The present disclosure relates to a circuit breaking unit and an air circuit breaker including the same, and provides a circuit breaking unit, including: a fixed contact; a movable contact moved in a direction toward or away from the fixed contact; a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward; a low runner disposed extending upward from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal; and a magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field between the fixed contact and the movable contact to guide a path of an arc generated when the fixed contact and the movable contact are separated, to the outside.

The present disclosure relates to a circuit breaking unit and an air circuit breaker including the same, and provides a circuit breaking unit, including: a fixed contact; a movable contact moved in a direction toward or away from the fixed contact; a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward; a low runner disposed extending upward from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal; and a magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field between the fixed contact and the movable contact to guide a path of an arc generated when the fixed contact and the movable contact are separated, to the outside.

Disclosed are an arc extinguishing unit and an air circuit breaker comprising the same. An arc extinguishing unit according to an embodiment of the present disclosure includes a gassing material that generates molecules that extinguish an arc when heat generated by the arc is applied. Accordingly, the arc can be extinguished quickly. In addition, the arc extinguishing unit includes an outer support plate made of glass fiber and has a mechanically and thermally strong side plate part, so that burnout due to arc heat can be prevented.

Disclosed are an arc extinguishing unit and an air circuit breaker comprising the same. An arc extinguishing unit according to an embodiment of the present disclosure includes a gassing material that generates molecules that extinguish an arc when heat generated by the arc is applied. Accordingly, the arc can be extinguished quickly. In addition, the arc extinguishing unit includes an outer support plate made of glass fiber and has a mechanically and thermally strong side plate part, so that burnout due to arc heat can be prevented.

An air circuit breaker includes two separable electrical contacts connected to electric current input and output terminals; and a chamber for quenching an electric arc, including a stack of splitter plates that are spaced apart from one another, and lateral walls placed on either side of the stack and including a thermosetting-resin impregnated polyamide woven and being devoid of glass fibres. The quenching chamber furthermore includes protective elements made of crosslinked polyamide, the elements being placed in junction zones between the lateral walls and holding plates, the protective elements covering corners of the splitter plates, which corners are adjacent to the lateral walls, so as to separate these corners of the splitter plates from the electrical contacts.

An air circuit breaker includes two separable electrical contacts connected to electric current input and output terminals; and a chamber for quenching an electric arc, including a stack of splitter plates that are spaced apart from one another, and lateral walls placed on either side of the stack and including a thermosetting-resin impregnated polyamide woven and being devoid of glass fibres. The quenching chamber furthermore includes protective elements made of crosslinked polyamide, the elements being placed in junction zones between the lateral walls and holding plates, the protective elements covering corners of the splitter plates, which corners are adjacent to the lateral walls, so as to separate these corners of the splitter plates from the electrical contacts.

A switch pole for a low-voltage switching device is provided. The switch pole includes an insulating casing defining an internal space with a contact region and an arc extinguishing region of the switch pole, a first pole terminal and a second pole terminal couplable with corresponding line conductors of an electric line, a fixed contact assembly and a movable contact assembly positioned in the contact region and including one or more fixed contacts and one or more movable contacts, respectively, which can be mutually coupled or uncoupled, an arc chamber positioned in the arc extinguishing region and including a plurality of parallel arc-breaking plates, and a magnetic field generation arrangement configured to generate a magnetic field during an opening maneuver of the switch pole.

A switch pole for a low-voltage switching device is provided. The switch pole includes an insulating casing defining an internal space with a contact region and an arc extinguishing region of the switch pole, a first pole terminal and a second pole terminal couplable with corresponding line conductors of an electric line, a fixed contact assembly and a movable contact assembly positioned in the contact region and including one or more fixed contacts and one or more movable contacts, respectively, which can be mutually coupled or uncoupled, an arc chamber positioned in the arc extinguishing region and including a plurality of parallel arc-breaking plates, and a magnetic field generation arrangement configured to generate a magnetic field during an opening maneuver of the switch pole.

A compact disconnect device includes a magnetic arc deflection assembly including at least one set of stacked arc plates and at least one magnet disposed adjacent switchable contacts and establishing a magnetic field across the stacked arc plates. The magnetic arc deflection assembly facilitates reliable connection and disconnection of DC voltage circuitry well above 125 VDC with reduced arcing intensity and duration. The disconnect device may be a compact fusible switch disconnect device having dual sets of switch contacts in the same current path.

A compact disconnect device includes a magnetic arc deflection assembly including at least one set of stacked arc plates and at least one magnet disposed adjacent switchable contacts and establishing a magnetic field across the stacked arc plates. The magnetic arc deflection assembly facilitates reliable connection and disconnection of DC voltage circuitry well above 125 VDC with reduced arcing intensity and duration. The disconnect device may be a compact fusible switch disconnect device having dual sets of switch contacts in the same current path.