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 method of detecting and locating a micro-interface abnormality within an electrical system having a plurality of conductors and a plurality of electrical connections includes identifying a subset of the plurality of electrical connections by detecting an acoustic signal within the electrical system and analyzing the detected acoustic signal and determining that the detected acoustic signal is indicative of an electrical fault, measuring a contact resistance of each of the subset of the plurality of electrical connections, and identifying at least one of the subset of the plurality of electrical connection points as having a micro-interface abnormality based on the measured contact resistances.
Abstract:
An electrical switching apparatus includes two arc runners, two contacts in electrical communication with the respective runners, a movable contact having two portions respectively cooperating with the contacts to provide closed and open contact positions, and two arc chambers each including two ends, a longitudinal axis therebetween, and arc plates between the ends. A magnet assembly cooperates with the arc chambers to establish a generally unidirectional magnetic field normal to the axes, normal to a first direction of a first arc between one contact and the first portion as it moves away from the closed toward the open contact position, and normal to an opposite second direction of a second arc between the other contact and the second portion as it moves away from the closed toward the open contact position. The magnetic field causes one arc to enter one arc chamber depending upon current flow direction between the contacts.
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:
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 an input terminal and an output terminal and outputs an alternating current proportional to the direct current. 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. The electrical switching apparatus also includes a power supply structured to provide direct current power to the alternating current electronic trip circuit.
Abstract:
A thermal trip assembly for use with a busbar includes a fastener, an insulating sleeve, a temperature sensor structured to sense a temperature of the busbar, and a thermal trip circuit structured to output a trip signal based on the sensed temperature. A portion of the insulating sleeve is disposed between the temperature sensor and the busbar. The fastener couples the insulating sleeve and the temperature sensor to the busbar with the insulating sleeve being in direct contact with a portion of the busbar.
Abstract:
An electrical switching apparatus for bi-directional direct current switching and interruption includes separable contacts, an operating mechanism to open and close the contacts, and an arc chute. The arc chute includes two ferromagnetic side members each having a first side and an opposite second side, the first side of a second ferromagnetic side member facing the first side of a first ferromagnetic side member, a first permanent magnet disposed on the first side of the first side member, a second permanent magnet disposed on the first side of the second side member, and a single set of a plurality of arc splitter plates disposed between the permanent magnets. The permanent magnets are substantially smaller in size than each of the side members. The arc chute is divided into two arc chambers each of which is for a corresponding direction of DC flow through the contacts.
Abstract:
A system and method for detecting and localizing excess voltage drop in single or multiple phases of three-phase AC circuits is disclosed. An electrical distribution circuit is provided that includes an input connectable to an AC source, an output connectable to terminals of an electrical machine, the output configured to provide three-phase voltages and currents to the electrical machine, and a diagnostic system configured to detect an excess voltage drop (EVD) in the electrical distribution circuit. The diagnostic system includes a processor that is programmed to receive measurements of the three-phase voltages and currents provided to the electrical machine, compute a negative sequence voltage from the three-phase voltages and currents, determine a localization reference phase angle for each phase based in part on the three-phase voltages and currents, and calculate an EVD in the electrical distribution circuit based on the negative sequence voltage and the localization reference phase angles.
Abstract:
A circuit for sensing a direct current includes a first resistance and a second resistance. A first portion of the direct current flows through the first resistance and a second portion of the direct current flows through the second resistance. The circuit further includes a current sensor having an opening, first and second conductors inductively coupled with the current sensor, and a switching circuit having a pair of switches structured to alternatingly switch in order that the second portion of the direct current alternatingly flows through the first and second conductors. The second portion of the direct current flowing through the first conductor passes through the opening of the current sensor in a first direction and the second portion of the direct current flowing through the second conductor passes through the opening of the current sensor in a second direction opposite to the first direction.