Influence of Air Gap Characteristics on Line-to-Ground Switching Surge Strength

A series of tests, carried out by applying impulse waves simulating switching surges to air gaps with electrodes of different shapes, is described. From the test results, it has been possible to draw some important conclusions about the influence of the electrode shape and also to single out simple rules for the predetermination of the behavior of air insulation; these rules can be particularly useful for designing purposes.