The Siemens 3RA2328-8XB30-2AK6 is a factory-assembled reversing contactor assembly in the SIRIUS family, S0 frame size, rated 18.5 kW at 400 V AC-3 for switching three-phase motor loads in both directions. The assembly includes one supplied contactor (3RT2028-2AK60) per direction of rotation, mechanically interlocked — no external interlock wiring needed.
Rated 18.5 kW at 400 V AC-3 means it handles standard 3-phase induction motors up to that power in reversing duty — conveyors, hoists, winches, and any application needing forward/reverse control. At 480 V the current rating is 34 A, and at 600 V it is 27 A, so the assembly derates with voltage; verify your motor FLA against the curve for your line voltage. Spring-loaded terminals on both the main circuit and the coil accept 2x (1... 10 mm²) solid or 2x (0.5... 2.5 mm²) stranded — no torquing, just strip and push, which speeds wiring in production or field swap. Two instantaneous auxiliary contacts are built in, giving you one N/O and one N/C for status feedback or permissive logic without adding a side-mount block.
Deployment and environmental context
Vibration resistance at AC is 13.5 g / 5 ms and 8.3 g / 10 ms; at DC 15 g / 5 ms and 10 g / 10 ms — suitable for mounting on machinery with moderate shock, like conveyor drives or pump skids. Clearance distances: 6 mm upwards, forwards, downwards, and sideways; 0 mm backwards — plan your DIN-rail spacing so the assembly has room for airflow and wiring access.