To provide a tap selector having a roller contact device, which suppresses material cost and processing cost for a current collection contact and maintains contact resistance for a long period even in insulating oil.

While the current collection contact 2, a tap changeover support contact 3 and a fixed contact 4 are formed to be as thick as each other, the roller contact device 5 is made to roll while sliding. Specifically, on an upper side of a structure whose vertical shape is symmetrical, the direction of the axis L2 of a roller shaft 12 is determined so that the axis L2 of the roller shaft 12 does not pass one point P where a straight line L3 passing a contact point A of a contact portion 23 for the fixed contact and a contact point C of a contact portion 25 for the current collection contact intersects with the axis L1 of an insulating rotary shaft 1, and diameters of the respective contact points A, B and C of the contact portion 23 for the fixed contact portion 23 for the fixed contact, a contact portion 24 for the tap changeover support contact 3, and the contact portion 25 for the current collection contact are determined so that the state where the axis L2 does not pass the one point P is maintained.

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