Abstract: An insulation system and method are disclosed for insulating formed coils of electrical machines, such as motors and generators. The system includes strand/turn insulation that may include one or more layers of different materials, depending upon the dielectric requirements. A ground wall insulation is applied over the group of turns. The coil may be sized in a slot cell section. Additional insulation layers are provided, including a slot corona suppression insulation that extends just beyond stator slots, a voltage grading layer, and an armor layer. The resulting system is highly adaptable to different machine designs and ratings, and affords superior resistance to degradation.