What the code resolves to
The ABB ACS355-03U-05A6-4+J400+K451 is a 3-phase 380-480 V input micro drive from the ACS355 family, sold through the Motor Drives line. The +J400 and +K451 suffixes are factory-fitted option codes carried on the same order string, so the panel-builder receives a single configured part rather than field-installed accessories.
Sizing for the BOM line
The headline rating on this order code is its 3-phase 380-480 V supply class, sized for industrial 400 V line-to-line systems, not single-phase feeds. The 05A6-4 frame sits in the lower-amp bracket of the ACS355 family, intended for fractional-kW motors.
Handling and panel layout
At 1.36 kg the drive is a one-handed install into a DIN-rail or backplate cutout, no lifting tackle required. Keep the cabling short on the line side — long motor pigtails defeat the drive's output filtering and are the usual culprit when an integrator sees a fault code that points at the motor rather than the drive itself.