Abstract: A switchgear comprises a switching device, such as a relay, with a switching mechanism. A printed-circuit board that is provided with at least one electronic component is electrically connected to the switching device to form a supplementary electrical circuit, which receives an operating voltage supplied to the switching device.

Abstract: Disclosed herein is an apparatus for detecting an arc fault, which prevents a malfunction caused by a conventional current detecting method by detecting a source voltage applied onto a conductive wire to determine whether there is an arc fault, prevents a malfunction with respect to a pseudo arc signal by dividing a current detecting route into two according to the magnitude of a load current occurring onto the conductive wire to determine whether there is the arc fault by voltage detection, and lessens the danger of a fire by reducing a circuit break time according to the magnitude of the load current. A voltage detector detects the arc fault by use of two detecting routes. Each route differs in a filtering value of a filter, presence/absence of level limit, an amplification factor of an amplifier, an accumulation value of a comparator, etc. according to the magnitude of a load current occurring on a conductive wire, thereby reducing a circuit break time.

Abstract: An arc fault circuit interrupter includes separable contacts, an operating mechanism adapted 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 peak detector determining a peak amplitude of a current pulse of the current flowing in a power circuit. A microprocessor determines whether the peak amplitude of the current pulse is greater than a predetermined magnitude. A plurality of routines including a time discounted accumulation algorithm, a short delay algorithm and a series time discounted accumulation algorithm, employ the peak amplitude to determine whether an arc fault condition exists in the power circuit.

Abstract: A contactor having a separable conduction path, an actuator, a magnetic stator and armature, and a controller, is disclosed. The actuator is in mechanical communication with the separable conduction path, and the magnetic stator and magnetic armature are arranged in field communication with each other and with an excitation coil responsive to a coil current that serves to generate a magnetic field directed to traverse the stator and the armature. The controller has a processing circuit adapted to control the coil current in response to the current and voltage at the coil such that the coil current is controlled in response to the position and closing speed of the separable conduction path prior to the separable conduction path closing during an open-to-close action.

Abstract: A method of eliminating arc flash in a motor control center is disclosed. The method includes sensing an arc flash corresponding to the motor control center. In response to sensing the arc flash, and subsequent to a delay, determining whether the arc flash continues, and in response to determining that the arc flash continues, triggering an arc crowbar.

Abstract: Arc suppression systems, devices and methods for avoiding undesirable arcing conditions inside a liquid-filled tank of a high-voltage electrical apparatus.

Abstract: There is here disclosed a method and apparatus for detecting the occurrence of arcing of a conductor by monitoring the current on an AC power line. The signal detected is split and directed along four separate paths to generate four signals having separate characteristics which represent the current in the line. A first path is for a signal representative of the current flowing in the line. A second path is for a signal having a pulse for each occurrence of a positive step change in current that is significant and has a di/dt value above a predetermined value. A third path is for a signal having a pulse for each occurrence of a negative step change in current that is significant and has a di/dt value above a predetermined value. A fourth path is for a signal having a voltage level representative of the broadband noise signal on the line. Using at least one of five different methods in combination with one of three input signals, a reference signal designated as “SINE” is generated.

Abstract: A control arrangement is operable to control an electrical relay to supply current. The arrangement comprises current supply means and control means operable to provide a relay make signal and a relay break signal to control the state of the relay to respectively make and break a connection to the current supply means. Further control means are operable to enable or disable the current supply means. A first delay means operates to delay enabling the current supply means until after a relay make signal has been provided, to allow the relay to make the connection before current supply commences. Excess current is also sensed and controlled by a form of pulse-width modulation.

Abstract: A non-invasive underground arc fault detection apparatus is for an underground electrical conductor. The apparatus includes an electric circuit having an opening for admitting the electrical conductor therethrough. The electric circuit includes one or two transducers adapted to output a first signal representative of current flowing in the electrical conductor and a second signal. An arc fault detection circuit cooperates with the electric circuit to output a third signal derived from the first signal. The third signal is representative of an arc fault of the electrical conductor. An audible annunciator cooperates with the arc fault detection circuit to annunciate the third signal. A power supply cooperates with the electric circuit and is adapted to power the arc fault detection circuit and the annunciator from the second signal.

Abstract: Certain exemplary embodiments described herein comprise a method comprising a plurality of activities comprising: discriminating an arcing condition from a non-arcing broadband signal, and, in response to detecting an arcing condition, outputting a trip signal to a circuit breaker controlling a predetermined alternating current circuit associated with the arcing condition.

Abstract: A method and occupancy-based control device in a trip unit of a main circuit breaker, with the circuit breaker coupled to an electrical distribution system including at least one feeder circuit breaker and a load circuit. The occupancy-based control device comprises an input device associated with the electrical distribution system and coupled to the trip unit. A selector is coupled to the trip unit and configured to select a first set of parameters and a second set of parameters, with each set of parameters defining a mode of operation of the trip unit. A means for selecting one of the first set of parameters and a second set of parameters in response to a signal from the input device is provided wherein, the trip unit operates based on the selected set of parameters.

Abstract: An arc fault detection circuit collects samples of sensed current, determines a peak current value from the samples for each line cycle, determines a hysteresis value for a compressor load as a function of differences between the peak current values, and generates a trip signal responsive to the sensed current and the hysteresis value. The circuit determines a difference value for each line cycle from the present peak current value less the previous peak current value, low pass filters the difference value to provide a low pass filtered value, determines a peak value from the low pass filtered value, determines that the absolute value of the low pass filtered value is less than a portion of the peak value and responsively saves the peak value, and determines the hysteresis value as a function of the saved peak value. An operating mechanism opens separable contacts responsive to the trip signal.

Abstract: An encapsulated medium voltage vacuum circuit interrupter includes a line terminal, a load terminal, a vacuum interrupter, an operating mechanism and an elongated, insulated, generally cylindrical encapsulating housing. The vacuum interrupter includes a vacuum envelope containing a fixed contact assembly and a movable contact assembly movable between a closed circuit position in electrical communication with the fixed contact assembly and an open circuit position spaced apart from the fixed contact assembly. The fixed contact assembly is electrically interconnected with the line terminal. A flexible conductor electrically connects the movable contact assembly with the load terminal. The operating mechanism moves the movable contact assembly between the closed circuit position and the open circuit position. The housing includes a first end supporting the line terminal and an opposite second end supporting the load terminal.

Abstract: Maintenance trip functions override the normal or specified trip functions of a low voltage circuit breaker to reduce pickup currents and/or time delays to effect faster trips, which reduces arc energy produced by faults during maintenance or testing on a live circuit breaker.

Abstract: An apparatus and method for detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping (firing) circuit, a processor, and an electromechanical interface. The current sensor monitors a power input comprising an AC current, and provides high frequency components of the. AC current to the input sense circuit. The input sense circuit filters and rectifies the AC signal, and provides the rectified signal to the arcing sense circuit. The arcing sense circuit provides a voltage level accumulated over a predetermined time period, and digital signals indicative of possible electrical arcing occurring during the sampling period, to the processor.

Abstract: An apparatus and method for detecting arc faults that have reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping (firing) circuit, a processor, and an electromechanical interface. The current sensor monitors a power input comprising an AC current, and provides high frequency components of the. AC current to the input sense circuit. The input sense circuit filters and rectifies the AC signal, and provides the rectified signal to the arcing sense circuit. The arcing sense circuit provides a voltage level accumulated over a predetermined time period, and digital signals indicative of possible electrical arcing occurring during the sampling period, to the processor.

Abstract: An apparatus includes a first circuit detecting when an absolute value of a current signal is less than a first predetermined value and outputting a signal after a first time period. A comparator compares that signal to an envelope of a rectified current signal, in order to provide an output with a plurality of pulses that persist for a relatively longer time for a relatively small value of the envelope, and persist for a relatively shorter time for a relatively large value of the envelope. A second circuit enables the comparator output if the rectified current signal exceeds a second predetermined value, and disables the comparator output after the rectified current signal is below the second predetermined value for a second time period. A third circuit accumulates the pulses and outputs a signal representative of a wet track arc fault.

Abstract: A switching device includes at least one MOSFET switching element and at least one JFET protective element, which is connected electrically in series to the switching element and which limits the electric current to a maximum current (saturated current) and control elements, which increase the maximum current of the JFET protective element during the closing operation or in a time-delayed manner, at least in the temporal mean, to at least a higher value and subsequently reduce said maximum current to at least a lower value. The advantage of said switching device is that it allows higher starting or closing overcurrents, which are subsequently limited.

Abstract: It is so arranged in a robot as to monitor the over-current state of each motor and that of two more than two motors when put together by seeing the total current value of the motors being monitored in parallel with absorption of both the static load torque and the dynamic load torque of each actuator/motor. Additionally, it is so arranged as to check if each of the predetermined unit members including the arm sections and the leg sections of the robot is in an over-current state or not and also if the entire robot is in an over-current state or not, while each of the motors are not in an over-current state.

Abstract: There is here disclosed a method and apparatus for detecting the occurrence of arcing of a conductor by monitoring the current on an AC power line. The signal detected is split and directed along four separate paths to generate four signals having separate characteristics which represent the current in the line. A first path is for a signal representative of the current flowing in the line. A second path is for a signal having a pulse for each occurrence of a positive step change in current that is significant and has a di/dt value above a predetermined value. A third path is for a signal having a pulse for each occurrence of a negative step change in current that is significant and has a di/dt value above a predetermined value. A fourth path is for a signal having a voltage level representative of the broadband noise signal on the line. Using at least one of five different methods in combination with one of three input signals, a reference signal designated as “SINE” is generated.

Abstract: An arc fault circuit interrupter which protects an AC circuit subjected to a possible arcing fault includes a sensor which produces a signal that can be evaluated to see if it is associated with arc fault current. The evaluation is done by a discrimination circuit which identifies a characteristic of the sensor signal associated with cessations of the arc fault current. An accumulator counts the number of occurrences of the cessations, and if the number of cessations counted within a predetermined time interval exceeds a predetermined number, the arc fault circuit interrupter interrupts the AC circuit.

Abstract: The forming of an integrated circuit including at least one element of electronic protection of the circuit formed of at least one switch for short-circuiting supply conductors arranged in a rail, the switch being integrated in the rail, under said conductors.

Abstract: An electronically controlled circuit breaker for detecting arc and a method for detecting arc conditions are disclosed. The circuit breaker and method uses digital Fourier transformation on sampled line current signals and bins the even, odd, and fundamental transforms. Even arc signals and non-harmonic arc signals are calculated from the values in the bins and used within an expert arc algorithm which uses an accumulator to sum an increment based on whether the even arc signals and non harmonic arc signals exceed a fixed threshold. A trip signal is issued when the increment exceeds a predetermined value.

Abstract: A method for controlling the closing operation of a switching device, which is disposed on an electrical network connected to an inductive component. The method requires first data related to the electrical characteristics of the inductive component and the electrical network. Based on the first data, on a predefined first storage device containing opening and closing operation sequences, a first predefined opening operation sequence is selected. Then, based on the first predefined opening operation sequence, on the first storage device, a first predefined closing operation sequence is selected.

Abstract: The invention discloses an arc extinguishing aid with an externally powered magnetic blowout coil 3 for switching low currents in which the current direction in the externally powered magnetic blowout coil 3 is switched based on the detection of the current direction in the primary circuit of a DC power switch.

Abstract: Adaptively controlled circuits are provided that can include an output buffer circuit, a sensing circuit, and a current conversion circuit. The output buffer circuit can include, for example, inputs, outputs and a bias control input. The sensing circuit can also include inputs and outputs. Two or more sensing circuit outputs can simultaneously turn to lower or higher level than a predetermined threshold level. The current conversion circuit can be composed of one or more set of cascaded transistors. Inputs of the cascaded transistors can be connected to outputs of the sensing circuit. The output of the cascaded transistors can be connected to foresaid bias control input of the output buffer. An output current of the current conversion circuit increases when signal level of the inputs of the sensing circuit become equal or close to each other.

Abstract: An arc fault circuit interrupter which protects an AC circuit subjected to a possible arcing fault includes a sensor which produces a signal that can be evaluated to see if it is associated with arc fault current. The evaluation is done by a discrimination circuit which identifies a characteristic of the sensor signal associated with cessations of the arc fault current. An accumulator counts the number of occurrences of the cessations, and if the number of cessations counted within a predetermined time interval exceeds a predetermined number, the arc fault circuit interrupter interrupts the AC circuit.

Abstract: A method of determining whether arcing is present in an electrical circuit includes sensing a change in current in the circuit and developing a corresponding input signal, analyzing the input signal to determine the presence of broadband noise in a predetermined range of frequencies, and producing a corresponding output signal, and processing the input signal and the output signal in a predetermined fashion to determine whether an arcing fault is present in the circuit. The processing includes determining a type of load connected to the electrical circuit, based at least in part upon the input signal and the output signal.

Abstract: To provide a method of synchronous circuit opening of generator circuit breaker and its control apparatus that can protect a sound generator system of a generator main circuit from a phenomenon that current may not pass through current zero for many cycles. There is provided a construction where a generator exciting current control is incorporated into a control mechanism. In case that an occurrence possibility of a phenomenon that current may not pass through current zero for many cycles can be anticipated, time delay is intentionally caused by timer so as to prevent synchronism of the phenomenon, using an output signal of a generator lock-out relay which covers individual element of an electrical fault causing the phenomenon or in which circuit all those elements are integrated. In case that the phenomenon can be anticipated by calculation, a reactive power output of a generator is increased and consequently AC current amplitude of a sound generator is increased so as to eliminate the phenomenon.

Abstract: A method for interrupting current is provided wherein substantially all current is conveyed through a normal current carrying path in a circuit interrupter. A movable element is displaced for interruption of the current, and a balance is struck between the normal current carrying path and a parallel alternative or transient current carrying path. The transient current carrying path includes at least one variable or controllable resistance element. The transient current carrying path presents a substantially open circuit during normal operation. The variable resistance elements have a lower resistance during initial phases of circuit interruption, favoring transition of all current from the normal current carrying path to the transient path. Thereafter, the variable resistance elements increase in resistivity, producing additional back-EMF to drive the fault current to a zero level and to limit let-through energy.

Abstract: A switch gear protection circuit for use in electric vehicles provides parallel circuit pathways for selectively coupling a power source to a capacitive load. A first pathway includes a main switch element that preferably is a high-current contactor or a high-current, low-voltage relay switch. A second pathway, which is in parallel with the first pathway, includes a low-voltage, low-current switch element in series with a circuit breaker element such as a fuse. When it is desirable to open the main switch element in the first pathway, the second pathway is closed. Once the second pathway is closed, the voltage drop across the first pathway is reduced and the first switch element can be opened. The parallel arrangement provides the ability to use low-voltage switch elements, that are relatively inexpensive compared to high-voltage components.

Abstract: An arcing fault protection system for a switchgear enclosure includes a switching device for rapidly diverting current from the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The switching device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at high pressures and/or temperatures so as to protect the switchgear equipment from damage.

Abstract: The present invention includes a first switch 4a, a second switch 4b and a capacitor 4d. The first switch 4a normally in a closed state is connected in series between a power source 1 and load, and opens when an accident builds up. The second switch 4b normally in an open state closes almost simultaneously with the opening of the first switch 4a. The capacity 4d normally charged by an arbitrary voltage has predetermined electrically capacity. The serial connected circuit consists of the second switch 4b and capacitor 4d, it is connected in parallel to the first switch 4a.

Abstract: A power operator for switchgear and the like is provided that is capable of either power or manual operation without the necessity of any decoupling or mode selection. The power operator is compact and easily affixed over a manual operating shaft of switchgear. The manual drive capabilities are always coupled for operation without any backdriving of the power source. The power operator includes a drive output affixed to the switchgear operating shaft, a manual operating shaft, and an arrangement for selectively coupling a power-driven input to the switchgear operating shaft. In a specific arrangement, the control arrangement of the power operator senses the position of the drive output and also senses the current drawn by the drive source. When controlling switchgear having a stored energy mechanism, operating positions are detected by sensing the tripping of the stored energy mechanism via the sensed current through the drive source.

Abstract: A circuit for the protected alternating current power supply of an electrical load, the circuit including, in series, a protective circuit breaker and a bi-directional electronic switch in parallel to which a shunt contactor is connected. An electrical component is connected in series and upstream from the shunt contactor. The electrical component is intended to establish a continuous voltage (V) at the terminals of the electronic switch and its impedance is chosen in such a way that the electronic switch to which command pulses are sent periodically, is made a conductor, when an overload current appears in the circuit and when the contactor is closed.

Abstract: An arcing fault protection system for a switchgear enclosure includes a grounding device for rapidly grounding the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The grounding device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to ground to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at hazardous pressures and/or temperatures so as to protect the switchgear equipment from damage and to prevent injury to operating personnel.

Abstract: A power operator for switchgear and the like is provided that is capable of either power or manual operation without the necessity of any decoupling or mode selection. The power operator is compact and easily affixed over a manual operating shaft of switchgear. The manual drive capabilities are always coupled for operation without any backdriving of the power source. The power operator includes a drive output affixed to the switchgear operating shaft, a manual operating shaft, and an arrangement for selectively coupling a power-driven input to the switchgear operating shaft. In a specific arrangement, the control arrangement of the power operator senses the position of the drive output and also senses the current drawn by the drive source. When controlling switchgear having a stored energy mechanism, operating positions are detected by sensing the tripping of the stored energy mechanism via the sensed current through the drive source.

Abstract: A switching device including a measuring means for monitoring contact erosion, which is provided between a contact element and an associated contact support. The switching device includes an electrically insulated signal line, which is usable in individual and/or multiple contacts, is used as the measuring means, the signal line being integrated into a single monitoring circuit. In the switching device, there is arranged, between at least one of the contact elements and the associated contact support or in the contact material, an electrical conductor with insulator as the signal line, damage to or destruction of the insulator and/or the conductor being utilized to generate an external signal as an indication of the end of the service life of the contact element.

Abstract: A junction box architecture includes a main circuit breaker, plurality of branch circuit breakers, and an arc detection unit. The main circuit breaker input is connected to main power supply lines, e.g., phase 1 and phase 2 power lines. The main circuit breaker output is connected to respective inputs of branch circuit breakers and to an input of the arc detection unit. The arc detection unit includes an enable output and is configured to generate an enable signal on the enable output. The enable output is coupled to enable inputs of each branch circuit breaker. When no enable signal is present on an enable input of any one branch circuit breaker, the one breaker will not trip. In general, for any one circuit breaker to trip, the breaker must simultaneously detect a high frequency current in the associated branch circuit and receive an enable signal from the arc detection unit.

Abstract: A plurality of solid-state switches are provided in parallel with a main circuit switch. A main circuit current is detected by a first current detecting device. A current flowing in each of the plurality of solid-state switches is detected by a second current detecting device. Based on the detected currents of the first and second current detecting devices, the main circuit switch is commanded to open and each solid-state switch is commanded to close by a control circuit, when a fault is detected by a fault detecting circuit. At this point of the process when the main circuit switch is opened, when a commutation anomaly is detected by a commutation detecting circuit, the conducting status of each solid-state switch is maintained. When the commutation achieves a normal status, each solid-state switch is interrupted and circuit breaking, at the point the capability of each solid-state switch is exceeded, is prevented.

Abstract: Substation for the distribution of electrical energy, and protected against arcing faults, characterized by the fact that Hall-effect sensors and additional optical fiber conductors are provided as sensors, whereby the Hall-effect sensors are logically AND linked with the optical fiber conductors.

Abstract: The first zero crossing of the power signal, after the detection of an opening/closing signal, initiates a series of predetermined, timed, steps which reduces or eliminates the overvoltage after opening/closing a circuit breaker on a high power line.

Abstract: A plasma switch is provided which can limit fault currents to a range that is elecrostatically interruptible by a control grid. The switch includes magnets that generate a first magnetic vector which cooperates with an electric field to generate a plasma, the density of which is a function of the magnitude of the first magnetic vector. A stalling coil is arranged to generate a second magnetic vector that opposes and cancels a portion of the first magnetic vector in response to a fault current through the switch. This establishes a stalling condition in which the plasma density falls and a plasma potential gradient is set up in the switch. In this unstable condition, the plasma current is interruptible by the control grid.

Abstract: A system and method for protecting relay contacts from erosion utilizes a sensor which senses voltage change in a switch controlling a load relay. In response to operation of the switch, the sensor sends a current to a set of pass transistors which are connected in series to the load power source and the load to turn off the transistors thereby cutting off load current flow to the load. A delay element is connected in series between the sensor and the set of transistors which cuts off the current flow to the set of transistors for a period of time selected to enable the load relay contacts to fully close or fully open before conducting electrical current therethrough.

Abstract: A control circuit synchronizes operation of a latching relay to extend contact life. The relay is switched using an H-bridge drive circuit. The synchronization is done using a two-step delay. The first delay is provided by a phase shifter, which delays the timing signals used by a logic controller relative to a zero crossing. The second delay is provided by an adjustable timer circuit including a potentiometer. The two delays are used so that the latching relay is tripped at a selectable time coinciding with the second zero crossing after a switching command is received.

Abstract: An Ethernet adapter card for automatically switching a workstation into a network is provided. The adapter card utilizes a current circuit to sense current drawn by an external communications network and a circuit for automatically switching between a card-mounted internal transceiver and the network's external transceiver whenever the external network is coupled to the workstation via an AUI port. The adapter card provides for default selection of the internal transceiver when the external communication network is disconnected from the workstation AUI port.

Abstract: A remotely controllable circuit breaker and switch for controlling the flow of current from a three phase AC power source to a three phase load, and usable in either wye or delta configurations. A latching relay controls the current for each phase. Current samples in the three phases are scaled and converted to DC values by scalers and RMS to DC converters. The DC values are converted to digital current values by an analog-to-digital converter which sequentially scans the DC values of the currents in the three phases. A central processing unit monitors the digital current values to detect significant phase imbalances and overcurrents which persist for time periods which exceed allowable limits according to a predetermined time-dependent function, and to initiate opening of the relays in response thereto. The central processing unit also opens and/or resets the relays in response to remote control signals.

Abstract: When the runner of a linear motor having a long stator which is divided into sections crosses from a first section to a second section, an inverter power supply, which was providing current to the first section via a first switching unit having a relay, is initially gated out. Then the main relay contact paths in the first switching unit are opened and main relay contact paths in a second switching unit for the second section are closed. Only then is the power supply gated in again.

Abstract: A method for operating a circuit-breaker by means of which one is able by using a vacuum circuit-breaker, to interrupt inductive circuits without causing disturbing overvoltages. The switching operation of the vacuum circuit-breaker is influenced by a tripping control device, which is supplied with a measured value of the tripping delay of the vacuum circuit-breaker from the instant the tripping signal is output to the instant the contact members are separated as a correcting quantity, in the case of an opening operation that occurred previously. The temperature of the actuator unit of the vacuum circuit-breaker, the standstill time of the circuit-breaker, as well as the operating voltage and temperature of a tripping solenoid can be used as further correcting quantities. The described method is suited for application vacuum circuit-breakers in circuits with inductive components.

Abstract: A contactor (12) for controlling connection of a DC power supply to an electrical load (14) in includes a series circuit (19) disposed between a nonground DC potential and a load having first (20) and second (22) relays each having a pair of contacts (26), the first relay and the second relay having a conducting state when the pair of contacts are closed and a non-conducting state when the pair of contacts are open which control current flow between the DC power supply and the load with the states being controlled by control signals applied to the relays; a semiconductor switch (24) having a conductive state controlled by a control signal to turn on the semiconductor switch to connect the semiconductor switch in parallel with the contacts of the first relay and a non-conductive state controlled by a control signal to turn off the semiconductor switch to disconnect the terminals of the semiconductor switch; a fault sensor (50) coupled to the load for generating a signal in response to the load drawing current