Abstract: In an electric apparatus, insulating cylinders having different diameters are arranged in a shape of multiple cylinders between the iron core and the low voltage winding, between the low voltage winding and the high voltage winding and on the periphery of the high voltage winding. Spacers are separately arranged between layers of the plurality of insulating cylinders to form a plurality of insulating medium paths. A flow stopping member for stopping the flow of the insulating medium in the insulating medium paths which is made of an insulating material with a low density is arranged at at least one of the upper and lower ends of each of the insulating medium paths.

Abstract: A stationary induction apparatus superior in insulating ability against a surge voltage includes a coil piece on a line end side surrounded by one electrostatic shield insulating layer. The coil piece and electrostatic shield insulating layer, together with another coil piece, are surrounded by another electrostatic shield insulating layer, thus forming a successively nested configuration. Each of the electrostatic shield insulating layers includes an electrical insulating layer of pressboard and first and second conductive layers respectively located on inner and outer surface sides of the electrical insulating layer, The capacitance of each of the electrostatic shield insulating layers is adjusted to control an electrical potential distribution upon application of a surge voltage.

Abstract: In an electric apparatus, insulating cylinders having different diameters are arranged in a shape of multiple cylinders between the iron core and the low voltage winding, between the low voltage winding and the high voltage winding and on the periphery of the high voltage winding. Spacers are separately arranged between layers of the plurality of insulating cylinders to form a plurality of insulating medium paths. A flow stopping member for stopping the flow of the insulating medium in the insulating medium paths which is made of an insulating material with a low density is arranged at at least one of the upper and lower ends of each of the insulating medium paths.

Abstract: An electrically insulating formed channel member is made of a sheet of an electrically insulating material capable of being press formed that is cut to provide radially projecting portions. Thereafter, the sheet is press-formed to form a formed channel member including the channel portion and the projection portions and bent to extend along the inner corner of a rectangular pancake coil with the web located at the inner side of the corner curvature. The sheet material may preferably be a dray paper press board. Ripples may be provided in the sheet material prior to the step of press-forming. The moisture in the sheet material may also be adjusted prior to the step of press-forming.