Make erosion on Ag/SnO/sub 2/ and Ag/CdO contacts in commercial contactors

This paper is a continuation of previous investigations of the different arc erosion of contacts made from Ag/CdO or Ag/SnO/sub 2/ when stressed according to IEC duties AC3 and AC4, respectively. While preceding studies dealt with break erosion, this work considers contact bounce and make erosion only. Preliminary measurements showed that the bounce amplitudes of modern contactors are merely on the order of 0.1 mm. Under these conditions Ag/SnO/sub 2/ suffered two to three times higher arc erosion losses at make than Ag/CdO did. The influence of various parameters was studied in order to obtain better insight into the erosion mechanism.<
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