Ring main units RMU

Ring-main units are consisting of switches on both sides of the T-off, one to open the ring and another at the connection to the distribution transformer using one of the following:
Switch and a fuse separately
combination Switch-fuse
Circuit breakers

A three-phase electrical ring main unit comprising a lower chamber module having a wall structure formed from insulating resin material; three input contacts , one for each phase, mounted within the lower chamber; three lower switching contacts , each mounted within the lower chamber for movement between different switching positions; insulating closure means closing the top of the lower chamber; three output contacts , one for each phase, carried by and exposed on a lower face of the closure means...