What arrives when this code lands on the dock
The ABB ACS550-U1-03A3-4+B055 is an AC drive from the ACS550-U1 series, configured with the +B055 option suffix on the base order string. It sits in the Motors & Motor Controls / Drives / Motor Drives class, the standard panel-builder location for general-purpose low-voltage AC drives from ABB. Listed mass is 15.88 kg, which is the figure that drives the enclosure load calc and the one-person lift decision at install — not a selection parameter in itself, but it dictates the mounting hardware and the panel layout around the drive.
Frame-class sibling, and what the gap is actually telling you
The same-series frame sibling ACS550-U1-096A-4 lists at 19.96 kg against this drive's 15.88 kg — a heavier chassis because it carries a larger current frame, not a different family.
Sourcing posture and what to do with the BOM line
The practical move is to quote the exact suffix string ACS550-U1-03A3-4+B055 to the BOM, including the +B055 option, and confirm against the manufacturer's current ordering data sheet before the line freezes — that is how a +B055-configured drive stays matched to the original panel specification.