Described herein is a switch pole for a low voltage switching device including an insulating casing defining an internal space with a contact area and an arc-extinguishing area of the switch pole, a fixed contact assembly and a movable contact assembly positioned in the contact area and including, respectively, one or more fixed contacts and one or more movable contacts, which can be mutually coupled or uncoupled, and an arc chamber positioned in the arc-extinguishing area that includes a plurality of parallel arc-breaking plates. The insulating casing includes an insulating wall partially separating the contact area from the arc-extinguishing area and a channel connects the contact area to the arc-extinguishing area. The switch pole further includes an additional arc-breaking element anchored to the insulating wall, passing through the channel of the insulating wall and arranged in electrical connection with a terminal arc-breaking plate of the arc chamber.

A switching unit for an electrical switch is disclosed. In an embodiment, the switching unit includes at least one fixed contact and one moveable contact with a current feed, which in order to close or open the current path are respectively brought into mechanical contact with each other or mechanically or magnetically separated from each other. The switching unit further includes at least one extinguishing plate, which affects an electrical arc created when the electrical contacts are opened. The current feed to the moveable contact is designed such that in the open position it directs the current along the electrical arc in the opposite direction to the current direction of the arc.

A circuit breaker having first and second electrical contacts configured to generate an electrical arc upon being separated, an arc chamber surrounding at least a portion of a space between the first and second electric contacts, at least one expansion chamber positioned proximate to the arc chamber, and an arc pressure control valve assembly configured to allow threshold-based flow into and out of the at least one expansion chamber. An arc pressure control valve assembly and method of operating a circuit breaker are described, as are other aspects.

A low voltage switch pole which comprises an insulating casing having lateral walls and a front and a rear wall and defining an internal space with a contact area and an arc extinguishing area, a fixed contact assembly and a movable contact assembly being positioned in said contact area, said movable contact assembly being movable between a closed position in which it is into contact with said fixed contact assembly and an open position in which it is spaced apart from said fixed contact assembly, an arc chamber comprising a plurality of substantially parallel metallic plates inserted into an enclosure made of insulating material being positioned in said arc extinguishing area; the switch pole further comprises an insulating wall which is positioned in said internal space between said contact area and said arc extinguishing area and partially separates said contact area from said arc extinguishing area, a channel connecting said contact area to said arc extinguishing area being provided in said insulating wall.

A circuit breaker having first and second electrical contacts configured to generate an electrical arc upon being separated, an arc chamber surrounding at least a portion of a space between the first and second electric contacts, at least one expansion chamber positioned proximate to the arc chamber, and an arc pressure control valve assembly configured to allow threshold-based flow into and out of the at least one expansion chamber. An arc pressure control valve assembly and method of operating a circuit breaker are described, as are other aspects.

A switch pole for a low voltage switching device including an insulating casing defining an internal space with a contact area and an arc extinguishing area of said switch pole, a fixed contact assembly and a movable contact assembly positioned in said contact area and including, respectively, one or more fixed contacts and one or more movable contacts, which can be mutually coupled or uncoupled, and an arc chamber positioned in said arc extinguishing area and including a plurality of parallel arc-breaking plates and a terminal arc-breaking element, which includes a plate portion arranged in parallel to said arc-breaking plates and having one or more through openings and an elongated portion protruding from said plate portion and extending across said arc-extinguishing area, from said plate portion towards said fixed contact assembly.