This paper describes the dielectric and accelerated aging tests on a 800-kV ac PPLP-insulated low-loss SCFF cable prototype. The test program was developped to validate the PPLP technology for future Hydro-Quebec 765 kV St-Lawrence under-river crossings. The paper reports on the cable and accessories characteristics, the test line construction, the test program, and the main results obtained. The successfully completed program has shown the overall very good performance of the cable and its accessories.