Tank-type circuit breaker
A tank-type circuit breaker includes a cylindrical grounded tank in which an insulating gas is sealed, a vacuum valve insulated and supported in the grounded tank and including a movable-side contact and a fixed-side contact, a movable conductor electrically connected to the movable-side contact, a fixed conductor electrically connected to the fixed-side contact, a movable-side external conductor and a fixed-side external conductor disposed in a pair of bushings extending above the grounded tank, a movable-side frame electrically connecting the lower end of the movable-side external conductor to the movable conductor, and a fixed-side frame electrically connecting the lower end of the fixed-side external conductor to the fixed conductor. The fixed-side frame and the fixed-side external conductor are connected via at least two springs arranged in series along an extending direction of the fixed-side external conductor, so that the fixed-side frame is suspended and supported by the fixed-side external conductor.
1 . A circuit breaker, comprising:
a cylindrical grounded tank in which an insulating gas is sealed;
a contact insulated and supported in the grounded tank and including a movable-side contact and a fixed-side contact;
a movable conductor electrically connected to the movable-side contact;
a fixed conductor electrically connected to the fixed-side contact;
a movable-side external conductor and a fixed-side external conductor disposed in a pair of bushings extending above the grounded tank, respectively;
a movable-side frame configured to electrically connect a lower end of the movable-side external conductor to the movable conductor;
a fixed-side frame configured to electrically connect a lower end of the fixed-side external conductor to the fixed conductor;
a movable-side insulating support tube configured to insulate and support the movable-side frame in the grounded tank;
an annular portion formed of an annular plate and fixed at an outer peripheral portion to the fixed-side frame inside the fixed-side frame;
a rod fixed to a distal end portion of the fixed-side external conductor and extending in an extending direction of the fixed-side external conductor; and
an annular suppressing plate fixed at a central portion to a distal end portion of the rod, wherein
the fixed-side frame and the fixed-side external conductor are connected via at least two elastics arranged in series along the extending direction of the fixed-side external conductor, so that the fixed-side frame is suspended and supported by the fixed-side external conductor, and wherein
the elastics include a first elastic and a second elastic configured to generate, when compressed, a reaction force in a direction opposite to a compressed direction;
the first elastic is disposed between the fixed-side external conductor and the annular portion; and
the second elastic is disposed between the annular portion and the annular suppressing plate.
2 . The circuit breaker according to claim 1 , wherein the elastics are coil springs or disc springs.
3 . The circuit breaker according to claim 1 , wherein
the contact is a vacuum valve.
4 . The circuit breaker according to claim 1 , wherein
the fixed-side frame includes an inner wall surface forming a cylindrical area;
the lower end of the fixed-side external conductor is inserted into the cylindrical area movably along an axial direction;
the at least two elastics are arranged in series from a lower end side of the fixed-side external conductor along the extending direction of the fixed-side external conductor; and
an outer wall surface of the fixed-side external conductor and the inner wall surface of the fixed-side frame are electrically connected via a current-carrying contact.
5 . The circuit breaker according to claim 4 , wherein
the annular portion is a protrusion protruding from the inner wall surface of the fixed-side frame toward a central portion of the cylindrical area.