An electrically insulative case includes a door arranged to move between an opened position and a closed position and a rack mechanism arranged to move between an ON position and an OFF position. The electrically insulative case further includes an interlock including a plunger arranged to move between a locked position and an unlocked position. The interlock also includes an engagement mechanism that is coupled to the plunger. The engagement mechanism is arranged to move between a first position in which the engagement mechanism is spaced from the rack mechanism and a second position in which the engagement mechanism is engaged with the rack mechanism. The door is inhibited from moving to the opened position when the plunger is in the locked position. The plunger is arranged to move to the locked position when the engagement mechanism is in the second position and the rack mechanism is in the ON position.

A disconnect switch is disclosed with an integrated thermal breaker that can be disposed between a source of power and a circuit to be protected. The disconnect switch can comprise a housing, a first terminal coupled to a power source and a second terminal coupled to a load. The first terminal and the second terminal can be partially included in the housing. The disconnect switch comprises a bi-metal thermal conductive element made from at least two metal sheets with different thermal expansion coefficients and having a concave shape that engages the first and second terminals. Upon occurrence of an overload condition, heat flowing through the bi-metal thermal conductive element causes the concave shape to retract to a convex shape and disengage the bi-metal thermal conductive element from the first and the second terminals.

A circuit breaker includes an electrically insulative case including a first end and a second end opposite the first end. The circuit breaker further includes an end cover selectively installable on both the first and second ends of the electrically insulative case. The end cover includes a wall defining at least one opening for receiving a removable shield, a first end connectable to the electrically insulative case first end, and a second end connectable to the electrically insulative case second end.

An electronic circuit breaker may include a monitoring circuit configured to monitor and respond to a power supply and/or detection circuit failure within the electronic circuit breaker. In some embodiments, the monitoring circuit may monitor a regulated DC voltage provided by the detection circuit within the electronic circuit breaker. A response to a power supply and/or detection circuit failure may include interrupting current flow between an electrical power source and an electrical circuit protected by the electronic circuit breaker. Methods of monitoring and responding to a power supply and/or detection circuit failure within an electronic circuit breaker are also provided, as are other aspects.

An electronic circuit breaker may include a monitoring circuit configured to monitor and respond to a power supply and/or detection circuit failure within the electronic circuit breaker. In some embodiments, the monitoring circuit may monitor a regulated DC voltage provided by the detection circuit within the electronic circuit breaker. A response to a power supply and/or detection circuit failure may include interrupting current flow between an electrical power source and an electrical circuit protected by the electronic circuit breaker. Methods of monitoring and responding to a power supply and/or detection circuit failure within an electronic circuit breaker are also provided, as are other aspects.

A front-accessible bus-connection mounting frame assembly in a draw out switchgear cabinet is fastened to the back wall of the breaker cabinet. The frame assembly provides for insertion and bayonet mounting of a primary bus connector's cylindrical conductor onto the mounting frame. The primary bus connector is bayonet mounted on the internal ribs of a central cylinder of the mounting frame assembly. The primary bus connector is then fixed in position by bolts front mounted down the central cylinder and out through a bus riser fitted at the back of the mounting frame assembly to establish electrical continuity. The central cylinder further provides a current transformer bushing tube around the primary bus connector and necessary flanges to mount the mounting frame assembly to the back wall and secure the current transformers around the bushing.

A front-accessible bus-connection mounting frame assembly in a draw out switchgear cabinet is fastened to the back wall of the breaker cabinet. The frame assembly provides for insertion and bayonet mounting of a primary bus connector's cylindrical conductor onto the mounting frame. The primary bus connector is bayonet mounted on the internal ribs of a central cylinder of the mounting frame assembly. The primary bus connector is then fixed in position by bolts front mounted down the central cylinder and out through a bus riser fitted at the back of the mounting frame assembly to establish electrical continuity. The central cylinder further provides a current transformer bushing tube around the primary bus connector and necessary flanges to mount the mounting frame assembly to the back wall and secure the current transformers around the bushing.

A front-accessible bus-connection mounting frame assembly in a draw out switchgear cabinet is fastened to the back wall of the breaker cabinet. The frame assembly provides for insertion and bayonet mounting of a primary bus connector's cylindrical conductor onto the mounting frame. The primary bus connector is bayonet mounted on the internal ribs of a central cylinder of the mounting frame assembly. The primary bus connector is then fixed in position by bolts front mounted down the central cylinder and out through a bus riser fitted at the back of the mounting frame assembly to establish electrical continuity. The central cylinder further provides a current transformer bushing tube around the primary bus connector and necessary flanges to mount the mounting frame assembly to the back wall and secure the current transformers around the bushing.

A front-accessible bus-connection mounting frame assembly in a draw out switchgear cabinet is fastened to the back wall of the breaker cabinet. The frame assembly provides for insertion and bayonet mounting of a primary bus connector's cylindrical conductor onto the mounting frame. The primary bus connector is bayonet mounted on the internal ribs of a central cylinder of the mounting frame assembly. The primary bus connector is then fixed in position by bolts front mounted down the central cylinder and out through a bus riser fitted at the back of the mounting frame assembly to establish electrical continuity. The central cylinder further provides a current transformer bushing tube around the primary bus connector and necessary flanges to mount the mounting frame assembly to the back wall and secure the current transformers around the bushing.

A tripping shaft apparatus for a circuit breaker. Tripping shaft apparatus includes a rigid shaft portion and a polymer shaft portion molded onto the rigid shaft portion, wherein the polymer shaft portion includes a first molded lever. At least one other lever is a part of the tripping shaft apparatus. A torsion spring is received over the shaft between the first molded lever and the second lever providing an integral torsion spring positioned between the levers. Circuit breaker tripping assemblies and methods of assembling a circuit breaker tripping assembly are provided, as are other aspects.