The invention relates to a circuit breaker for a low-voltage circuit having input and output terminals for conductors of the low-voltage circuit. Within the circuit breaker, the low-voltage circuit can be interrupted or closed. The circuit breaker also has a current sensor which determines the level of the electrical current in the low-voltage circuit and is connected to an electronic trigger unit which has a display for displaying information and interrupts the low-voltage circuit if current limit values or current-time limit values are exceeded. The display is designed to be removable.

Proposed is an earth leakage breaker having a built-in trip module type circuit breaker, which is installed at a line between a power supply and a load and has a trip module configured to cut the line off, the earth leakage breaker including: a CT installed on the line and configured to monitor an instantaneous current; and a control circuit unit comprising: an operation module configured to receive an instantaneous current sensed by the CT, to measure an instantaneous current value per unit time, and to calculate a slope of the instantaneous current per unit time; a determination module configured to determine a case as an overload state, the case having the slope exceeding an overcurrent determination value A, and to cause an overload state determination signal to be output; and an output module configured to output a trip module actuation signal according to the overload state determination signal of the determination module and to cut off the line, and accordingly, the earth leakage breaker causes the trip module to be actuated according to an instantaneous current slope.

A system and apparatus for maintaining the desired synchronous and asynchronous A and B auxiliary electrical circuits, respectively, by use of connector block halves, one connector block half being connected to wiring out for auxiliary circuitry and being secured to the movable circuit breaker and the other auxiliary connector block half also being connecting to wiring out for auxiliary circuitry and secured to the relatively stationary wall or surface of the cubicle, where the connector block halves have some portion of its contacts of the “make before break” type so that the A and B auxiliary circuits operate as intended when the connector halves are connected and the A and B auxiliary circuits still reflect the proper condition, synchronous or asynchronous, of the A and B circuits, respectively, even when the auxiliary connector block halves are physically and/or electrically separated from one another.

A fusible switch disconnect device includes a housing adapted to receive at least one fuse therein, and a switchable contact for connecting the fuse to circuitry. A tripping mechanism and control circuitry are provided to move the switchable contact to an open position in response to a predetermined electrical condition.

A hybrid load protection apparatus (1) comprises a primary power supply path (1A) between input terminal and output terminals (2, 3) and a controllable mechanical switch (5A) connected in series with a primary coil (4A-1) coupled inductively to a secondary coil (4A-2) providing a voltage, U.sub.A, corresponding to a current rise speed of the electrical current flowing through the primary path (1A). The voltage, U.sub.A, is applied directly to a driver input (IN) of a first driver circuit (6A) to trigger automatically a switch-off of the mechanical switch (5A) within a first switch-off period (Δt1) to interrupt the primary power supply path (1A). A secondary power supply path (1B) is provided in parallel to the primary path (1A) and having a further coil (4B) connected in series with a semiconductor power switch (5B). wherein a second driver circuit (6B) associated with the secondary path (1B) detects an increasing electrical current, I, flowing through the secondary path (1B) caused by the interruption of the primary current path (1A) on the basis of a voltage drop (ΔU.sub.4) generated by the further coil (4B) and a non-linear voltage drop (ΔU.sub.5) along the semiconductor power switch (5B) applied as a sum voltage (U.sub.B) directly to a driver input (DESAT) at a high voltage side of the second analog driver circuit (6B) to trigger automatically a switch-off of the semiconductor power switch (5B) within a second switch-off period (Δt2) to interrupt the secondary power supply path (1B).

A solid-state circuit breaker (SSCB) comprises a breaker housing, line-in and line-out terminals and one or more solid state switching components. The SSCB further comprises an air gap disposed between the line-in and line-out terminals and coupled in series with the solid-state switching components to complete a current conducting path when closed. The air gap includes an air gap driving mechanism. The solid-state circuit breaker further comprises an air gap actuator to interact with the air gap driving mechanism. The SSCB further comprises a controller that controls the air gap actuator and is configured to: (a). send a tripping signal to the air gap actuator and the one or more solid state switching components at substantially the same time or (b). send a tripping signal to the air gap actuator a short amount of time earlier than sending the tripping signal to the one or more solid state switching components.

In an electrical distribution system including a solid-state circuit breaker (SSCB) and one or more downstream mechanical circuit breakers (CBs), a solid-state switching device in the SSCB is repeatedly switched ON and OFF during a short circuit event, to reduce a root-mean-square (RMS) value of the short circuit current. The resulting pulsed short circuit current is regulated in a hysteresis control loop, to limit the RMS to a value low enough to prevent the SSCB from tripping prematurely but high enough to allow one of the downstream mechanical CBs to trip and isolate the short circuit. Pulsing is allowed to continue for a maximum short circuit pulsing time. Only if none of the downstream mechanical CBs is able to trip to isolate the short circuit within the maximum short circuit pulsing time is the SSCB allowed to trip.

A fusible switch disconnect device includes a housing adapted to receive at least one fuse therein, and a switchable contact for connecting the fuse to circuitry. A tripping mechanism and control circuitry are provided to move the switchable contact to an open position in response to a predetermined electrical condition.

A recloser including a circuit interrupter including a first contact and a second contact movable relative to the first contact between a closed position and an open position and an actuator coupled to the circuit interrupter, the actuator including a plunger coupled to the second contact for closing and opening the circuit interrupter and a single coil used for driving the plunger. The recloser further includes a sensor board supported by the actuator, the sensor board including a plurality of position sensors for detecting a position of the plunger, an external indicator for indicating a condition of the circuit interrupter, the external indicator including a first display portion that indicates the closed position and a second display portion moveable relative to the first display portion and that indicates the open position, and a handle for mechanically opening and closing the circuit interrupter without any electrical assistance.

A circuit interrupter (100) for interrupting an electric current in an electrical line is disclosed. The circuit interrupter (100) includes a controller (102) for detecting a breaker fault condition. The controller (102) is connected to a first semiconductor switch (114) for energizing a solenoid (104) to trip a circuit breaker on detection of the breaker fault condition, wherein a winding of the solenoid (104) is energized to trip the circuit breaker, and wherein the solenoid (104) is configured with a center tap in the winding, such that there are two parts (106, 108) in the winding separated by the center tap. Further, upon detection of an open condition in a part of the winding, the controller (102) is configured to provide a trip signal to the circuit breaker using the other part of the winding.