The metallurgical significance of changes in production practices for overhead line conductor materials

Aluminium based overhead conductors are the primary means of transmitting and distributing power in the UK. The author draws attention to changes in the processing of the aluminium wires that go into these conductors that have occurred over recent years, and explains the metallurgical consequences of these changes and the significance for the user. Two types of aluminium based conductors are used: ACSR, in which hard drawn electrical conductor grade aluminium wires are reinforced with a steel core; and all aluminium alloy conductors, AAAC, made up entirely of aluminium alloy wires. The developments related to the production of the hard drawn aluminium and alloy wires are considered separately. In the case of the hard drawn aluminium wires, research work intended to reverse the decline in quality resulting from the changes in the production route is summarised and discussed