Abstract: The invention is a condition monitor for a switchgear device in an electrical power distribution system. The switchgear device is arranged with an electrically powered actuator for operating a moveable part of the switchgear device, for example, operating the opening and/or closing of a circuit breaker. The switchgear device has a control unit with means to receive state information from the actuator, and panel means to present information via an HMI. The HMI may be accessed remotely. In other aspects of the invention a method, a human-machine interface and a computer program for carrying out the method are described.

Abstract: The invention is a condition monitor for a switchgear device in an electrical power distribution system. The switchgear device is arranged with an electrically powered actuator for operating a moveable part of the switchgear device, for example, operating the opening and/or closing of a circuit breaker. The switchgear device has a control unit with means to receive state information from the actuator, and panel means to present information via an HMI. The HMI may be accessed remotely. In other aspects of the invention a method, a human-machine interface and a computer program for carrying out the method are described.

Abstract: A fault current limiter in which a resistor is inserted by a running arc. The arc is allowed to burn in a commutating unit until the current zero-crossing. Upon the passage through zero the arc is extinguished and the current is commutated to a shunt resistor. The commutating unit comprises a gap-formed nozzle, in which the arc is burning. The nozzle is defined by two nozzle halves of a material which gives off gas under the influence of the arc. Close to the nozzle inlet is a pressure accumulating chamber, in which an overpressure is built up during the arcing time. After current zero-crossing, the hot arc residues are effectively vented by means of the overpressure in the pressure accumulating chamber. For cooling the gas in the chamber and for guiding the gas flow, the chamber is divided into small sub-volumes defined by metal plates.

Abstract: A fault current limiter according to the invention comprises a contact device (K) to the contacts of which is connected a resistor/inductor combination comprising a series connection of a first (R1) and a second (R2) resistor as well as a third resistor/inductor (R3) connected in parallel with the series-connected resistors. The second resistor consists of a resistor with superconducting properties, dimensioned such that the change from superconducting to normally-conducting state occurs when the critical current density of the resistor is attained.

Abstract: A current limiter for high voltage utilizes the high migration velocity of an arc for rapidly inserting at least one pair of resistive runner rails upon a short-circuit in a circuit. To be able simultaneously to fulfil the demands for a high energy absorption capacity and sufficient resistance per unit of length of the runner rails, the runner rails are made of a relatively thin, insulated tape of an electrically conductive material, which is folded and packed to form a solid resistance package. Between the two runner rails in each pair of rails there extend two parallel walls of insulating material, which form between them a narrow gap for the arc. The magnetic field in the gap is reinforced with the aid of a magnetic core and/or current loops.