Abstract: A method for protecting against fault arcs in an electric power distribution system in which electric power from an electric power source is distributed via a common superordinate main distribution line and from the common main distribution line via multiple subordinate output lines. The main distribution line can be interrupted by a main switch, and each of the output lines can be interrupted by a paired output switch. When a fault arc is detected in the power distribution network based on electric voltage and/or current values in the main distribution line, a decision of whether to trigger a quenching process of the fault arc of the main switch or one of the output switches is made on the basis of voltage and/or current values in the output lines.

Abstract: In breaker devices an early short-circuit recognition is required and also a tripping of the contacts. The recognition of a short-circuit occurs so early that with consideration of the response time of the measuring probes and the unlocking mechanism by a suitable analysis algorithm the release of the movable contact occurs before or at least at the time that the current-breaking forces correspond to the contact force. The contact force is hence compensated for and a rapid opening of the contacts can be achieved.

Abstract: In breaker devices an early short-circuit recognition is required and also a tripping of the contacts. The recognition of a short-circuit occurs so early that with consideration of the response time of the measuring probes and the unlocking mechanism by a suitable analysis algorithm the release of the movable contact occurs before or at least at the time that the current-breaking forces correspond to the contact force. The contact force is hence compensated for and a rapid opening of the contacts can be achieved.

Abstract: The invention relates to a self-recovering current-limiting device with liquid metal. The device contains two solid metal electrodes (11, 12) which are rotationally symmetrical in relation to the longitudinal axis (3) of the current limiting device (1) and several compression chambers (4) which are partially filled with liquid metal (8) and arranged in a series between the electrodes (11, 12). The compression chambers are formed by pressure-resistant insulating bodies (5, 7) and insulating intermediate walls (6) which are supported by the same (6) and which have several connecting channels (9), distributed in a circular form. The aim of the invention is to extend the positions of use. To this end, the electrodes (11, 12) have cavities (14) which are connected to the adjacent compression chambers (4) by openings (16) and which are adequately wetted to completely filled with the liquid metal (8), according to the position of use.