VOLT-TIME CHARACTERISTICS OF SHORT ROD-ROD GAPS

In this paper volt-time or V-t characteristics for rod-rod air gaps ar e determined experimentally using positive and negative standard light ning impulses for gap spacings in the range of 5 to 25 cm. The rods we re of cylindrical shape with hemispherical ends and had tip radii in t he range of 1 to 5 mm. From the measurements, the effect of rod tip ra dius, gap spacing and impulse polarity on V-t characteristics is exami ned and empirical equations for predicting the V-t characteristics of short air gaps are proposed. The values of breakdown voltage predicted by the proposed equations are compared with measurements reported in the literature and a good agreement is observed between the two sets.