Restoration of dielectric properties in insulating liquids after an electrical arc

By the study of repetitive arcing in a quasi-uniform sphere-sphere electrical field configuration, we compared the ability of different liquids to restore in the millisecond range their insulating property after an electrical arc. With the help of an experimental apparatus based on the repetitive charging with a DC HV generator of negative polarity and discharging through an arc of a resistor-capacity system, the periodicity of arcing is adjustable. Typically, the time between two arcs is ≈10 ms. Different kind of liquids were tested: alkane, ester, alkyl benzene and polyaromatic types. We showed that the ester type presents the best restoration property after an electrical arc, which seems to be correlated to their well known arc extinguishing properties