What the order code tells you
The ABB ACS550-U1-072A-4+B055+K466 sits in the ACS550 series as a Motor Drives class unit, part number ACS550-U1-072A-4+B055+K466, with the +B055 and +K466 suffix options applied to the base 072A frame code. It is listed at 31.75 kg, the figure that drives panel-cut planning and the two-person lift call-out rather than any electrical fit decision.
Where this class gets used
Motor Drives in this catalog tier are specified to vary AC induction motor speed and torque on industrial machinery — pumps, fans, conveyors, mixers — where the drive sits between the supply and the motor and handles the soft-start, ramp, and protection profile.
Same-frame alternates to weigh
The ACS550-U1-072A-4+B055+L512 is the closest same-frame alternate at 34.02 kg, with the +L512 suffix swap for +K466 as the engineering check before any drop-in call. The ACS550-U1-059A-4+B055 is the next-down current frame in the same +B055 option family at 36.29 kg, and the ACS550-U1-096A-4 is the next-up current frame without the +B055 suffix at 19.96 kg — neither is a like-for-like swap for this order code, so treat them as frame neighbours rather than substitutes.