The term "ring main" is as described. The US term is radial, or loop feeder system.
This is a common application for medium voltage distribution systems. Two breakers, of equal size, supply each end of continuous conductors. This permits isolation switches for disabling portions of the system, and continuity of service is maintained for remainder of loads.
Both feeder breakers must be opened to shut down entire system.
This system also provides two devices to see high current inrush, on start up, instead of one.
