A trip bar cam unit for a trip bar is provided. The trip bar cam unit includes a trip bar cam unit body, a cam lever, and a keyed protrusion. The trip bar cam unit body defines an axis of rotation. The cam lever extends generally radially from the trip bar cam unit body. The keyed protrusion corresponds to a trip bar axial bore.

Arc Fault Circuit Interrupter (AFCI), Ground Fault Circuit Interrupter (GFCI) or AF/GF circuit breakers which may optionally have relatively small or compact bodies that have shaped neutral busbars and/or load terminals with an arm that extends through a window of a current transformer in a circuit breaker housing. The neutral busbar and/or load terminal can have a rigid or semi-rigid shaped body with a first segment that extends through the window of the current transformer and a second segment that extends behind the first segment about a printed circuit board. A plug-on, pigtail or bolt-on neutral can engage an electrical pad of the neutral busbar.

A circuit breaker protects an electric low-voltage circuit. The circuit breaker has a housing with grid-side connections and load-side connections for conductors of the low-voltage circuit and a series circuit containing a mechanical separating contact unit and an electronic interruption unit. The separating contact unit is paired with the grid-side connections, and the interruption unit is paired with the load-side connections. The mechanical separating contact unit has a handle for closing and opening contacts. A current sensor is arranged in a conductor path between the separating contact unit and the interruption unit, for ascertaining the level of the current of the low-voltage circuit. The circuit breaker is configured such that when current thresholds and/or current/time thresholds are exceeded, a process for preventing current flow in the low-voltage circuit is initiated. A power supply is connected to conductors of the low-voltage circuit between the grid-side connection and the separating contact unit.

A miniature circuit breaker with quick current breaking capability which includes a miniature circuit breaker body, a current transformer CT1, a zero-sequence current transformer CT2 and a smart controller module. The miniature circuit breaker body is internally provided with a main arc extinguishing chamber, a fixed contact, a movable contact, a tripping mechanism, and a magnetic tripping push rod. The tripping mechanism includes a lock catch, a movable contact rocker arm, a jump pin, a connecting rod, and a tension spring. A rotated-hinge repulsive force structure is applied between the fixed contact and the movable contact. The tripping mechanism is further provided with a torsional spring to press the movable contact close to the fixed contact. A shunt tripping device controlling the miniature circuit breaker switch to be turned off is arranged in the smart controller module.

A trip bar cam unit for a trip bar is provided. The trip bar cam unit includes a trip bar cam unit body, a cam lever, and a keyed protrusion. The trip bar cam unit body defines an axis of rotation. The cam lever extends generally radially from the trip bar cam unit body. The keyed protrusion corresponds to a trip bar axial bore.

A circuit breaker protecting an electric low-voltage circuit includes a housing with grid and load-side circuit connections. A mechanical isolating contact unit paired with load-side connections is series-connected to an electronic interruption unit paired with grid-side connections. A handle operating the isolating contact unit switches a contact opening function preventing current flow or closing function allowing current flow in the low-voltage circuit. Semiconductor-based switch elements of the electronic interruption unit switch to high-ohmic state preventing, or low-ohmic state allowing, current flow in the low-voltage circuit. A current sensor unit ascertains current level of the low-voltage circuit. A control unit is connected to the current sensor unit, isolating contact unit, and electronic interruption unit. Current flow in the low-voltage circuit is prevented upon exceeding current and/or current/time thresholds. An isolating contact unit handle sensor ascertains handle positions.

An electrical protection device, including a movable contact, connected to an electrical circuit, a switching handle, and an electronic control unit. The device further includes an electrical link element, connecting the movable contact and the electronic control unit, a switch, a mechanical link element, connected to the switching handle. The electronic control unit is configured to measure the first voltage and the second voltage, compare the first voltage and the second voltage to determine the cause of opening of the electrical circuit among manual opening and fault opening, send a first signal if the cause of opening is manual opening and send a second and/or third signal if the cause of opening is fault opening.

An electronic device (1) for measuring a differential current (ID) in an electric line (100) having a plurality of conductors, said electronic device comprising: a sensing circuit (2) comprising: a current transformer (21) having a magnetic core (211) through which the conductors of said electric line pass, a secondary winding (212) and an excitation winding (213) along which an excitation current (IE) circulates to polarize said magnetic core (211); an output circuit section (22) electrically connected to said secondary winding (212) and configured to provide a first signal (V1). The electronic device (1) further comprises: a first signal processing block (3) configured to process said first signal (V1) and provide a second signal (VD) indicative of said differential current (ID); a second signal processing block (4) configured to process said second signal (VD) and provide a first measurement signal (IDCM) indicative of the absolute value of a time-invariant component of said differential current (ID); a third signal processing block (5) configured to process said first signal (V1) and provide third and fourth signals (S1, S2) indicating whether said magnetic core (211) operates in a positive and/or in a negative saturation region of the hysteresis loop of said magnetic core; a fourth signal processing block (6) configured to process said third and fourth signals (S1, S2) and provide a second measurement signal (SDC) indicative of the direction of the time-invariant component of said differential current (ID).

A switch box includes a circuit substrate having a conductor pattern, a switching element that is mounted on the circuit substrate, a bus bar having a current input and output portion formed at one end thereof and a mounting portion formed at the other end thereof, the mounting portion being connected to the conductor pattern of the circuit substrate so as to be electrically conducted to the switching element through the conductor pattern, and a magnetic sensor that is mounted on the circuit substrate to detect a magnetic field generated due to a current flowing into the bus bar. The magnetic sensor is disposed in a gap formed between the circuit substrate and the bus bar.

A plug-in summation current transformer module for insertion into a module-overlapping installation space of a multi-pole rail-mounted device that is formed of a plurality of housing modules has a summation current transformer and primary conductors routed through the tubular summation current transformer. The primary conductors have primary conductor ends. A primary conductor holder for fixing the primary conductor ends is fastened to the summation current transformer and adopts a fixing position for holding the primary conductor ends in an assembling position for insertion into a module-overlapping installation space and a releasing position where the primary conductor ends move transversely into a releasing position allowing the primary conductor ends to join into their contacts in the modules.