No abstract

This present work was a comparison of positive DC breakdown voltage obtained by "multiple level test" and "successive discharge test" methods following IEC 60-1 (1989) of a sphere-sphere gap in air. The experiment was done under actual different atmospheric condition, temperature and absolute humidity. The ratio of absolute humidity to the air density correction factor, h/Ɂ, was in the range of 7-13 g/m 3 . The diameters of the sphere were 12.5 cm and 5 cm. The results found that the breakdown voltages obtained by multiple level and successive discharge methods were very close. The average difference of breakdown voltages from these 2 methods for 12.5 cm and 5 cm sphere was 1.33% and 1.05% respectively.