What the line item is
The ABB ACS800-U4-0140-5+J400+P901 is an AC cabinet-format drive on the Motor Drives line, ordered as a configured build with the +J400 and +P901 option codes appended to the base ACS800-U4 frame size.
Second-source framing per the specification
The closest sibling on the record is the ACS880-01-156A-5, but the two are not the same generation — the ACS800-U4 is the legacy cabinet drive and the ACS880-01 is the current-generation wall-mount drive, so specifying one as a substitute for the other without re-checking the panel cut-out, the fieldbus option slot and the motor-side parameter set is not defensible against a tender challenge. The ACS580-01-180A-4 and the ACS550-U1-157A-4 sit in the same Motor Drives class but in a different mechanical and firmware generation, so they are alternate MPNs in the line, not certified replacements for this configured ACS800-U4 build.
Sourcing posture
Specify this MPN exactly on the RFQ; the ACS800-U4 generation is no longer the current ABB drive platform, so quote the configured unit to order.