Part identity and what the code tells you
The ACS800-U31-0040-5 is an AC Drive catalogued under Motors & Motor Controls, Drives, Motor Drives (ASEA BROWN BOVERI). The U31 suffix marks the wall-mount IP21 form factor of the ACS800-U31 series.
Handling and mounting footprint
Listed mass is 29.48 kgs, a single-installer lift onto a reinforced backplate rather than a DIN-rail snap-on. Plan cabinet handling around a 29.48 kg chassis with cooling clearance top and bottom per the U31 frame.
Where the U31 sits in the migration path
The ACS800-U31 is the legacy predecessor to ABB's ACS880-01 wall-mount line, which is the family most new panels are specified against today. Buyers cross-shopping this code against the ACS880-01-040A-5 (18.14 kgs) or ACS880-01-065A-5 (23.13 kgs) are looking at the modern replacement frame; the U31 cannot be specified as a drop-in for an ACS880-01 panel because the mechanical footprint, control board layout and firmware toolchain differ between the two generations.
RFQ and next step
If the ACS800-U31-0040-5 is on the BOM as a like-for-like spare for an installed ACS800 cabinet, send the part number and quantity for a quoted lead; if it is being considered as a substitute for an ACS880-01-040A-5 or ACS880-01-065A-5 panel position, the engineering review has to come before the RFQ because the two frames are not mechanically interchangeable.