A solid-state circuit breaker (SSCB) with self-diagnostic, self-maintenance, and self-protection capabilities includes: a power semiconductor device; an air gap disconnect unit connected in series with the power semiconductor device; a sense and drive circuit that switches the power semiconductor device OFF upon detecting a short circuit or overload of unacceptably long duration; and a microcontroller unit (MCU) that triggers the air gap disconnect unit to form an air gap and galvanically isolate an attached load, after the sense and drive circuit switches the power semiconductor device OFF. The MCU is further configured to monitor the operability of the air gap disconnect unit, the power semiconductor device, and other critical components of the SSCB and, when applicable, take corrective actions to prevent the SSCB and the connected load from being damaged or destroyed and/or to protect persons and the environment from being exposed to hazardous electrical conditions.

A circuit breaker includes at least one moveable contact. The moveable electrode is operably connected to a Thomson coil actuator that can separate and open the contacts of the circuit breaker. A sensor senses current or voltage in the circuit breaker. When a condition exists that triggers an opening action, a controller will use select a current level to apply to the Thomson coil actuator. The selected current level will vary based on the sensed current or voltage level. The controller will cause a driver to apply the selected current level to the Thomson coil actuator, and it will cause the contacts to separate and open. If the circuit breaker is a vacuum interrupter, the vacuum interrupter may employ a multi-section bellows in which each section has unique structural characteristics as compared to the other sections, so that different sections will dominate as the Thomson coil's speed of operation varies.

A particularly reliable quick release latch and a release mechanism, as well as a quick grounding device or short circuiter, is particularly suited for low, medium, and/or high-voltage applications.

A power circuit breaker has a housing defining a first passage and a cross passage through the housing. A bus bar extends through the cross passage and is configured to transmit electric power and/or break transmission of the electric power through the housing. The bus bar includes at least an input section, a coin or center section, and an output section that are separable from each other. The housing aligns a solenoid piston within the first passage of the housing. The solenoid has a piston with two opposite ends, and one of the ends operates as a plunger to separate the sections of the bus bar when the solenoid is actuated. The plunger moves the coin or center section of the bus bar out of contact with the input section and the output section of the bus bar to break electrical transmission across the bus bar.

A particularly reliable quick release latch and a release mechanism, as well as a quick grounding device or short circuiter, is particularly suited for low, medium, and/or high-voltage applications.

Provided herein is an improved solenoid electrical switch. In some embodiments, a solenoid electrical switch may include a plunger at least partially disposed in a central aperture of a solenoid for rotation and axial reciprocation between at least two positions into and out of the central aperture relative to a magnetic coupling member. The plunger may include a first component including a main body and a central slot within the main body, and a second component at least partially disposed within the central slot, wherein the second component may include an engagement surface engaged with an inner surface of the central slot.

A solid-state circuit breaker (SSCB) with self-diagnostic, self-maintenance, and self-protection capabilities includes: a power semiconductor device; an air gap disconnect unit connected in series with the power semiconductor device; a sense and drive circuit that switches the power semiconductor device OFF upon detecting a short circuit or overload of unacceptably long duration; and a microcontroller unit (MCU) that triggers the air gap disconnect unit to form an air gap and galvanically isolate an attached load, after the sense and drive circuit switches the power semiconductor device OFF. The MCU is further configured to monitor the operability of the air gap disconnect unit, the power semiconductor device, and other critical components of the SSCB and, when applicable, take corrective actions to prevent the SSCB and the connected load from being damaged or destroyed and/or to protect persons and the environment from being exposed to hazardous electrical conditions.

A smart accessory device includes an actuator and is designed to be used to actuate an operating mechanism of a circuit breaker in order to either open or close the separable contacts of the circuit breaker. The accessory can be one of a shunt trip, spring release, or under voltage release device. The actuator includes a solenoid and plunger. The accessory determines the operating condition of the actuator based on how much current flows through the coil when the power source provides power to the accessory device, and continually executes a coil diagnostic to determine the operating condition of the coil while power is being provided to the accessory device. If the accessory fails to trip the circuit breaker when required, the accessory can determine whether the failure was due to either of the solenoid or the plunger.

A smart accessory device is designed to be used with a circuit breaker so as to be able to actuate an operating mechanism of the circuit breaker in order to either open or close the separable contacts of the circuit breaker. The accessory device can be one of a shunt trip, spring release, or under voltage release device. The accessory device continually executes diagnostics to determine whether the power being supplied by an external power source is sufficient to enable the accessory device to actuate the operating mechanism of the associated circuit breaker. If the accessory device determines that the power being supplied by the external source is insufficient, the device triggers an alarm in order to notify a user that the power source is not meeting the power requirements of the device.

A leakage current protection device includes a shell and a core assembly disposed within the shell. The core assembly includes a control circuit board, a trip assembly disposed on the control circuit board, and an input end and an output end connected to the trip assembly. The trip assembly includes a first driving member movable linearly in a first direction and a second driving member pivotable around a pivotal support axis, where the first and second driving members are mechanically engaged with each other and move together with each other. The second driving member has two driving points configured to move in a second direction as the second driving member pivots, the second direction being non-parallel to the first direction. Movements of the two driving points of the second driving member in the second direction are operable to electrically connect or disconnect the input and output ends.