What the order code pins down
The ABB ACS550-U1-046A-2+B055+L512 sits inside the ACS550 low-voltage drive family, catalogued as a Motor Drive under Drives / Motor Drives, and the +B055 / +L512 suffix block is part of the order code string a buyer quotes on the PO line — not a cosmetic extension.
What 9.07 kgs does to the install
Listed at 9.07 kgs, the unit is a one-person lift on a panel backplate, and the cabinet has to carry that mass plus the drive's cooling clearances — plan the backplate reinforcement and the lift path before the crate lands in the electrical room.
Frame-class neighbours, not cross-references
ACH550-UH-023A-4 carries an HVAC-oriented firmware profile at 11.34 kgs and is treated as a separate product line, so parameter sets and fieldbus mappings do not port across without a re-commission. The newer ACH580-01-014A-4 platform at 6.80 kgs is a generation shift, not a verified substitute — the mechanical footprint and the control block architecture move with it, so a swap is a re-engineering task rather than a panel drop-in.