CABLE XPERTS

Overhead conductors

Application

Overhead conductors are used for the transmission and distribution of electrical power across long distances through overhead lines. They are widely used by utility companies and in rural electrification projects for low, medium, and high-voltage power distribution. These conductors are strung between poles or transmission towers and are exposed to various environmental conditions.

Conductor

Overhead conductors are typically made from aluminium, aluminium alloy, or aluminium reinforced with steel (e.g., ACSR – Aluminium Conductor Steel Reinforced). Aluminium is used due to its lightweight and good conductivity, while steel core reinforcement provides mechanical strength for longer spans and resistance to sag.

Insulation

Unlike underground or domestic cables, overhead conductors are usually bare, meaning they have no external insulation. Instead, they rely on air as the natural insulator. However, for low-voltage overhead lines near residential areas, aerial bundled cables (ABC) with insulation are used to prevent short circuits and improve safety.

Benefits

  • Cost-Effective: Cheaper to install and maintain than underground cables.
  • High Strength: Suitable for long spans and tough weather conditions.
  • Lightweight: Aluminium construction makes it easier to install over long distances.
  • Low Power Loss: Efficient transmission with minimal resistance in high-quality conductors.
  • Versatile: Available in different types (AAC, AAAC, ACSR, ACAR) for various mechanical and electrical requirements.

Marking

Overhead conductors may have tags or drum markings indicating the conductor type (e.g., ACSR Panther, AAAC Rabbit), size, strand configuration, manufacturer name, and standard (e.g., IEC, ASTM, BS). This information helps ensure proper installation and compliance with technical standards.

Types of Overhead Conductors

  • AAC (All Aluminium Conductor): Good conductivity, used in short spans.
  • AAAC (All Aluminium Alloy Conductor): Improved strength and corrosion resistance.
  • ACSR (Aluminium Conductor Steel Reinforced): High strength for long spans and heavy loads.
  • ACAR (Aluminium Conductor Alloy Reinforced): Combines conductivity and strength.