FIELD: electricity.
SUBSTANCE: vacuum circuit breaker to be used in medium- and high-voltage circuits comprises at least one body (1) of a pole part, where vacuum insert (2) is placed with a pair of respective coaxial electric contacts (3, 4) inside it. A fixed electrical contact (3) is coupled electrically to the upper clamp (5) at the body (1) of a pole part, while axis-movable electric contact (4) is coupled electrically to the lower clamp (6) at the body (1) of a pole part and driven by insulated traction (7), which passes through a protective plate (8) placed at the bottom hole in the body (1) of pole part. The protective plate (8) is made of rigid plastic insulating material, at that along perimeter of the protective plate (8) there is at least one moulded sealing ring (9, 9a, 9b) made of elastic material.
EFFECT: developing a circuit breaker with simple and effective protection device against electric breakdowns between the lower electrical clamp and edges of the pole part body.
10 cl, 7 dwg
