The ABB ACS550-U1-04A1-4+B055 is a discontinued three-phase AC drive from the ACS550 series, designed for US installation with NEMA compliance. It operates at 380-480 VAC, 50/60 Hz, delivering 4.1 A current and 1.5 kW power output. The unit features IP54/UL Type 12 and NEMA 1 enclosure ratings.