5-35 kV medium voltage URD: state-of-the-art material evaluations using AEIC CS 5/6-87 qualification testing

The REA (Rural Electrification Administration) is currently using AEIC qualification testing as the substantial criterion for a cable manufacturer to receive approval of 15 kV and 25 kV cable designs. Through the utilization of existing industry standards, REA borrowers should be assured of cables of higher quality than those historically purchased. While higher approval standards should lead to increased cable life in general, each user has many cable decisions to make in order to select the approved cable that will best meet their needs. The authors propose a procedure to evaluate the available design and material alternatives. This procedure reveals that cable performance is more than just a function of the insulation material and indicates that a cable designed to accommodate projected field conditions can significantly improve both cable performance and economies. Cable design is shown to include the effect different material combinations can have on performance. It is concluded that an expanded evaluation and analysis of available test results by utilities should be a viable means of initiating continuous improvement in medium-voltage URD cables