Abstract:
A method of protecting a power distribution system from a fault on a feed conductor thereof, wherein an HFAC signal is provided to the feed conductor from a location downstream of the feed conductor in the power distribution system. The method includes, in a module located upstream of the feed conductor in the power distribution system, determining an HFAC signal magnitude in the module, the module including a circuit interrupter, and controlling operation of the circuit interrupter based on the determined magnitude.
Abstract:
A current sensing assembly includes a conductor, first and second magnetic sensors disposed proximate to opposite sides of the conductor and being structured to output first and second voltage signals, a current direction detector circuit structured to detect a direction of a current flowing through the conductor, a switching circuit having first and second outputs and being structured to switch between a first condition where the first voltage signal is output to the first output and the second voltage signal is output to the second output and a second condition where the first voltage signal is output to the second output and the second voltage signal is output to the first output based on the switching signal, and an output circuit including a differential amplifier structured to amplify a voltage difference between the first and second voltage signals and to output the amplified voltage difference.
Abstract:
Circuit breakers include an arc chamber and an arc chute comprising a plurality of arc plates in the arc chamber. The circuit breakers also include a line conductor assembly with at least one arc runner attached to a line conductor in the arc chamber. The arc runner can extend below but adjacent to a bottom arc plate to thereby guide a respective arc into the arc chute.
Abstract:
An electrical switching apparatus includes a transductor circuit that senses a direct current between at least one input terminal and at least one output terminal and outputs an alternating current proportional to the direct current between the input terminal and the output terminal. The electrical switching apparatus also includes an alternating current electronic trip circuit configured to control pairs of separable contacts to separate based on the alternating current output from the transductor circuit. The alternating current electronic trip circuit includes a rectifier circuit, an interface circuit, and a processor structured to output a control signal to control a trip actuator to cause an operating mechanism to separate the plurality of pairs of separable contacts.
Abstract:
A system and method for detecting excess voltage drop (EVD) in a three-phase electrical distribution circuit includes a diagnostic system comprising a processor that is programmed to receive three-phase voltages and currents provided to terminals of the electrical machine, determine fundamental components of the three-phase voltages and currents provided to the terminals, and compute positive, negative, and zero sequence currents from the fundamental components. The processor is also programmed to extract a compensated negative sequence current from the negative sequence current component, add the compensated negative sequence current to the positive sequence current to determine fault reference current phasors, determine a negative current reference phase angle for each phase based in part on a phase angle of the positive sequence current, and identify an EVD fault in the electrical distribution circuit based on the compensated negative sequence current, the fault reference current phasors, and the negative current reference phase angles.
Abstract:
A circuit breaker apparatus may include a housing, a circuit inside the housing for protecting the conductors and the load of the circuit, a display attached to outside of the housing, a controller, and a power control device. The display may be an electronically-alterable display that does not require power in situations other than changing its state. The power control device may provide power to the controller and the display when the apparatus is being tampered with. When the controller is powered, it may cause the power control device to cause the display to change from a state that indicates that the apparatus is authenticated to another state that indicates that the apparatus has been tampered with. The power control device may include a battery and a switch, or a power harvester, which can be configured to provide power to the controller when the apparatus is being tampered with.
Abstract:
A hybrid switch assembly for a circuit breaker assembly is provided. The circuit breaker assembly includes a housing assembly and an operating mechanism. The housing assembly defines a power electronic switch assembly cavity. A hybrid switch assembly includes a number of conductor assemblies, each conductor assembly including a movable conductor, and a stationary conductor. Further, each movable conductor is structured to move between an open, first position, wherein each movable conductor is spaced from and not in electrical communication with an associated stationary conductor, and a closed, second position, wherein each movable conductor is coupled to and in electrical communication with an associated stationary conductor. A number of the conductor assemblies further include a power electronic switch assembly. Each power electronic switch assembly includes an isolation contact assembly. Each isolation contact assembly is selectively coupled to, and in electronic communication with, the stationary conductor and the movable conductor.
Abstract:
An electrical switching apparatus includes a transductor circuit that senses a direct current between at least one input terminal and at least one output terminal and outputs an alternating current proportional to the direct current between the input terminal and the output terminal. The electrical switching apparatus also includes a current sensor configured to sense an alternating current component of the direct current. The electrical switching apparatus further includes an alternating current electronic trip circuit including an arc fault detection circuit configured to detect an arc fault based on the sensed alternating current component. The alternating current electronic trip circuit is also configured to control pairs of separable contacts to trip open based on the alternating current output from the transductor circuit or the detected arc fault.
Abstract:
A circuit breaker including a pair of separable contacts and an arc chamber is provided. The separable contacts include a fixed contact having an upper surface. The arc chamber includes magnetic members disposed on either side of the separable contacts. The magnetic members have a lower surface below the fixed contact upper surface.
Abstract:
A system and method for detecting excess voltage drop (EVD) in a three-phase electrical distribution circuit includes a diagnostic system comprising a processor that is programmed to receive three-phase voltages and currents provided to terminals of the electrical machine, determine fundamental components of the three-phase voltages and currents provided to the terminals, and compute positive, negative, and zero sequence currents from the fundamental components. The processor is also programmed to extract a compensated negative sequence current from the negative sequence current component, add the compensated negative sequence current to the positive sequence current to determine fault reference current phasors, determine a negative current reference phase angle for each phase based in part on a phase angle of the positive sequence current, and identify an EVD fault in the electrical distribution circuit based on the compensated negative sequence current, the fault reference current phasors, and the negative current reference phase angles.