What is the most common type of conductor?

• A. Aluminum wire
• B. ACSR or AAAC
• C. Copper wire
• D. Fiber optic cable

Answer: (B)

Overhead power conductors are chosen for a balance of conductivity, weight, and mechanical strength, so aluminum-based designs dominate. Aluminum conducts electricity reasonably well while being much lighter and far cheaper than copper, which makes it ideal for long spans and large networks. The steel-reinforced version uses a steel core to provide the necessary tensile strength for long transmission lines and heavy loads—this is the ACSR type. There’s also all-aluminum alloy conductors (AAAC) that skip the steel core but use strong aluminum alloys to maintain strength and improve corrosion resistance. Copper, although a better conductor, is heavier and far more expensive for long runs, and fiber optic cable is not a conductor at all. That combination of good conductivity with lower weight and cost, plus the required mechanical strength for long spans, makes ACSR or AAAC the most common choices.