Electrical performance of cycloaliphatic epoxy materials and insulators for outdoor use

This paper reports the results of material tracking and erosion tests, and flashover tests of full-scale insulators made from epoxy compounds. Six dif ferent formulations, all based on the cycloaliphatic epoxy family, were eva luated as flat slabs and complete insulators rated for 25 kV (line to line) system voltage, In addition, line insulators in the range 11-66 kV that ha d been operating satisfactorily for several Sears in light to heavy contami nated regions in different countries, were evaluated to obtain information on their future expected performance, Material tracking and erosion tests w ere performed using the standard ASTMD-2303 Inclined Plane (IP) test, and a variation of the same test that was developed in-house. Flashover tests we re performed using the IEC Standard 507 "Clean-Fog" method. Results demonstrate that all material formulations evaluated had adequate t racking and erosion resistance for outdoor use. In addition, the insulators evaluated did not flashover at nominal service voltage land higher) under a wide range of simulated contamination conditions. The overall good perfor mance of the insulators has been related to material formulation, design an d manufacturing of the insulators.