Abstract:
Die Erfindung betrifft eine Einrichtung zur Überwachung eines Leistungsschalters und einen Leistungsschalter, insbesondere für Niederspannungen, zur Unterbrechung eines durch einen Leiter (2) fliessenden Wechselstroms bei Überschreitung eines Strom-Grenzwerts mit Hilfe einer elektronischen Auslöseeinheit (1), mit einem am Leiter (2) angeschlossenen transformatorischen Stromwandler (3), insbesondere einen Eisenkernwandler, der primärseitig von dem Wechselstrom durchflossen wird und den Wechselstrom in einen Sekundärstrom wandelt, mit einem Brückengleichrichter (5), der zwei Eingänge (E1, E2) und zwei Ausgänge (A1, A2) aufweist, wobei der Stromwandler (3) an die beiden Eingänge (E1, E2) angeschlossen ist und der Brckengleichrichter (5) den Sekundärstrom in eine pulsierende Ausgangs-Gleichspannung umwandelt, die an einem Ausgang (A1) anliegt. Um eine einfache überwachung der elektrischen Verbindungen zwischen dem Stromwandler und der Auslöseeinheit auf Unterbrechung anzugeben, wird vorgeschlagen, dass ein Ausgang (A1) mit der pulsierenden Ausgangs-Gleichspannung jeweils für eine Zeit kurzgeschlossen wird und dass die Spannung, die sich bei nicht kurzgeschlossenem Ausgang (A1) an einem der beiden Eingänge (E2) einstellt, verwendet wird, um die elektrische Verbindung (VL) mit dem Stromwandler (3) zu überwachen.
Abstract:
A method of testing a short circuit protection system applied to a spur of an electric circuit, in which the short circuit protection system comprises a current limiting means which applies a current limit to said spur if the current thereon exceeds a spur current trip level, in which the electric circuit comprises a power supply and an isolation means adapted to fully or partially isolate the power supply from the electric circuit if the current thereon exceeds a power supply trip level for longer than a deadband period, in which said method comprises the following steps: i) applying a test current demand to said short circuit protection system which has a current and duration sufficient for said spur current trip level to be exceeded, but a current insufficient for said power supply trip level to be exceeded and/or a duration insufficient to exceed said deadband period, ii) detecting if the current limiting means applies said current limit or not during said test current demand.
Abstract:
An method for automatically testing an arc flash detection system by periodically or continually transmitting electro-optical (EO) radiation through one or more transmission cables electro-optically coupled to respective EO radiation collectors. A test EO signal may pass through the EO radiation collector to be received by an EO sensor. An attenuation of the EO signal may be determined by comparing the intensity of the transmitted EO signal to an intensity of the received EO signal. A self-test failure may be detected if the attenuation exceeds a threshold. EO signals may be transmitted according to a particular pattern (e.g., a coded signal) to allow an arc flash detection system to distinguish the test EO radiation from EO radiation indicative of an arc flash event.
Abstract:
At least one of input channel, containing information relative to a power system or a subpart of a power system is analyzed by a computation engine along with a test data channel. The results of the computation performed on the test data channel are compared against a predetermined test result, and if the two differ, a corrective action is taken.
Abstract:
A method of and an electrical fault monitoring apparatus for mon itoring an electrical load in an alternating current electrical installation are disclosed. An input terminal is connected to the electrical load to receive current/voltage input signals associated with the electrical load. A monitor in communication with the input terminal, monitors the input signals. An operator pre-defines threshold settings suitable for the particular load. A comparator is responsive to the monitor and compares the monitored input signals with the threshold settings and triggers an event if the monitored input signal violates a threshold setting. An output signal is then produced which activates ancillary equipment controlling the supply of power to the load. Tests are conducted at predetermined intervals and a record log is automatically kept of the tests done.
Abstract:
This invention relates to distribution line interrupting system having a remote auto alarm and a meter inspection function using communication network. This system comprise first and second current detectors for detecting the groundfault overcurrent, voltage detector, impedance detector, control unit and circuit breakers. The present system breaks only the line which has problems such as groundfault overcurrent and restore the line after the problems are solved.
Abstract:
A control device for controlling the opening/closing operation ofa switchgear, said control device comprising a control unit and an actuation chain. Its peculiarity consists of the fact that saidcontrol unit comprises electronic testing means for executing real-time tests of the operative efficiency of said actuation chain.
Abstract:
The present invention relates to a remote service system for a circuit breaker fixed in a remote allocation. Remote service is provided by any station that can be accessed through a communication network. The system is provided, on one side, with a diagnostic hand-held apparatus (3) known per se which is dedicated to a switch service and should be connected, if necessary, to a circuit breaker (1), through a connecting unit (2) provided to that end, and on the other side, with a telecommunication interface (5) for exchanging a data through a telecommunication network (6).
Abstract:
According to the invention, the retaining force of a permanent magnet, which forms part of the tripping magnet (11) in a circuit breaker forming part of a power switch (2) in a power supply circuit, is monitored, whereby the release coil of the tripping magnet (11) is energised with a pulse of current before a predicted response, whose duration is shorter than that duration necessary for the desired response.
Abstract:
The invention relates to a circuit arrangement for the monitoring of an electronic tripping device for low voltage switches with a microprocessor device which in connection with a digital-analog converter evaluates an overload current in such a way that mains tripping contacts disconnect the mains cables that are to be protected from the supply mains. The microprocessor device (MPE) presents a voltage crossover comparator (NDK) with which a testing constant-current impulse (KSI)can be transmitted via a current transformer auxiliary winding (SWZ) to the electronic tripping device (EAE) for amplitude measurement. Upon deviations of nominal value (new)compensation occurs or the mains tripping contacts (NAK)are activated by a corresponding alarm signal (ALS).