Abstract: Disclosed is a suspensible external combined on-load tap changer, including: a switch box, a switch body and a motor mechanism, a top box wall of the switch box being opened with a top opening, a top box cover being mounted on the top opening, wherein the switch body is detachably mounted in the switch box and is entirely lifted in and lifted out by the top opening; and the motor mechanism is connected with the switch body in a driving manner. The switch body in the present invention uses a hoisting structure, and the top box wall of the switch box is opened with a top opening with a size large enough, so that the switch body is directly lifted in and lifted out of the switch box from the top opening, and installation and maintenance are easier.

Abstract: Disclosed is a change-over selector with a vacuum arc extinguishing circuit, including a central shaft, a moving contact driven by the central shaft to rotate, and a first static contact and a second static contact circularly arranged on insulation laths of a cage body of the change-over selector, where the moving contact is driven by the central shaft to rotate to switch between the first static contact and the second static contact, the moving contact and the first and second static contacts form a change-over selection main-circuit, a vacuum arc extinguishing sub-circuit including a vacuum tube is connected in parallel to the change-over selection main-circuit, the vacuum tube is opened after the moving contact is separated from the first static contact, and the vacuum tube is closed before the moving contact is electrically connected to the second static contact.

Abstract: Disclosed is a change-over structure between a moving contact and a static contact of a tap selector, including an insulation changer base plate, and further including at least two static contacts, fixed on the insulation changer base plate in at least one column at intervals, where inner ends of at least two static contacts are electrically connected to two tap windings of a transformer respectively; at least one rotation shaft, where at least two moving contacts are evenly distributed on the one rotation shaft, and the at least two moving contacts are electrically connected to each other; and at least one arc-shaped conductor corresponding to the at least two static contacts in at least one column, where the arc-shaped conductor and outer ends of the at least two static contacts in at least one column are located at the same circumference with a center of the rotation shaft as a circle center, and when one of the moving contacts is changed over between the two static contacts, the other moving contact is ce