Abstract:
A coil positioned in the slot of a stator or rotor of an electric machine is formed of a bundle of conductors arranged close together and insulated from each other and from the slot. The conductor insulation consists of corona resistant insulating material running longitudinally of the conductor and surrounding the parts of the conductors facing the main insulation which surrounds the bundle of conductors and also overlies at least those part of the faces of the conductors which face the adjacent conductors which parts are situated nearest the tape facing the main insulation. The tape is formed of a linear unbranched or branched polymer having such thermal stability that the dielectric strength of a film of the polymer 50 microns in thickness, after ageing in air at 155*C for 25,000 hours, is at least 50 percent of the dielectric strength before the ageing and of mica in the form of small flakes.
Abstract:
A coil positioned in the slot of a stator or rotor in an electric machine is formed of a bundle of conductors arranged close together and insulated from each other and from the slot. The conductor insulation consists of a layer of enamel and a tape of corona resistant insulating material running longitudinally of the conductor is adhered to the enamel layer. The tape surrounds the parts of the conductor facing the main insulation which surrounds the bundle of conductors and furthermore overlies at least those parts of the sides of the conductor which face the adjacent conductors which parts are situated nearest the sides facing the main insulation.