Electromagnetic arc extinction apparatus for switchgear

An electromagnetic arc extinction apparatus for switchgear, comprising:

• an arc chamber defined by an electrically insulating material and having a cavity extending along a helix so as to allow a quenching arc in the form of a helix to be moved in a radial direction, said cavity having a pitch which is at least 10 times smaller than the diameter of the arc chamber measured over the cross-section thereof;
• an axial channel extending axially through said arc chamber;
• two electrodes at least in part situated in said axial channel and arranged in alignment with the axis of said arc chamber and adapted to form said quenching arc;
• and
• a wire adapted to connect said electrodes, said wire being disposed in said axial channel of said arc chamber and used as a fusible element, said wire having a diameter substantially equal to the diameter of said axial channel.

An electromagnetic arc extinction apparatus for switchgear, comprising:

• an arc chamber defined by an electrically insulating material and having a cavity extending along a helix so as to allow a quenching arc in the form of a helix to be moved in a radial direction, said cavity having a pitch which is at least 10 times smaller than the diameter of the arc chamber measured over the cross-section thereof;
• an axial channel axially extending through said arc chamber;
• two electrodes at least in part situated in said axial channel and arranged in alignment with the axis of said arc chamber and adapted to form said quenching arc;
• an insert made of electrically insulating material, disposed in said axial channel of said arc chamber and having its diameter substantially equal to the diameter of said axial channel;
• and
• a wire connecting said electrodes, said wire being arranged on said insert in the form of a helix, disposed in said cavity of said arc chamber and used as a fusible element.