Relationship between Arc Duration and Motion of Arc Spots for Break Arcs of Ag and Ag/ZnO Electrical Contacts

Junya SEKIKAWA  Takumi SUGIO  Takayoshi KUBONO  

IEICE TRANSACTIONS on Electronics   Vol.E91-C   No.8   pp.1249-1254
Publication Date: 2008/08/01
Online ISSN: 1745-1353
DOI: 10.1093/ietele/e91-c.8.1249
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Recent Development of Electromechanical Devices(Selected Papers from IS-EMD2007))
Category: Arc Discharge & Related Phenomena
arc discharge,  electrical contact,  break arc,  high-speed camera,  Ag/ZnO,  

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Break arcs are generated in a DC 42 V-10 A resistive circuit. The contact material is Ag or Ag/ZnO. The number of break operations is two hundreds for each contact material. The motion of break arcs is observed with a high-speed camera. Relationship between the dependence of arc duration on the number of operations and the motion of arc spots is investigated. The following results are shown. For Ag contacts the arc duration is almost constant independent to the number of break operations. For Ag/ZnO contacts, on the other hand, the arc duration changes irregularly to short (59 ms) or long (69 ms) arc-duration after 30th break operation. The moving range of arc spots on contact surfaces is broad for the case of short arc-duration and is narrow for the case of long arc-duration. The cause of the results for Ag/ZnO contacts is considered that the difference of the boiling points of Ag and ZnO leads to the porous structure on the contact surface.