Vacuum Contacts Conditioning by a Glow Argon Discharge Using AC Power Source

Before proceeding to high-current tests of vacuum interrupters (VIs), the vacuum contacts are usually subjected to a first conditioning process. In a vacuum vessel, the industrial conditioning process consisting in heating the contacts and sealing the VI under ultrahigh vacuum is not suitable. As an alternative, argon glow discharge activated by an ac power source is used for contact cleaning. This first conditioning step is applied to remove organic and metallic oxide contaminations and also adsorbed molecules like oxygen. This can improve the vacuum quality and reduces the effect of the impurities present at the contact surface on the arcing phase during high-current interruption tests.