AAAC - All Aluminium Alloy ConductorsAAAC, which has been in use for several decades abroad, has been adopted now in India as well. The alloy is based on Aluminum - Magnesium - Silicon System (Al-Mg-Si). Aluminum Alloy Conductor is a generic name rather than the name of a particular conductor. The group generally includes: AAAC - High strength comprising heat treatable aluminum alloy wires AAAC - High Conductivity comprising of heat treatable aluminum alloy wires Aluminum Conductor Alloy Reinforced comprising of EC grade aluminum wires and high strength aluminum alloy wires with adequate conductivity Aerially Bunched Conductors comprising of compacted, bare-insulated, high strength aluminum alloy conductor as neutral messenger wire bunched with three to five insulated EC grade aluminum phase conductors and lighting conductors. ADVANTAGES OF AAAC 1. CORROSION RESISTANCE: AAAC exhibits excellent corrosion resistance especially in coastal and polluted industrial areas due to absence of steel core. 2. LOWER POWER LOSSES: Since AAAC is homogeneous (with all strands of Aluminum Alloy) with no steel component, its resistance is lesser in comparison to that of ACSR of same size. 3. HIGHER AMPACITY: AAAC can carry at least 15-20% extra current as compared to ACSR of same size. 4. LONGER LIFE: Experience in foreign countries shows that All Aluminum Alloy Conductors are in service for more than 60 years, which is about twice the life of ACSR Conductors. 5. SURFACE HARDNESS: The surface hardness of AAAC is 80 BHN as compared to 35 BHN of ACSR. This reduces damage to its surface while handling, and therefore it leads to lesser corona losses and radio interference at EHV. 6. THERMAL STABLITY: AAAC are stable up to 90˚C against ACSR which are stable up to 75˚C. 7. HIGHER STRENGTH TO WEIGHT RATIO: Since AAAC has higher strength to weight ratio, span can be increased from 2 to 15% resulting in overall reduction of cost in towers / supports and other accessories in transmission line systems. PHYSICAL PROPERTIES OF AAAC WIRES: Melting Temperature : 662˚C Density : 2.7 kg/dm³ Co-efficient of Linear Expansion per ˚C : 23 x 10-6 Brinnell Hardness : 80 BHN Electrical resistivity at 20˚C Standard : 0.0325 ohm-mm²/m Maximum : 0.0328 ohm-mm²/m Elongation : Min. 4% (present in 200 mm) Electrical conductivity at 20˚C In Percentage IACS Standard : 53.0 Minimum : 52.6 Ultimate Tensile Strength (Minimum) : 31.5 kg/ mm² Modulus of elasticity in kg/ mm² Initial : 5200 to 5600 Final : 6250 to 6450