Patent ID: 8400740

Claim:
A limiting device for limiting a short-circuit current in an alternating-current low-voltage installation, including one or more supply lines having power-supply points with power-supply aggregates protected by feeder switches, the supply lines being separable at an isolating point into a first and a second line sections in response to a short circuit fault, each of the line sections including at least one power supply aggregate, the limiting device comprising: at least one polyphase high-speed short-circuiting device coupled to the isolating point, having a current carrying capacity sufficient for short-circuit current intensities occurring on the supply lines, the at least one high-speed short-circuiting device being configured to perform a short-circuit switching operation at the isolating point in response to a trip signal by contacting phases of the supply lines with each other; a first and a second power circuit breaker, respectively connected in series between the first and second the line sections and the high-speed short-circuiting device, the first and second power circuit breakers having a break time that is shorter than that of the feeder switches; and a respective current-sensing device coupled to each of the line sections, the current-sensing device being configured to detect a short circuit fault, and, in response thereto, transmit the trip signal to the at least one high-speed short-circuiting device so as to trigger the short-circuit switching operation.