What is the size of GNAT conductor?

7/2.59 mm Al — 36.88 mm² of aluminium, 36.88 mm² total, with an overall diameter of 7.77 mm.

What is the weight of GNAT conductor per km?

101 kg per km, so a 1 km drum weighs about 0.10 tonnes.

What is the resistance of GNAT conductor?

0.7967 Ω/km DC at 20 °C. At 75 °C the AC resistance rises to roughly 1.0220 Ω/km once skin effect is included.

AAC conductor · 35 mm² nominal

GNAT Conductor — Specification & Current Carrying Capacity

Q: What is the current carrying capacity of GNAT conductor?

About 160 A. That figure assumes 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).

7/2.59 mm Al · 36.88 mm² total area · 7.77 mm overall diameter · 101 kg/km · 0.7967 Ω/km at 20 °C · 6.10 kN breaking load · about 160 A.

LT distribution and coastal areas where steel corrosion is a concern.

Calculate GNAT ampacity Compare with other conductors

Full technical specification

Data basis: IS 398 and standard manufacturer catalogues. Individual manufacturers vary slightly — confirm against the supplier datasheet before final design.

Code name	GNAT
Family	AAC
Material	All-aluminium stranded conductor (no steel core)
Stranding	7/2.59 mm Al
Aluminium strands	7 × 2.59 mm
Steel strands	None
Aluminium area	36.88 mm²
Steel area	—
Total area	36.88 mm²
Nominal (trade) area	35 mm²
Overall diameter	7.77 mm
Approximate weight	101 kg/km
DC resistance at 20 °C	0.7967 Ω/km
Calculated AC resistance at 75 °C	1.0220 Ω/km
Ultimate breaking load	6.10 kN
Current carrying capacity	160 A (standard basis)

Construction of GNAT

GNAT is built as 7/2.59 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 36.88 mm² and overall diameter of 7.77 mm set both the resistance and the wind/ice loading the structures must carry.

Where GNAT is used

LT distribution and coastal areas where steel corrosion is a concern. At 160 A on the standard basis, a three-phase circuit of GNAT carries roughly 3 MVA at 11 kV, 9 MVA at 33 kV and 37 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 GNAT from 157 A to 78 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.

Other AAC conductors

ANT

7/2.21 mm Al · 130 A

WASP

7/3.40 mm Al · 225 A

Calculators for this conductor

Conductor Current Capacity Calculator

Recalculate GNAT ampacity for your own weather and temperature limit.

Voltage Drop Calculator

Check the drop over the span length you are planning.

AWG to sq mm Converter

Translate the area into American gauge sizes.

Transformer Sizing Calculator

Match the feeder to the transformer it supplies.

AC Cable Sizing Calculator

For the insulated cable portions of the same circuit.

Wire Gauge Chart

AWG to mm² reference table.