Differential protection relays are widely used for busbar protection. They operate based on the principle of comparing the currents entering and leaving the busbar. A busbar protection is a protection to protect busbars at short-circuits and earth-faults. Index Terms—Breaker failure protection, bus, check zone, cur-renttransformers,differentialbusprotection,dynamicbusreplica, electric power substation, high impedance differential, partial dif-ferential. Your mission is to protect that busbar and one of the customer requirements says that they prefer either a SEL-487B or a SEL-587Z relay for this job. The relay can also be utilized.