Winding for a contact of a medium-voltage vacuum circuit-breaker with improved arc extinction, and an associated circuit-breaker and vacuum circuit-breaker, such as an ac generator disconnector circuit-breaker

An electrical contact for a medium voltage vacuum circuit-breaker extending along an longitudinal axis Y and comprising:

• a mechanical connection portion that extends along the longitudinal axis Y;
• a contact body that includes:
• a first winding based on a material of low electrical resistance and of a diameter typically greater than 90 mm, intended to generate a magnetic field in an electrical contact for a medium voltage vacuum circuit-breaker, the first winding comprising a first hollow cylinder including helical slots that are empty of material, arranged in parallel around its longitudinal axis, and that open out both to the hollow inside and to the outside of the first hollow cylinder, the angular length of each helix of the first winding is less than 360°;
• and
• a circular plate that has a diameter equal to the outside diameter of the first hollow cylinder, said plate also being centered on the longitudinal axis Y and being fastened to the end of the first hollow cylinder that is opposite from the end fastened to the mechanical connection portion.