Restoration of the insulation of ice-covered post insulators

This article describes a technique used to deice and restore the external insulation of post insulators covered with ice in the process of melting. Tests were done in the large environmental chamber at Université du Québec à Chicoutimi's research pavillion on atmospheric icing. Post insulators were covered with ice and subjected to conditions close to the electrical flashover. The surface of the post insulators was cleaned with a powerful steam jet. This considerably reduced the leakage currents and, as a result, the insulation of the post insulators could be restored. The improvement of the insulation was estimated based on a simple model where the arc is propagated on a polluted surface.