This is where Ring Main Units (RMUs) play a vital role. RMUs are compact, fully enclosed switchgear designed for medium-voltage power distribution networks. They enhance reliability, improve safety, and support the growing demands of modern smart grids. Improve safety, reliability, connectivity, and efficiency with EcoStruxure™ Grid, our active energy management. This page explains how to design an RMU controller that safely drives actuators, reads reliable position and health feedback, manages isolated power and communications with cybersecurity, and stays dependable for many years in harsh outdoor switchgear environments. According to IEC 62271-200 standards, RMUs serve as load connection points in ring-type distribution.