Comparing investigations of the erosion phenomena on selected electrode materials in air and sulfurhexafluoride

The fundamental aim of this subject is to contribute a comparative analysis of stressing phenomena as a result of a switching arc in different media. The starting point of the study is to prove a definite high current stress on the contacts of high voltage disconnecters as they are applied in open air switch yards. The character of the alternating breaking arc and its effects has already been studied on different electrode materials in air. As the known present investigations of an evaluation of erosion in quantity will only succeed by means of empirical equations which contain specific factors of the device and the arrangement, the physical principles can be interpreted using the experiences of the former tests which were described with energy balances in the original papers some decades before. Through practical relevant switching experiments it is possible to arrange the experimental comparability regarding the effective erosion mechanisms. By that it is possible to define an energy balance of the short arc including the polarity influences on the electrode.