AAAC was designed to match that diameter exactly, and Arbutus AAC matches Drake's 795 kcmil aluminum area. Approximate published values:

Greeley delivers roughly 90% of Drake's strength at 80% of its weight, in the same diameter, with no steel to corrode, and with about 17% more aluminum area to offset the alloy's lower conductivity. That is the AAAC proposition in one row. Arbutus is the lightest and most conductive of the three and costs the least, but with less than half the strength it needs shorter spans or lower tension. Values are rounded from manufacturer data; use the data sheet for the specific product you are bidding.

Reading an ACSR Stranding Ratio

ACSR is the only one of the three that comes in several constructions for the same aluminum area, and the stranding ratio is where bids go wrong. The notation is aluminum strands / steel strands.

Linnet, Merlin, and Oriole are all 336.4 kcmil ACSR. They have different diameters, different strengths, different weights, and different sag-tension charts. A bid that says "336.4 ACSR" without a codeword or stranding is incomplete, and a supplier who substitutes one for another has changed the line design. Always order by codeword.

Matching an Engineering Specification

An overhead conductor specification usually arrives as a codeword and a footage, sometimes with a paragraph of requirements attached. To turn it into a purchase order that matches, confirm each of the following.

Sample Lines That Price Correctly

• "12,000 ft Drake 795 kcmil 26/7 ACSR, ASTM B232, Class A galvanized core, non-specified (dry), on four reels, 3,000 ft minimum each. CTRs required."
• "6,500 ft Greeley 927.2 kcmil 37-strand AAAC, ASTM B399, single continuous length for river crossing, 96-inch max reel."
• "20,000 ft Poppy 1/0 AWG 7-strand AAC, ASTM B231, standard 5,000 ft reels."

What We Stock

Mid America Wire & Cable stocks all three families across the full distribution and transmission range:

• AAC overhead conductor: 56 codewords from Peachbell 6 AWG through Bluebonnet 3500 kcmil.
• AAAC overhead conductor: 14 codewords from Akron 30.58 kcmil through Greeley 927.2 kcmil.
• ACSR overhead conductor: 67 codewords from Turkey 6 AWG through Falcon 1590 kcmil.

Each product page lists the stranding and conductor material so you can confirm the codeword before requesting pricing. For the covered and insulated side of the utility line, the same category page carries triplex and quadruplex service drop and 15 kV primary URD.

Related Reading

• 15 kV Aluminum URD Cable: A Buyer's Specification Guide for the underground side of the same distribution system.
• Copper vs Aluminum Building Wire for the reasons aluminum dominates once the conductor leaves the building.
• Wire Weight Per Foot for reel-weight planning on large pulls.