SWITCHING DEVICE

PCT No. PCT/CH95/00010 Sec. 371 Date Nov. 20, 1995 Sec. 102(e) Date Nov. 20, 1995 PCT Filed Jan. 16, 1995 PCT Pub. No. WO95/22831 PCT Pub. Date Aug. 24, 1995A device for switching electric current includes a compressed gas switch, at least one vacuum switch, and two terminals. A first consumable contact of the compressed gas switch is electrically connected to a first of the two terminals and a movable electrode of the vacuum switch is connected to a second of the two terminals to form a quenching circuit. The two electrodes of the vacuum switch can be separated without the use of the drive and a contact pressure is applied to them which prevents the electrodes from breaking below a threshold value of the current to be switched off. On switch-off, the current to be interrupted is switched over from a rated current circuit containing two rated current contacts of the compressed gas switch to the parallel quenching circuit. The vacuum switch now in the quenching circuit breaks only if the current to be switched off exceeds the aforementioned threshold. As the vacuum switch does not conduct the rated current and, unlike the compressed gas switch, is involved only in a few break operations, it can be of substantially lighter construction than a vacuum switch carrying the rated current and is actuated in every switching operation.