Abstract: An electrical device for connection to a high-voltage system has a tank filled with insulating fluid. The tank has at least one side wall forming a planar wall portion and a radially outwardly curved bulging/convex portion, which increases the interior volume of the tank. An active part with a core and at least one winding is arranged in the tank. A winding barrier system encloses one or more windings. The convex bulging portion has a shape that complements a portion of the winding barrier system and lies opposite it at a distance, such that the electrical device has increased dielectric strength. An additional barrier is disposed between the winding barrier system and the convex bulging portion which has a round portion, bent radially outwards and facing the convex bulging portion, and two planar flat portions, which at an axial crease respectively extend out of the round portion towards a free end.