Arc mobility on new and eroded Ag/CdO and Ag/SnO2 contacts

The mobility of break arcs in a magnetic blast-field was investigated in both a model switch and a commercial contactor. After contact separation, three arc motion phenomena were measured independently: initial reduced arc motion (immobility and creeping), subsequent running, and final commutation from the contacts to the arc runners. Contacts made from Ag/CdO and from Ag/SnO/sub 2/ were compared in both new and eroded states. The results of erosion measurements under various stress conditions were consistent with the mobility phenomena observed.<
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