The Siemens 3RA2328-8XB30-2AL2 is a SIRIUS reversing contactor assembly in the S0 frame size, rated at 18.5 kW at 400 V AC-3 duty. It ships with one supplied contactor, the 3RT2028-2AL20, and includes two instantaneous auxiliary contacts. Spring-loaded terminals on the main circuit and magnet coil accept 2x (1... 10 mm²) solid or 2x (0.5... 2.5 mm²) stranded wire.
The 18.5 kW rating at 400 V AC-3 means this assembly switches three-phase induction motors up to that load — typical for a 25 hp motor at 460/480 V. The S0 frame size (114 mm high, 90 mm wide, 97 mm deep) fits standard panel layouts; the 6 mm clearance required upwards, downwards, and sideways (0 mm backwards) keeps heat dissipation predictable in a crowded enclosure. The 750 operations per hour maximum at AC-3 and AC-3e limits cycling on high-duty reversing applications like conveyor shuttles or hoist controls.