A circuit breaker includes a solid-state switch, a sense resistor, a current detection circuit, and a switch control circuit. The solid-state switch and sense resistor are connected in series in an electrical path between a line input terminal and a load output terminal of the circuit breaker. The current detection circuit is configured to (i) sample a sense voltage that is generated across the sense resistor in response to load current flowing through the sense resistor, (ii) detect an over-current fault condition based on the sampled sense voltage, and (iii) output a fault detection signal in response to detecting the over-current fault condition. The switch control circuit is configured to control the solid-state switch, wherein the switch control circuit is configured to switch off the solid-state switch in response to the fault detection signal output from the current detection circuit.

A contactor apparatus and method for operating the contactor apparatus can include a contactor assembly with a contactor coil operably coupled to a contactor switch. One or more sensors can be provided in the contactor assembly adapted to measure one or more aspects of the contactor assembly. Based upon the measured aspects, a controller can initiate operation of the contactor switch to effectively toggle the contactor switch at a zero-crossing point along an alternating current waveform.

A high speed arc suppressor and method include a first phase-specific arc suppressor configured to suppress arcing across contacts of the power contactor in a positive domain and a second phase-specific arc suppressor configured to suppress arcing across the contacts in a negative domain. First and second high speed switches are configured to enable and disable operation of an associated one of the first and second phase-specific arc suppressors. First and second drivers are configured to drive the first and second high speed switches.

An arc suppressing circuit configured to suppress arcing across a power contactor coupled to an alternating current (AC) power source having a predetermined number of phases, each contact of the power contactor corresponding to one of the predetermined number of phases includes a number of dual unidirectional arc suppressors equal to the predetermined number of phases of the AC power source. Each dual unidirectional arc suppressor includes a first phase-specific arc suppressor configured to suppress arcing across the associated contacts in a positive domain, a a second phase-specific arc suppressor configured to suppress arcing across the associated contacts in a negative domain, and a coil lock controller, configured to be coupled between a contact coil driver of the power contactor, configured to detect an output condition from the contact coil driver and inhibit operation of the first and second phase-specific arc suppressors over a predetermined time.

An arc suppressing circuit configured to suppress arcing across a power contactor coupled to an alternating current (AC) power source having a predetermined number of phases, each contact of the power contactor corresponding to one of the predetermined number of phases includes a number of dual unidirectional arc suppressors equal to the predetermined number of phases of the AC power source. Each dual unidirectional arc suppressor includes a first phase-specific arc suppressor configured to suppress arcing across the associated contacts in a positive domain, a a second phase-specific arc suppressor configured to suppress arcing across the associated contacts in a negative domain, and a coil lock controller, configured to be coupled between a contact coil driver of the power contactor, configured to detect an output condition from the contact coil driver and inhibit operation of the first and second phase-specific arc suppressors over a predetermined time.

A circuit breaker comprises a solid-state bidirectional switch, a switch control circuit, current and voltage sensors, and a processor. The solid-state bidirectional switch is connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-on state and a switched-off state. The switch control circuit control operation of the bidirectional switch. The current sensor is configured to sense a magnitude of current flowing in an electrical path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage on the electrical path and generate a voltage sense signal. The processor is configured to process the current and voltage sense signals to determine operational status information of the circuit breaker, a fault event, and power usage information of a load connected to the load output terminal.

A high speed arc suppressor and method include a first phase-specific arc suppressor configured to suppress arcing across contacts of the power contactor in a positive domain and a second phase-specific arc suppressor configured to suppress arcing across the contacts in a negative domain. First and second high speed switches are configured to enable and disable operation of an associated one of the first and second phase-specific arc suppressors. First and second drivers are configured to drive the first and second high speed switches.

The invention relates to monitoring operation of a switching device in a power system, where a load is connected to a power source through the switching device. The load has windings, with coupling between at least one of two or more phases of a winding, and two or more windings of the load. The method includes obtaining measurements of at least one of voltages and currents, at one or more of a source and load side. Further, the method determines an electrical parameter associated with electrical switching of one or more poles. The parameter for each pole is determined based on at least one of voltage measurements at the source and load side, and line measurements associated with at least one winding. The values of the electrical parameter are monitored to determine the switching instant of the pole, for determining mechanical operating time deviation for estimating future switching instants.

A circuit breaker includes an electromechanical switch, a current sensor, a voltage sensor, and a processor. The electromechanical switch is serially connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-closed state or a switched-open state. The current sensor is configured to sense a magnitude of current flowing in a path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage at a point on the path between the line input and load output terminals and generate a voltage sense signal. The processor is configured to receive and process the current sense signal and the voltage sense signal to determine operational status information of the circuit breaker and determine power usage information of a load connected to the load output terminal.

A circuit breaker includes an electromechanical switch, a current sensor, a voltage sensor, and a processor. The electromechanical switch is serially connected between a line input terminal and a load output terminal of the circuit breaker, and configured to be placed in a switched-closed state or a switched-open state. The current sensor is configured to sense a magnitude of current flowing in a path between the line input and load output terminals and generate a current sense signal. The voltage sensor is configured to sense a magnitude of voltage at a point on the path between the line input and load output terminals and generate a voltage sense signal. The processor is configured to receive and process the current sense signal and the voltage sense signal to determine operational status information of the circuit breaker and determine power usage information of a load connected to the load output terminal.