Determining transmission line conductor condition and remaining life

Many overhead transmission lines in North America have exceeded their expected design life. It is therefore of interest to estimate the conditions and remaining lives of conductors in order to facilitate maintenance and capital replacement planning. Determining condition or health requires considerable investments. This report investigates whether visual inspection and age are sufficient parameters for estimating the remaining life of this asset. The simple visual and age assessment is quantified by means of Health Indexing. The effectiveness of this simple assessment is measured by comparing it to a condition evaluation that is based on detailed, quantitative laboratory testing. The use of life curves for different geographical regions facilitates the process of determining remaining life. Estimated lives based on the simple and more comprehensive assessments, as well as based on chronological age are compared for different geographical regions.