What the order code buys you
The ABB ACS550-U1-045A-4 is a 45 A, 22 kW AC drive built around a 380-480 VAC three-phase supply at 50/60 Hz. At 16.78 kg the unit is a one-person lift onto a vertical surface, but the thermal mass is the real figure that matters: 22 kW of inverter loss and cooling airflow want genuine clearance top and bottom, so do not crowd it between a heat-producing contactor above and a cable trunk below.
Rating so-what for the panel builder
The 45 A output and 22 kW rating at 380-480 VAC come from a single spec row; size upstream branch protection and motor cabling off the 45 A figure for that voltage class.