The ABB ACS550-U1-04A1-4+B055 is an AC drive in the Motor Drives class, listed at 5.44 kgs. Voltage class, current rating, and frame size are not on the storefront line and must be read from the official ABB datasheet before this part is written into a motor circuit.
What the listed spec actually tells you
Only one numeric spec travels with this order code: 5.44 kgs of unit weight. On a low-horsepower ACS550-U1 frame that is a single-handed lift onto a panel backplate or DIN mounting plate, so handling drives the rigging decision rather than panel reinforcement. Voltage class, current rating, frame size, and the meaning of the +B055 option suffix are not stated on the storefront line and must be read off the ABB ACS550-U1 datasheet before this part is written into a motor circuit.
Where this drive class sits in the panel
The ACS550-U1 family is ABB's general-purpose industrial AC drive line, the kind of unit wired between a three-phase supply and a motor contactor or direct-on-line motor in a control panel. Without voltage, current, and power figures on the storefront line, the procurement move is to pin down the motor it will feed, confirm the ACS550-U1 frame that matches it on the datasheet, and only then commit ACS550-U1-04A1-4+B055 to the BOM with its full configured option list.
Sourcing posture
No official lifecycle status, phase-out notice, or successor order code is on file for ACS550-U1-04A1-4+B055, so production state is not asserted from the storefront line. The clean move is to submit an RFQ with the full configured string, including the +B055 option, and have it quoted to order. Compliance paperwork is not listed and has to come from ABB with the quote.