A device and method for reducing the risk of a streamer initiated flashover across a high voltage insulator under normal operating voltages. The device includes a support structure adapted to be grounded and mounted in proximity to the high voltage insulator; and space charge producing conductors wound around the support structure and forming coils for producing space charge in a proximity of an insulator to be protected, and inhibiting a formation of positive streamers, each conductor having a diameter not exceeding 0.1 mm for reducing a corona inception voltage of the support structure upon which each conductor is wound, in both dry and wet conditions.