HYDRO-QUEBEC CONCERNS RELATED TO PERFORMANCES OF SF6 CIRCUIT-BREAKERS

Hydro-Quebec's concerns regarding circuit-breaker reliability are pres ented. The first section focuses on two aspects crucial in determining line-charging-current breaking capacity: the arc duration and the tes t circuit configuration. The second part discusses the importance of m anufacturing quality for the arcing contacts, nozzles and gaskets. The third part, which is based on test results obtained for different bre akers, gives the test criteria at 20-degrees-C for simulating breaking tests at -50-degrees-C. Hydro-Quebec's requirements for testing the t ightness of SF6 breakers are set forth in the last section, together w ith a reliable leakage-measuring method.