A modular circuit breaker includes a module assembly coupled to a primary assembly. The primary assembly includes a primary housing, separable contacts disposed therein, a first terminal conductor electrically connected to one of the separable contacts, a conductive tab electrically connected to another one of the separable contacts and which extends outward from a first end of the primary housing, an operating mechanism disposed in the primary housing for selectively opening and closing the separable contacts, and a trip mechanism disposed in the primary housing cooperative with the operating mechanism to trip open the separable contacts. The module assembly includes a module housing having a second terminal conductor positioned therein and electrically connected to the conductive tab, a third terminal conductor structured to be electrically connected to a neutral conductor of a load, and a fourth terminal conductor structured to be coupled to a neutral bus.

In one example, a hybrid circuit interrupter may include a three-coil architecture, first coil circuitry, leakage detection circuitry, and a main processing circuit including a processor. The three-coil architecture may include a coil housing, three coils, and a plurality of coil assembly conductors. The coils may be disposed within the coil housing. The coils may be parallel and aligned. The coil assembly conductors may be at least partially disposed within the coil housing. The first coil circuitry may be connected to the first coil and may generate first coil signals. The leakage detection circuitry may be connected to the other coils and may generate a leakage signal. The processor may receive the first coil and leakage signals, determine whether an arc fault exists from the first coil signals, determine whether a ground fault exists from the leakage signal, and generate a first trigger signal if a fault is determined.

The line power and neutral conductors for an arc fault sensing circuit interrupter such as in a miniature circuit breaker are arranged as a rigid conductor surrounding and holding an insulated flexible conductor when passing through the Ground Fault Interrupter current transformer. Voltage metering takes place across the rigid conductor to enable arc fault detection and ground fault detection in the miniature circuit breaker within the space of a single current transformer.

The line power and neutral conductors for a circuit interrupter such as a miniature circuit breaker, using ground fault sensing via a current transformer, are arranged as a rigid conductor formed from a flat plate and surrounding and holding an insulated flexible conductor when passing through the Ground Fault Interrupter current transformer. The rigid conductor can provide a shaped current path to maximize the effectiveness of the current transformer.

A differential electrical protection device D including N-1 phase conductors, each phase conductor including, between an input, or upper, connection land and an output, or lower, connection land, a portion able to pass through a torus and a portion able to pass through a current measurement and supply sensor, the input connection lands being situated in a first plane P1, and the output connection lands extending in a second plane P2, in that the supply and measurement sensors of the N1 phase conductors are each positioned in the space situated between the two planes P1,P2, and wherein it includes an additional phase conductor including an input connection land and an output connection land, a portion able to pass through the torus and a portion able to pass through an additional measurement sensor only measuring the current, this additional measurement sensor being of small size and being positioned directly above the torus in such a way that the assembly formed by the torus and the additional sensor is situated substantially in the space between the two planes P1,P2.

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.

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.

In one example, a hybrid circuit interrupter may include a three-coil architecture, first coil circuitry, leakage detection circuitry, and a main processing circuit including a processor. The three-coil architecture may include a coil housing, three coils, and a plurality of coil assembly conductors. The coils may be disposed within the coil housing. The coil assembly conductors may be at least partially disposed within the coil housing. The first coil circuitry may be connected to the first coil and may generate first coil signals. The leakage detection circuitry may be connected to the other two coils and may generate a leakage signal. The processor may receive the first coil signals, receive the leakage signal, determine whether an arc fault exists based on the first coil signals, determine whether a ground fault exists based on the leakage signal, and generate a first trigger signal if a fault is determined to exist.

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 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.