Patent ID: 7334319

Claim:
A method for opening a contact gap in a vacuum interrupter, which operates at a voltage of at least 12 kV and which has two switching contact pieces in a housing, which switching contact pieces can move relative to one another and are electrically connected to an exterior via current supply bolts, comprising: moving the contact pieces at a first speed to a contact separation of about ¼ to ½ of a predetermined final separation, in a first phase of the disconnection movement used for current quenching; moving the contact pieces at a second speed to a predetermined final separation, with the first speed being at least three times greater than the second speed, in a second phase of the disconnection movement used for voltage isolation; fitting the vacuum interrupters with axial magnetic field contacts and operating the vacuum interrupters at a voltage of more than 52 kV, and the first speed being about 1 to 3 m/s and the second speed being about 0.1 to 0.3 m/s; and moving the two switching contact pieces in opposite senses, with the first switching contact piece being moved at the first speed during the first phase of the disconnection movement, and the other switching contact piece being moved at the second speed during the first and the second phase of the disconnection movement.