The objectives of ampacity uprating (attractive conductor parameters for re-conductoring existing lines)

The ampacity of an overhead transmission line is simply defined as the maximum electrical current, which it can carry without either reducing the tensile strength of the conductor wires or exceeding the maximum sags beyond which minimum electrical clearances to ground and to other conductors are violated. In those lines for which it is not possible to increase the ampacity of an existing line by raising attachment points, re-tensioning the existing conductors, accepting a limited loss of conductor strength, and where it is not possible or economic to replace the line, line ampacity may be increased by replacing the original conductors ("re-conductoring"). In re-conductoring, it is usually economic to retain the existing structures or at least to minimize the degree to which they must be reinforced. As a result, conductors intended for re-conductoring may have different characteristics than those intended for use in new lines. The objective of this presentation is to define which conductor characteristics are most attractive in re-conductoring existing lines.