ABB 289B456A21 is an overcurrent protection relay from the COM-5 family, designed for fast current-based tripping in protection schemes. The part is cataloged by ABB as 289B456A21 and is listed in nuclear-qualified component catalogs as an ABB relay for overcurrent protection. The designation indicates 10-40 IIT unit and 16-32 ITH unit with the BG enclosure variant, reflecting its modular input/current and thermal handling options. This relay is intended for protection schemes that monitor current and trip on overcurrent conditions, suitable for power distribution panels and other safety-critical electrical installations where reliable protection is required.
