SWITCHING APPARATUS AND ACTIVATION SUPPRESSION METHOD FOR ELECTRIC CONTACT

摘要

The invention provides a switching apparatus wherein the life and the reliability of an electric contact are improved by fundamentally suppressing formation of black powder and activation of the surface of the contact by a chemical reaction. Microcapsules in which organic acid or organic acid precursor from which organic acid is produced as time passes is enclosed are placed into the internal space of an enclosed case so that organic compounds produced on and in the proximity of contact surfaces is oxidized with organic acid which escapes from the microcapsules and vaporized in the enclosed case without forming a film on the surfaces of the contacts to suppress activation of the surfaces of the contacts.