The primary types of conductors used in overhead transmission lines are designed to balance electrical conductivity, mechanical strength, and cost-effectiveness. The most common types include:

• AAC (All-Aluminum Conductor): Made solely of aluminum, these are lightweight and have good conductivity, but are often used for distribution rather than high-voltage transmission due to their lower strength.

• AAAC (All-Aluminum Alloy Conductor): Made from high-strength aluminum alloys, these conductors offer better strength-to-weight ratio and improved sag characteristics compared to AAC.

• ACSR (Aluminum Conductor Steel Reinforced): This is the most widely used type for overhead transmission lines. It consists of a central core of steel strands for high tensile strength, surrounded by layers of aluminum wires for excellent conductivity. This combination allows for long spans with less sag, making it ideal for high-voltage applications.

• ACSS (Aluminum Conductor Steel Supported): A newer type of conductor where the steel core supports the entire mechanical load. This allows the aluminum strands to operate at higher temperatures without losing strength, resulting in lower sag and a higher current-carrying capacity (ampacity).