摘要:
Dispositif de mesure électrique pour mesurer la résistance d'une prise de terre d'une installation électrique. L'invention concerne un dispositif et un procédé de mesure électrique. Le dispositif comporte au moins : -une première liaison (PE) à une prise de terre des masses (Ra) d'une installation électrique (INS); -une deuxième liaison (CN) à un conducteur de neutre (LN); -un générateur de courant alternatif (GEN); -une unité de contrôle (UC) adaptée pour: o commander au générateur d'injecter du courant alternatif sur la prise de terre des masses; o mesurer, entre lesdites première et deuxième liaisons, une tension générée par ledit courant injecté; o déterminer une résistance de la prise de terre des masses en fonction du courant injecté et de la tension mesurée; o émettre une première consigne d'alerte lorsque ladite résistance comparée dépasse ledit seuil prédéterminé.
摘要:
In an embodiment, a missing utility ground detection circuit includes a pair of balanced resistors each connected to receive utility voltage from a different one of a pair of utility power lines, the balanced resistors being connected together at a summing node to be capable of summing the voltages from the pair of utility power lines. It includes an unbalance resistor connected to shunt voltage from one of the utility power lines. It has a summing amplifier with an input coupled to the summing node and to a reference voltage, and an input coupled to a second reference voltage. It has an averaging circuit connected at the output of the summing amplifier. A comparator is provided having an input connected to the averaging circuit an input connected to a threshold voltage.
摘要:
The invention relates to an apparatus (1) for controlling and regulating a DC voltage converter (2), comprising one or more power output stages and a control unit (4) with a signal ground line (4.1) which have a common ground potential (M). A switch (5) for electrically disconnecting the signal ground line (4.1) is provided according to the invention, wherein the switch (5) is opened when the DC voltage converter (2) is active and the switch (5) is closed when the DC voltage converter (2) is inactive.
摘要:
A method for detecting predetermined fault conditions associated with the supply of AC electrical power to a consumer, the supply having an active conductor and a neutral conductor with the neutral conductor being connected to earth. The method comprises providing a first current detector associated with the active conductor; providing a second current detector associated with the neutral conductor; providing a voltage detector to detect voltage between the active conductor and the neutral conductor; and checking a current ratio of neutral current to active current whereby the current ratio is indicative of a predetermined fault condition. Also disclosed is a method of checking the condition of supply line active and neutral conductors in a consumer's supplied premises including determining the impedance of the active conductor and the impedance of the neutral conductor to indicate the condition of each of the active and neutral conductors.
摘要:
Certain exemplary embodiments comprise an electrical power distribution panel, which can comprise a Source Line Evaluation Detector. The Source Line Evaluation Detector can be configured to open a contactor responsive to at least one condition from a plurality of monitored electrical source line conditions. The Source Line Evaluation Detector can be configured to monitor the one or more monitored electrical source line conditions.
摘要:
A receptacle for a power circuit includes a receptacle housing, a line terminal structured to receive a voltage including one of a nominal voltage and a greater excessive voltage, a load terminal, a neutral terminal, a load neutral terminal, separable contacts electrically connected between the line and load terminals, an operating mechanism structured to open and close the separable contacts, and a trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The trip mechanism includes a trip circuit structured to detect a first trip condition associated with the power circuit and to responsively actuate the operating mechanism to trip open the separable contacts. The trip mechanism also includes an overvoltage circuit structured to detect a sustained excessive voltage condition between the at least one neutral terminal and the line or the load terminals and to responsively actuate the operating mechanism to trip open the separable contacts.
摘要:
A control system for bathers includes an electronic controller which controls operation of an electric heater assembly connected in a water flow path for heating water. The heater assembly includes a heater housing and electric heater element. A solid state water temperature sensor apparatus provides electrical temperature signals to the controller indicative of water temperature at separated first and second locations on or within the heater housing. The presence of water in the heater housing is detected electronically, by turning on the heater, and monitoring the temperature sensors for unusual temperature rises or other faults for a period of time thereafter. A solid state water presence sensor apparatus can also be used to determine the presence of water within the heater housing, providing electrical water presence signals to the controller indicative of the presence or absence of a body of water within the heater housing. An independent circuit apparatus is connected to the water temperature sensor apparatus and to a power relay, automatically causing high voltage power to be disconnected from the heater assembly when the water temperature exceeds a predetermined temperature. The independent circuit apparatus requiring a manual reset once the water temperature has dropped below a predtermined level to allow the high voltage power to be reconnected to the heater assembly. The system includes ground continuity detection, ground current detection and ground fault detection circuits.
摘要:
Embodiments of the invention provide a variable frequency drive system and a method of detecting a ground in a system having a pump driven by a motor. The drive system and method can provide one or more of the following: a sleep mode, pipe break detection, a line fill mode, an automatic start mode, dry run protection, an electromagnetic interference filter compatible with a ground fault circuit interrupter, two -wire and three- wire and three-phase motor compatibility, a simple start-up process, automatic password protection, a pump out mode, digital input/output terminals, and removable input and output power terminal blocks.
摘要:
A device for monitoring a neutral grounding resistor (NGR), including first and second NGRs electrically connected in parallel, a rectifier circuit electrically connected in series with the second NGR and a voltage source and a logic resistor electrically connected in series with the second NGR. A logic circuit measures current passing through the logic resistor and determines the resistance of the first NGR based on the measured current and the resistance of the second NGR. As such, a failed-open or failed-short condition of the first NGR may be identified based at least in part on the determined resistance of the first NGR.
摘要:
Bei einer Detektoreinheit (1) zum Erkennen einer Neutralleiterunterbrechung in einem symmetrischen Mehrphasenstromnetz (2) mit wenigstens einem ersten Außenleiter (L1), einem zweiten Außenleiter (L2) und einem Neutralleiter (N), wird zur einfachen Erkennung einer Neutralleiterunterbrechung in einem symmetrischen Mehrphasenstromnetz vorgeschlagen, dass die Außenleiter (L1, L2) jeweils mittels Stichleitungen (3, 4) selber Impedanz mit einem Sternpunkt (6) verbunden sind, und dass die Detektoreinheit (1) wenigstens einen ersten Sensor (7) aufweist, zum Erkennen, insbesondere zum Messen, einer Potential differenz zwischen dem Sternpunkt (6) und dem Neutralleiter (N).