EasyDry®

Through continuous investments in research and development, Hitachi Energy became the inventor of the paperless resin-impregnated synthetic (RIS) bushing technology. In our flagship RIS line, EasyDry®, we have substituted traditional paper insulation with homogeneous synthetic material, resulting in superior product properties and lifetime.

Hitachi Energy’s paperless RIS bushings are made of a synthetic nonwoven material wound around a conductor with aluminum foil inserts for electrical stress control. The core is then vacuum-impregnated with epoxy resin and cured, giving a partial discharge-free dry bushing.

This paperless bushing technology has advanced insulation performance due to its non-hygroscopic insulation, which is not sensitive to moisture ingress and absorption. In addition, RIS bushings will have a superior effect on the power factor (dielectric losses) and intrinsic aging behavior, leading to an extended product lifetime.