What this part is and what it does
The Siemens SIRIUS 3RK1325-6LS71-3AA0 is a reversing motor starter — a single enclosure that handles forward and reverse direction control for a three-phase motor. It is rated for 5.5 kW at 400 V and 7.5 hp at 460/480 V, so it covers common European and North American motor frames in that power band. The IP65 rating means the housing is dust-tight and protected against low-pressure water jets, so it can mount directly on a machine frame or in a washdown zone without a separate enclosure.
Key ratings and what they mean for fit
The starter offers selectable trip classes 5, 10, 15, and 20. Class 10 is the standard for general-purpose motor starting; Class 20 gives more time for high-inertia loads like fans or centrifuges, while Class 5 protects motors with very short acceleration times. The 24 V DC control supply (20.4 to 28.8 V range, max 31.6 V) is standard for modern PLC-driven panels. Four digital inputs are built in, so you can wire start/stop and direction commands directly without an extra I/O block.
Where it fits in a panel or on a machine
Mounting is by screw fixing, and the unit can be installed vertically, horizontally, or flat — useful when panel space is tight or the machine frame dictates the orientation. Dimensions are 294 mm wide by 215 mm high by 159 mm deep. The main power circuit connects via a HAN Q4/2 plug (ISO 23570), and device addressing uses an M12 plug. It communicates over AS-Interface (no PROFIBUS or PROFINET on this variant), so it fits into an AS-i sensor/actuator bus architecture.
Environmental and mechanical robustness
The starter is rated for operation from -25 to +55 °C, storage and transport from -40 to +70 °C. It withstands shock at 12g for 11 ms and vibration at 7 mm / 2g, so it holds up on a conveyor line or near a press. Pollution degree 3 means it tolerates conductive dust and occasional condensation — typical for industrial floors without climate control.