Hybrid circuit breaker with axial blowout coil

A medium voltage circuit breaker comprising:

• a sealed enclosure filed with a high dielectric strength gas;
• a pair of main contacts disposed within said sealed enclosure;
• a vacuum switch disposed within said sealed enclosure, said vacuum switch comprising a cylindrical housing comprised of an electrically insulating material, first and second end caps sealing off respective first and second opposite ends of the cylindrical housing, a pair of arcing contacts disposed within an internal volume defined by said cylindrical housing and said first and second end caps, said arcing contacts being electrically connected in parallel to said main contacts, each of said pairs of main and arcing contacts being operable between open and closed positions, said arcing contacts being separated from each other by a gap extending along a direction parallel to the longitudinal axial direction of the cylindrical housing in the open position, wherein said first end cap comprises an annular groove which has a diameter smaller than that of the cylindrical housing such that the annular groove is disposed radially inwardly from said cylindrical housing and longitudinally axially within said cylindrical housing, said annular groove being substantially coaxial with said cylindrical housing and extending toward said gap;
• an operating mechanism mechanically connected to said main contacts and to said arcing contacts, said operating mechanism opening the arcing contacts after the main contacts open, and closing the arcing contacts before the main contacts close;
• and
• a ring-shaped coil disposed within said annular groove in said first end plate, said ring-shaped coil being sealed off from said internal volume of said vacuum switch by said first end plate.