The ring main unit (RMU) is a crucial piece of equipment used in switching stations and substations. The RMU effectively removes all transient voltages on distribution lines, along with providing a short-circuit current path around tripping mechanisms. Their primary goal is to allow power flow at all times through closed switches and protect downstream equipment from dangerous voltage transients, faults, and any other unforeseen power disturbances. In recent years, new technologies have emerged that could change how these units operate while reducing their overall size and complexity. This has prompted Schneider Electric—one of the world’s leading manufacturers of power control technology—to implement several updates to its existing designs and introduce newer generation devices. The ring main unit (RMU) are used in large commercial buildings, industrial plants, utilities and other similar facilities