The ABB ACS550-U1-045A-4+B055 on the U1 frame
The ABB ACS550-U1-045A-4+B055 is the U1 wall-mount AC drive in the ACS550 family, factory-configured with the +B055 option suffix, cataloged as part number ACS550-U1-045A-4+B055. It sits in the Motor Drives class — Drives > Motor Drives under Motors & Motor Controls — which is where the rest of the ACS550 U1-frame siblings also land. The drive weighs 22.68 kgs as listed, so it is a single-person lift with handles but worth a second hand on a mezzanine mount.
Where a U1-frame ABB ACS550 typically lives
ACS550 U1-frame units are the compact wall-mount step in the ACS550 line, normally specified for fan, pump, and conveyor duty where the cabinet footprint has to stay tight and the +B055 option is what the integrator ordered against.
Frame-class siblings worth keeping in the BOM file
The U1 frame covers lower-current siblings such as the ACS550-U1-096A-4 (19.96 kgs), worth listing as an alternate while the 045A is on long lead.