Influences of Contact Opening Speeds up to 200 mm/s and External Magnetic Field Application on Break Arc Duration Characteristics of AgSnO₂ Contacts in DC 14 V Load Conditions up to Around 10 A

Break operations of AgSn _O 2 contact pairs were conducted in dc inductive (L = 5.7 mH) and resistive load circuits at 14 V and up to around 10 A under different contact opening speeds from 0.5 to 200 mm/s and with/without external magnetic field application in air. Break arc voltage waveforms were observed, and total break arc durations and metallic phase durations were determined based on the observed arc voltage waveforms. After the experiments, averages for total arc durations as well as the metallic phase and gaseous phase (when observed) durations were calculated at each condition. The results show that increases in the contact opening speeds lead to reductions in metallic phase durations, while the application of external magnetic field causes gaseous phases to become shorter.