AAAC-IEC61089
AAAC All Aluminium Alloy Conductor to IEC 61089 / ASTM B399
A 6201-T81 alloy conductor that nearly doubles the tensile strength of AAC at the same diameter, with no steel core to corrode.
AAAC exists because annealed aluminium is too soft for a long span. Heat-treating an aluminium-magnesium-silicon alloy to the T81 temper lifts the tensile strength to roughly twice that of 1350-O, so the same diameter strings a longer span or survives a heavier ice load. The electrical cost is conductivity: the A2 alloy sits near 52.5% IACS rather than 61%, which means slightly more resistance for the same cross-section.
What AAAC avoids is the thing that limits ACSR. There is no steel core, so there is no zinc to lose in a coastal or industrial atmosphere and no bimetallic couple inside the conductor. For a distribution utility working in a marine or chemically aggressive environment, that removes a maintenance item. Voltcore supplies AAAC to IEC 61089 and to ASTM B399 in 25 mm² to 1000 mm².
Specification
| Item | Value |
|---|---|
| Type | All aluminium alloy concentric lay stranded conductor |
| Alloy and temper | 6201-T81 aluminium-magnesium-silicon, heat treated |
| Area range | 25 – 1000 mm² |
| Stranding | 7, 19, 37, 61 wires depending on size |
| Conductivity | 52.5% IACS nominal |
| Resistivity at 20 °C | 32.530 nΩ·m for the A2 alloy |
| Typical tensile strength of wires | 295 MPa minimum for 6201-T81 |
| Maximum operating temperature | +90 °C continuous |
| Density used for mass | 2.70 g/cm³ |
| Linear expansion coefficient | 23 × 10⁻⁶ /K |
| Standard | IEC 61089, ASTM B399 |
| Supply form | Wooden drums with steel-tyred flanges, lengths to 4000 m |
Layer-by-layer construction
Listed from the conductor outward. Read this alongside the specification table — the two together tell you whether the cable will survive its installation method.
- 1. Centre wireSingle 6201-T81 alloy wire, heat treated and cold worked
- 2. First layer6 alloy wires laid over the centre wire
- 3. Outer layers12 to 24 further alloy wires, lay direction reversed between successive layers
- 4. Lay and finishConcentric lay to IEC 61089, lay ratio 10 to 14 on the outer layer, clean bright surface
- 5. PackingContinuous length on a wooden drum with steel-tyred flanges, sealed and tagged with size, length and alloy
Reference dimensions and weights
| Nominal area (mm²) | Stranding (alloy wires × mm) | Approx. overall diameter (mm) | Approx. mass (kg/km) | Rated breaking load (kN) | Max. DC resistance at 20 °C (Ω/km) |
|---|---|---|---|---|---|
| 25 | 7 × 2.15 | 6.4 | 69 | 7.0 | 1.30 |
| 35 | 7 × 2.52 | 7.6 | 96 | 9.8 | 0.929 |
| 50 | 7 × 3.00 | 9.0 | 138 | 14.0 | 0.651 |
| 70 | 19 × 2.15 | 10.7 | 193 | 19.6 | 0.465 |
| 95 | 19 × 2.52 | 12.6 | 262 | 26.6 | 0.342 |
| 120 | 19 × 2.85 | 14.2 | 330 | 33.6 | 0.271 |
| 150 | 19 × 3.15 | 15.8 | 413 | 42.0 | 0.217 |
| 185 | 37 × 2.52 | 17.6 | 509 | 51.8 | 0.176 |
| 240 | 37 × 2.85 | 20.0 | 661 | 67.2 | 0.136 |
| 300 | 37 × 3.20 | 22.4 | 826 | 84.0 | 0.108 |
Reference figures for preliminary sizing and drum planning. Overall diameter and weight vary with strand construction and sheath thickness tolerance; certified drawings are issued with each quotation.
Engineering characteristics
- 6201-T81 alloy gives close to twice the breaking load of AAC at the same diameter.
- No steel core, so there is no zinc to lose and no bimetallic corrosion inside the conductor.
- Resistance at 32.530 nΩ·m is higher than AAC, and the size should be chosen on the drop it implies.
- Concentric-lay stranding in 7, 19, 37 or 61 wires, to IEC 61089 and ASTM B399.
- Breaking load tabulated per size in kN for a sag-tension calculation on the ruling span.
- Lighter per metre than ACSR of the same diameter, which reduces the pole loading.
- Suited to coastal and industrial atmospheres where a galvanised steel core would need inspection.
Typical applications
- Medium and long distribution spans where AAC would sag too far
- Coastal and marine-adjacent distribution networks
- Rural electrification with wide pole spacings
- Sub-transmission lines up to 132 kV
- Re-conductoring of existing lines to raise ampacity without a stronger tower
Ordering options
- 25–1000 mm² in 7, 19, 37 and 61 wire strandings
- IEC 61089 or ASTM B399 designation on the drum tag
- Drum lengths to 4000 m, packed to a stringing schedule
- Grease-coated construction for severe industrial atmospheres
- Drum stencilling with the buyer's project reference
Standards manufactured to
- IEC 61089
- ASTM B399
- IEC 60889
Manufactured to other standards on request. Send the standard number with your RFQ and we will quote against it rather than against a near-equivalent.
Price and availability for AAAC All Aluminium Alloy Conductor
Include cross-section, core count, voltage grade, route length and installation method — those five determine price more than anything else on the page.
- Engineer-reviewed before pricing
- Reference drawings issued with the quotation
- Free sample up to free sample up to 5 m
AAAC All Aluminium Alloy Conductor — frequently asked questions
AAAC or ACSR for a 200 m span?
Both will work mechanically, so the choice is the environment and the lifecycle. AAAC gives you a single metal with no steel to corrode and a slightly lighter conductor. ACSR gives a higher breaking load for the same diameter and a lower price per metre. On a coastal or industrial route AAAC is usually the better whole-life decision; inland on a long span, ACSR.
Does the lower conductivity of AAAC matter?
It shows up as resistance, not as a fault. At the same cross-section AAAC runs about 15% more resistance than AAC, so if your line is long and the drop is near its limit you either accept the extra loss or move up one size. The saving on poles and on maintenance usually outweighs it, but the calculation should be done on resistance, not on area.
What is the ASTM equivalent of AAAC?
ASTM B399 covers the 6201-T81 concentric-lay aluminium-alloy conductor, and it is the designation North American specs use. IEC 61089 covers the same construction under the A2 alloy designation. Voltcore supplies to either, and will mark the drum tag with the code the project document names.
Can AAAC replace an existing AAC line on the same towers?
Usually yes, and that is a common re-conductoring job. AAAC of the same diameter is roughly the same weight and stronger, so the tower loading is comparable. The checks to make are the sag at the higher stringing tension and the tension limit of the existing fittings. Send the span and the current conductor and Voltcore will tabulate the comparison.