What this order code actually is
The ABB ACS550-U1-06A9-4+P918 sits in the ACS550 series low-horsepower drive frame and is catalogued under Motors & Motor Controls › Drives › Motor Drives, so a buyer cross-referencing the BOM line is looking at a general-purpose industrial drive rather than a dedicated motion controller or soft starter. The +P918 suffix rides on the base ACS550-U1-06A9-4 order code; the description and title fields on record identify the full string as the ACS550 SERIES by ASEA BROWN BOVERI.
Handling and panel fit
At 5.62 kgs the unit is a one-person lift for cabinet mounting, well inside the range a wireman can handle on a panel stub without rigging — relevant for the panel-OEM side of the BOM where the same enclosure often carries an ACH580-01-014A-4 at a near-identical 6.80 kgs.
Series context and a cross-shop note
The same ACS550-U1 series scales up to a 19.96 kg frame at the ACS550-U1-096A-4 order code, which is the next-tier current class in the family and not a panel-swap alternative for the 5.62 kg unit on this BOM line — frame, footprint and current rating class all change. For a kitting lead evaluating a functional second source, the closer weight match in the ABB low-horsepower catalog is the ACH580-01-014A-4 at 6.80 kgs; whether it is a true drop-in for a panel specified around the ACS550-U1-06A9-4+P918 is a wiring and parameter decision, not a weight decision, and is not asserted from this record.