A device includes an electro-mechanical switching device having an open-circuit and closed-circuit conditions and a path of least resistance having a path input and a path output with the switching device between the input and the output. The device includes a bypass power switch device that comprises a solid-state circuit interrupter and that is configured to conduct current between the input and the output in response to an open-circuit condition of the switching device. The device includes a current sensor that is connected to the output and configured to detect a fault current event. The device includes an actuator that is coupled to the switching device and a controller that is configured to generate a trigger signal to activate the actuator to cause the open-circuit condition of the switching device and to interrupt the fault current event by the power switch device, based on the detected fault current event.

A method of determining if a circuit interrupter operating mechanism has an acceptable trip margin includes determining a model trip margin, providing a circuit interrupter, the circuit interrupter disposed in situ, the circuit interrupter including an operating mechanism, determining a circuit interrupter trip margin by: providing an internal sensor assembly, the internal trip margin sensor assembly structured to record trip margin data, providing a transfer function module, providing a computer structured to execute the transfer function module, executing the transfer function module on the computer, utilizing the trip margin sensor assembly to generate trip margin data, transmitting the trip margin data to the transfer function module, processing the trip margin data to generate a trip margin, and determining if the trip margin is acceptable relative to the model trip margin.

A method of determining if a circuit interrupter operating mechanism has an acceptable trip margin includes determining a model trip margin, providing a circuit interrupter, the circuit interrupter disposed in situ, the circuit interrupter including an operating mechanism, determining a circuit interrupter trip margin by: providing an internal sensor assembly, the internal trip margin sensor assembly structured to record trip margin data, providing a transfer function module, providing a computer structured to execute the transfer function module, executing the transfer function module on the computer, utilizing the trip margin sensor assembly to generate trip margin data, transmitting the trip margin data to the transfer function module, processing the trip margin data to generate a trip margin, and determining if the trip margin is acceptable relative to the model trip margin.

A method for diagnosing the state of wear of an electrical switching unit including an electrical unit monitoring phase. The monitoring phase uses learning data loaded previously and representative of the type of electrical unit, and initialization data corresponding to the unit to be monitored and stored in an initialization phase. The monitoring phase includes the measurement and the acquisition of a measurement curve on opening the electrical unit, the determination of the value of local descriptors of the measurement curve as a function of values of the measurement curve, of initialization data and of learning data, the determination of the positioning of local descriptor values, the determination of an overall state class as a function of the positioning values. The device and the electrical unit implement the method.

Systems and method for automated self-testing of a protective device for a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit may include a DC blocking component, a switch assembly, and a spark gap assembly each positioned in parallel between the transformer neutral and ground, a switch assembly. The system may further include various testing circuits configured within the protection circuit and switches which when actuated inject a signal to test various components in the protective device.

A device includes an electro-mechanical switching device having an open-circuit and closed-circuit conditions and a path of least resistance having a path input and a path output with the switching device between the input and the output. The device includes a bypass power switch device that comprises a solid-state circuit interrupter and that is configured to conduct current between the input and the output in response to an open-circuit condition of the switching device. The device includes a current sensor that is connected to the output and configured to detect a fault current event. The device includes an actuator that is coupled to the switching device and a controller that is configured to generate a trigger signal to activate the actuator to cause the open-circuit condition of the switching device and to interrupt the fault current event by the power switch device, based on the detected fault current event.

A device includes an electro-mechanical switching device having an open-circuit and closed-circuit conditions and a path of least resistance having a path input and a path output with the switching device between the input and the output. The device includes a bypass power switch device that comprises a solid-state circuit interrupter and that is configured to conduct current between the input and the output in response to an open-circuit condition of the switching device. The device includes a current sensor that is connected to the output and configured to detect a fault current event. The device includes an actuator that is coupled to the switching device and a controller that is configured to generate a trigger signal to activate the actuator to cause the open-circuit condition of the switching device and to interrupt the fault current event by the power switch device, based on the detected fault current event.

A switchgear system includes a switchgear frame and a truck carrying a circuit breaker, which includes a breaker housing, a fixed electrical contact and a movable electrical contact mounted within the breaker housing, an actuator piston connected to the movable electrical contact, and a drive assembly coupled to the actuator piston. A sensor circuit is mounted on the switchgear frame under the truck and aligned with the circuit breaker and configured to acquire displacement data of the actuator piston when in a contact testing position. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.

A switchgear system includes a switchgear frame and a truck carrying a circuit breaker, which includes a breaker housing, a fixed electrical contact and a movable electrical contact mounted within the breaker housing, an actuator piston connected to the movable electrical contact, and a drive assembly coupled to the actuator piston. A sensor circuit is mounted on the switchgear frame under the truck and aligned with the circuit breaker and configured to acquire displacement data of the actuator piston when in a contact testing position. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.

A method includes measuring, by at least one processor, a time at which control circuitry sends an instruction to a switch structured to control transmission of electrical power. The method further includes sensing, by at least one sensor, a change in position of the switch in response to the instruction, and determining, by the at least one processor, a delay between the time at which the control circuitry sends the instruction and a time at which the change in position occurs. The method still further includes recording, by the at least one processor, the delay in a delay measurement queue and taking, by the at least one processor, an action with respect to the switch in response to the delay measurement queue.