Low-voltage switch pole

1 . A switch pole for a low-voltage switching device comprising:

an insulating casing defining an internal space with a contact region and an arc extinguishing region of said switch pole;

a first pole terminal and a second pole terminal couplable with corresponding line conductors of an electric line;

a fixed contact assembly arranged in said contact region and including a plurality of fixed electric contacts electrically connected to said first pole terminal, said fixed electric contacts including one or more first fixed contacts and one or more second fixed contacts electrically insulated from said first fixed contacts;

a movable contact assembly arranged in said contact region and including a plurality of movable electric contacts electrically connected to said second pole terminal, said movable electric contacts including one or more first movable contacts and one or more second movable contacts, said movable contact assembly being reversibly movable around a rotation axis, so that said first movable contacts can be coupled to or decoupled from said first fixed contacts and said second movable contacts can be coupled to or decoupled from said second fixed contacts, when said movable contact assembly moves about said rotation axis; and

an arc chamber arranged in said arc extinguishing region and comprising a plurality of arc-breaking elements,

wherein said switch pole comprises a magnetic field generation arrangement including a first coil conductor and a second coil conductor wound around a winding axis parallel to the rotation axis of said movable contact assembly, said first and second coil conductors being spaced one from another along said winding axis and being electrically connected in series between said second fixed contacts and said first pole terminal,

wherein said magnetic field generation arrangement is configured to generate a magnetic field during an opening maneuver of the switch pole, the generated magnetic field being directed in such a way to make electric arcs, which arise between said fixed contact assembly and said movable contact assembly under separation, displace towards the arc extinguishing region of said switch pole, and

wherein the switch pole comprises a magnetic shield arrangement arranged at an opposite side of the switch pole relative to said fixed contact assembly, said magnetic shield arrangement configured to confine the magnetic field generated by said magnetic field generation arrangement, during the opening maneuver of said switch pole.

2 . The switch pole according to claim 1 , wherein said first and second coil conductors are arranged at opposite lateral walls of said insulating casing.

3 . The switch pole according to claim 1 , wherein:

said first and second coil conductors comprise first and second coil terminals and third and fourth coil terminals respectively,

the first coil terminal of said first coil conductor is electrically connected to said second fixed contacts through a first electric bus,

the second coil terminal of said first coil conductor is electrically connected to the third coil terminal of said second coil conductor through a second electric bus, and

the fourth coil terminal of said second coil conductor is electrically connected to said first pole terminal through a third electric bus.

4 . The switch pole according to claim 3 , wherein said switch pole comprises an additional casing structure to accommodate said first and second coil conductors and said first, second, and third electric buses, said additional casing structure being fixed to said insulating casing.

5 . The switch pole according to claim 3 , wherein a central magnetic portion is arranged on a first support fixed to said insulating casing at a front wall of the insulating casing and second magnetic portions are arranged on corresponding second supports fixed to an additional casing structure, at opposite lateral walls of said insulating casing.

6 . The switch pole according to claim 1 , wherein said magnetic shield arrangement comprises a U-shaped magnetic yoke having a central magnetic portion arranged at a front wall of said insulating casing and a pair of lateral magnetic portions arranged at opposite lateral walls of said insulating casing.

7 . The switch pole according to claim 6 , wherein said central magnetic portion is arranged on a first support fixed to said insulating casing at said front wall and second magnetic portions are arranged on corresponding second supports fixed to an additional casing structure, at opposite lateral walls of said insulating casing.

8 . The switch pole according to claim 1 , wherein said movable contact assembly is reversibly movable, about said rotation axis, between a first position, which corresponds to a closed condition of said switch pole, and a second position, which corresponds to an open condition of said switch pole.

9 . The switch pole according to claim 8 , wherein, when said movable contact assembly is in said first position:

said first movable contacts are coupled to said first fixed contacts; and

said second movable contacts are decoupled from said second fixed contacts.

10 . The switch pole according to claim 9 , wherein, during the opening maneuver of said switch pole, said movable contact assembly moves from said first position to a first intermediate position, and wherein:

said first movable contacts are coupled to said first fixed contacts, and said second movable contacts are coupled to said second fixed contacts.

11 . The switch pole according to claim 10 , wherein, during the opening maneuver of said switch pole, said movable contact assembly subsequently moves from said first intermediate position to a second intermediate position, and wherein:

said first movable contacts are decoupled from said first fixed contacts, and

said second movable contacts are coupled to said second fixed contacts.

12 . The switch pole according to claim 11 , wherein, during the opening maneuver of said switch pole, said movable contact assembly subsequently moves from said second intermediate position to said second position.

13 . The switch pole according to claim 9 , wherein when said movable contact assembly is in said second position:

said first movable contacts are decoupled from said first fixed contacts; and

said second movable contacts are decoupled from said second fixed contacts.

14 . The switch pole according to claim 8 , wherein when said movable contact assembly is in said second position:

said first movable contacts are decoupled from said first fixed contacts; and

said second movable contacts are decoupled from said second fixed contacts.

15 . The switch pole according to claim 14 , wherein, during the opening maneuver of said switch pole, said movable contact assembly moves from said first position to a first intermediate position, and wherein:

said first movable contacts are coupled to said first fixed contacts, and

said second movable contacts are coupled to said second fixed contacts.

16 . The switch pole according to claim 15 , wherein, during the opening maneuver of said switch pole, said movable contact assembly subsequently moves from said first intermediate position to a second intermediate position, and wherein:

said first movable contacts are decoupled from said first fixed contacts, and

said second movable contacts are coupled to said second fixed contacts.

17 . The switch pole according to claim 16 , wherein, during the opening maneuver of said switch pole, said movable contact assembly subsequently moves from said second intermediate position to said second position.

18 . A low-voltage switching device, comprising:

at least a switch pole, comprising:

an insulating casing defining an internal space with a contact region and an arc extinguishing region of said switch pole;

a first pole terminal and a second pole terminal couplable with corresponding line conductors of an electric line;

a fixed contact assembly arranged in said contact region and including a plurality of fixed electric contacts electrically connected to said first pole terminal, said fixed electric contacts including one or more first fixed contacts and one or more second fixed contacts electrically insulated from said first fixed contacts;

a movable contact assembly arranged in said contact region and including a plurality of movable electric contacts electrically connected to said second pole terminal, said movable electric contacts including one or more first movable contacts and one or more second movable contacts, said movable contact assembly being reversibly movable around a rotation axis, so that said first movable contacts can be coupled to or decoupled from said first fixed contacts and said second movable contacts can be coupled to or decoupled from said second fixed contacts, when said movable contact assembly moves about said rotation axis; and

an arc chamber arranged in said arc extinguishing region and comprising a plurality of arc-breaking elements,

wherein said switch pole comprises a magnetic field generation arrangement including a first coil conductor and a second coil conductor wound around a winding axis parallel to the rotation axis of said movable contact assembly, said first and second coil conductors being spaced one from another along said winding axis and being electrically connected in series between said second fixed contacts and said first pole terminal,

wherein said magnetic field generation arrangement is configured to generate a magnetic field during an opening maneuver of the switch pole, the generated magnetic field being directed in such a way to make electric arcs, which arise between said fixed contact assembly and said movable contact assembly under separation, displace towards the arc extinguishing region of said switch pole, and

wherein the switch pole comprises a magnetic shield arrangement arranged at an opposite side of the switch pole relative to said fixed contact assembly, said magnetic shield arrangement configured to confine the magnetic field generated by said magnetic field generation arrangement, during the opening maneuver of said switch pole.