Aluminium Conductor Steel Reinforced (ACSR) is the industry-standard composite conductor designed for overhead transmission and distribution lines. It combines the high electrical conductivity of outer EC-grade (1350-H19) aluminium wires with the superior mechanical tensile strength of a central high-strength galvanized steel core. This hybrid structure enables high voltage transmission across extended spans without excessive sag, drastically reducing structural tower costs while maintaining mechanical integrity under extreme weather loads, mechanical stress, and thermal expansion.
Technical Parameter Comparison Matrix
| Parameter | Standard ACSR (IEC 61089) | ACSR/AW (Aluminium-Clad Steel) | AAC (All Aluminium Conductor) | AAAC (All Aluminium Alloy) |
| Primary Core Material | Galvanized Steel Wire | Aluminium-Clad Steel Wire | None (1350-H19 Aluminium) | 6201-T81 Al-Mg-Si Alloy |
| Tensile Strength Ratio | High to Very High | High | Low | Medium-High |
| Corrosion Resistance | Moderate (Standard Zinc Coating) | Superior (Metastable Al Layer) | High | High |
| Conductivity (% IACS) | ~61% (Al Layer) / ~9% (Steel) | ~61% (Al Layer) / 14–20% (AW Core) | ~61% | ~52.5% |
| Maximum Span Capability | Long Spans (>300m) | Long Spans (Coastal/Industrial) | Short Spans (<100m) | Medium-Long Spans |
| Weight-to-Strength Ratio | Balanced | Optimized (Lighter than standard) | Heavy Sag under Tension | Low Weight, High Strength |
Key Mechanical and Electrical Performance Features
- High Strength-to-Weight Ratio: The high tensile strength steel core carries mechanical loads, allowing transmission towers to be spaced farther apart, reducing civil engineering costs.
- Thermal Expansion Resistance: Lower overall coefficient of thermal expansion compared to standard AAC conductors, keeping line sag minimal under heavy ampacity loads.
- Corrosion Protection Options: Available with light, medium, or heavy core greasing (-type greasing) according to IEC specifications to prevent internal core degradation.
- Vibration Suppression Compatibility: Easily fitted with Stockbridge-type vibration dampers and armor rods to dissipate wind-induced high-frequency Aeolian vibrations.