Secure, dependable and scalable bus differential protection system for LV, HV and EHV busbars. The B90, a member of the UR Family, features integrated protection and breaker failure for re-configurable MV, HV, EHV multi-section busbars with up to 24 feeders. Use one or more B90s together to build a flexible protection system that can be engineered to meet specific application requirements. The B90 performs fast and secure low-impedance bus protection with a sub-cycle tripping time of 0.75 cycles and 04 differential zones per phase.