Abstract: A DC switching device including a plurality of arc-extinguishing chambers and a plurality of contacting units conductively connected in series to each other, each of the contacting units including a stationary contact and a movable contact movable between a rest position and a working position, an air gap is formed between the contacts when the movable contact is moved from the working position to the rest position and each of the chambers enclosing a contacting unit and including a splitter plate unit including one or more splitter plates arranged for splitting and cooling an arc occurring in the air gap between the contacts. The chambers include a permanent magnet for generating a magnetic field between the contacting unit and the splitter plate unit and the splitter plates are made of non-ferromagnetic material, and the splitter plates of the chambers are made of ferromagnetic material.

Abstract: A DC switching device including a plurality of arc-extinguishing chambers and a plurality of contacting units conductively connected in series to each other, each of the contacting units including a stationary contact and a movable contact movable between a rest position and a working position, an air gap is formed between the contacts when the movable contact is moved from the working position to the rest position and each of the chambers enclosing a contacting unit and including a splitter plate unit including one or more splitter plates arranged for splitting and cooling an arc occurring in the air gap between the contacts. The chambers include a permanent magnet for generating a magnetic field between the contacting unit and the splitter plate unit and the splitter plates are made of non-ferromagnetic material, and the splitter plates of the chambers are made of ferromagnetic material.

Abstract: A current-limiting device comprises at least one polymer-based electrically conducting body with two contact surfaces and at least two electrodes. Close to a first one of the two contact surfaces of the polymer-based electrically conducting body, a surface layer is arranged. The resistivity of the surface layer is reduced relative to the resistivity of the bulk of the polymer body, and at the same time at least the second contact surface of the body is adapted to make free contact with at least one of the electrodes or other electrically conducting body.