A method for determining contact thickness change in a contactor includes sensing a first displacement distance moved by an armature of the contactor from a reference location to a first transition point during a switch-off operation of the contactor at a first contactor life reference time when movable contacts and fixed contacts of the contactor define a first contact thickness. The method further includes sensing a second displacement distance moved by the armature from the reference location to a second transition point during a switch-off operation at a second contactor life reference time that is after the first contactor life reference time when the movable and fixed contacts define a second contact thickness that is less than the first contact thickness. The first displacement distance and the second displacement distance are used to determine a contact thickness change between the first contact thickness and the second contact thickness. A contactor adapted to implement the method is also disclosed.

The disclosure is directed to systems and methods by which the lifetime, e.g., remaining life or amount of life used, of variable use items, such as rechargeable batteries, battery relays, vehicles and power tools, can be determined that takes into account the conditions of the use of the item. The systems and methods involve an algorithm that can be described as accumulating points based on the real time utilization of the item, e.g., rechargeable battery, battery relay, vehicle, or power tool, and when an agreed-upon number of points have been accumulated, the item can be considered to be at end of life or end of warranty.

A method of monitoring a contact force between electrical contacts in a mechanical contactor. The method includes receiving, from a force sensor, a signal including information about a base force sensed by the force sensor between a stationary core and a base; determining a magnitude of the contact force based on the received information; and outputting information based on the determined magnitude to an operator.

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 trip apparatus for a circuit interruption device that comprises a coil operatively connectable to a circuit interruption device. The coil is configured to selectively operate the circuit interruption device to interrupt when a current flowing through the circuit interruption device exceeds a threshold. The trip apparatus also includes a current measuring device configured to selectively measure a coil current flowing through the coil to determine a measured coil current signal. In addition, the trip apparatus includes a monitoring device configured to determine the derivative of the measured coil current signal and to perform a correlation of the derivative of the measured coil current signal and a reference derivative of a reference coil current signal to determine a correlation output. The monitoring device is further configured to compare the correlation output with a reference correlation threshold to determine whether an operating condition of the coil is normal or abnormal.

This disclosure relates to monitoring the condition of electrical/electronic switches over time by monitoring the impedance of the switch. The condition of switches can degrade as they age, which can reduce their performance and may ultimately lead to failure. In many applications, particularly high-voltage applications, the reliable operation of switches may be very important and failures can present a safety risk and cause costly unscheduled system downtime for repairs. It has been realised that as the condition of switches change, their impedance changes, so monitoring the impedance can give a good indication of the condition of the switch, enabling potential faults/failures to be identified early and acted upon pre-emptively.

A circuit for a circuit interrupter is provided. The circuit may in include a first SCR configured to receive a first trigger signal at a gate of the first SCR, a second SCR configured to receive a second trigger signal at a gate of the second SCR, and a third SCR configured to receive a third trigger signal at a gate of the third SCR. A cathode of the first SCR may be connected to an anode of the third SCR. A cathode of the second SCR and a cathode of the third SCR may be connected to a ground. Methods of operating a circuit interrupter and a circuit are also provided.

A system for management of a circuit breaker counter according to an exemplary embodiment of the present invention includes a data processing unit receiving state change data and measurement data of at least one of a circuit breaker and a current measuring unit and transferring an event on the basis of the state change data and measurement data; and a counter managing unit counting a total operation, a load-breaking operation and a fault-breaking operation of the circuit breaker, based on the event and the measurement data, and outputting and storing respective count accumulation values.

An electrical switching device including an input connection land, an output connection land, and a connection member that is capable of switching between a closed position allowing an electric current to flow between the input and output connection lands and an open position preventing the flow of the current between the input and output connection lands. The electrical switching device includes an accelerometer that is capable of measuring a component of an acceleration of the switching device when switching the connection member between the closed and open positions and a control configured to estimate, on the basis of an acceleration measurement signal delivered by the accelerometer, a duration of switching of the connection member between the closed and open positions, and to determine wear on the switching device on the basis of the estimated switching duration.

A circuit breaker characteristic monitoring device monitors the operation of a circuit breaker to estimate the amount of consumption of a movable contact and fixed contacts included in the circuit breaker. The device includes an operating time measurement unit to measure at least one of closing time, which is the time required for the circuit breaker to be closed after starting a closing operation, and opening time, which is the time required for the circuit breaker to be open after starting an opening operation, and a contact consumption amount estimation unit to estimate the amount of consumption of the movable contact and the fixed contacts on the basis of the result of measurement performed by the operating time measurement unit and travel speed of the movable contact during the closing operation or the opening operation for which the measurement result is obtained.