Data basis: IS 398 and standard manufacturer catalogues. Individual manufacturers vary slightly — confirm against the supplier datasheet before final design.
Code name
ANT
Family
AAC
Material
All-aluminium stranded conductor (no steel core)
Stranding
7/2.21 mm Al
Aluminium strands
7 × 2.21 mm
Steel strands
None
Aluminium area
26.85 mm²
Steel area
—
Total area
26.85 mm²
Nominal (trade) area
25 mm²
Overall diameter
6.63 mm
Approximate weight
74 kg/km
DC resistance at 20 °C
1.0930 Ω/km
Calculated AC resistance at 75 °C
1.4020 Ω/km
Ultimate breaking load
4.60 kN
Current carrying capacity
130 A (standard basis)
Construction of ANT
ANT is built as 7/2.21 mm Al. All-aluminium stranded conductor (no steel core). With no steel core the whole cross-section conducts, giving the lowest resistance per mm² of any of the families, at the cost of breaking load. The total metallic area of 26.85 mm² and overall diameter of 6.63 mm set both the resistance and the wind/ice loading the structures must carry.
Where ANT is used
Short LT spans and urban distribution where corrosion resistance matters. At 130 A on the standard basis, a three-phase circuit of ANT carries roughly 2 MVA at 11 kV, 7 MVA at 33 kV and 30 MVA at 132 kV — useful as a first sanity check before detailed load flow.
Conditions behind the current rating
Ambient 40 °C, maximum conductor temperature 75 °C, cross-wind 0.61 m/s, solar radiation 1000 W/m², emissivity 0.9, absorptivity 0.8, outdoor overhead installation (IEEE 738 / IS 398 practice).
Wind is the single biggest variable. Removing it drops the rating of ANT from 129 A to 63 A in the cases above.
Raising the permitted conductor temperature increases the rating, but sag and long-term annealing of the aluminium set the practical ceiling — 75 °C continuous is the usual limit.
A weathered, dark conductor absorbs more sunlight but also radiates heat better; the standard 0.8 absorptivity / 0.9 emissivity pair is the conservative combination.
Terminations, jumpers and clamps often limit a line before the conductor does. Check the whole current path, not only the span.