Conductors for power transmission

The major types of conductors used in power transmission are aluminium conductor with steel reinforced (ACSR), copper, cadmium copper, phosphor bronze and galvanized steel. ACSR conductors have many advantages. The strength of ACSR conductors is generally 50% greater than that of equivalent copper conductor. Life span is longer and has less sag compared to copper conductor. This is attributed to its high tensile strength. In a high voltage line, corona loss for ACSR conductor is found to be very less. This is due to the large diameter of the ACSR conductor. ACSR conductor is cheaper than copper conductor. Cadmium copper is preferred when a power transmission line of small cross-section and longer spans are required. If the atmosphere contains harmful gases like ammonia, phosphor bronze can be used. The two parameters that affects the span length of transmission are voltage and maximum tension on the pole.