Experimental characterization of pre-strike arc duration of a MV-LBS using N2/CO2: influence of closing speed, pressure and mixing ratio

Short-circuit current making in a medium voltage load-break switch using N2/CO2 is expected to result in longer pre-strike arcs compared to SF6, due to lower dielectric strength, leading to increased contact degradation. Measures to limit impact of pre-strike arc on the contact system are needed. This paper aims to experimentally investigate the influence of closing speed, filling pressure and mixing ratio on pre-strike arc duration towards increasing contact system life time.