Dry Arc Resistance of Aged Polymer-Fiberglass Laminates

Arc resistance is a fundamental consideration with the use of polymer matrix composites as electrical insulation, particularly for applications with high voltage switching. However, engineering the arc resistance of composites remains a complex endeavor. Dry arc resistance in air of commercial fiberglass laminates FR5, G7, and GPO3 is compared. Aging, as one factor affecting dry arc resistance, is examined in this study. Ambient conditions at the material surfaces are maintained constant with minimal contamination. The ASTM test method D495 is generally followed, which is the application of timed current steps between two surface electrodes to determine the time to arc. Materials were characterized for polarization current normal to the surface prior to arc resistance testing. As compared to as received samples, a change in arc resistance with aging was not significant. However, clear difference in arc resistances between the laminate materials was determined, even without chemical contamination.