What it is and how it gets specified
The ABB ACS550-U1-059A-4 is a 3-phase general purpose drive rated for 480 V AC supplies, with 380-480 V AC input tolerance across the listed band. It carries a dual-duty horsepower rating — 30 HP heavy duty and 40 HP normal duty — so the same order code covers two different load-profile applications depending on which current ceiling the integrator targets. NEMA 1 enclosure, R4 frame, wall-mount package at roughly 27.1 in H x 8 in W x 10.3 in D, sized for the cabinet real estate typical of industrial control rooms.
Reading the current ratings
Normal duty output is 59 A and heavy duty is 44 A on this order code, and that pair is what actually drives panel sizing, breaker coordination, and cable selection — not the headline HP number. If the motor is a constant-torque load (conveyors, mixers, positive-displacement pumps), the 44 A heavy-duty figure is the one the BOM line is built around; 59 A is the variable-torque ceiling for fans and centrifugal pumps. Same frame class, same supply range, just a different thermal envelope in the IGBT stage and that is the procurement-relevant gap.
Panel and feeder fit
3-phase supply at 480 V AC, with a 380-480 V AC input band, drops onto the typical US industrial feeder without a step-down transformer. NEMA 1 and the R4 wall-mount envelope mean it lives on a backpan in a clean cabinet rather than on the machine skin, so plan for the 27.1 x 8 x 10.3 in footprint plus cable bend room and clearance above the drive for heatsink airflow. The R4 frame is shared with adjacent ACS550 ratings, which simplifies spare stocking if the plant standardizes on this family.