Results of indenter testing of in-plant and artificially aged cable specimens

The Indenter Polymer Aging Monitor (under license from the Electric Power Research Institute) is a nondestructive method of evaluating the aging of cable insulation and jacket material through measurement of compressive modulus. For many cable materials, modulus changes in an orderly manner related to the degree of aging. In this study, the usefulness of the Indenter as an in-situ test device was evaluated, and installed plant cable was tested. Additionally, an accelerated cable aging program was performed in order to develop life projection methodology. This paper summarizes the results from both the in-plant and artificial aging programs. These results indicate that the in-plant cables tested have aged little by comparison with the artificially aged specimens. Additionally, the study produced guidelines to support use of the Indenter system in field applications