The Siemens 3RK1325-6KS71-2AA0 is a SIRIUS direct motor starter with integrated AS-Interface communication, rated for 0.75 kW at 400 V and 750 W at 500 V. It is a fully enclosed unit (IP65) designed for distributed motor control in harsh environments — washdown zones, conveyors, or outdoor installations where a central panel isn't practical. The 24 VDC control supply powers the onboard logic and the AS-Interface bus, with a permissible range of 20.4 to 28.8 V DC. The trip class is selectable among CLASS 5, 10, 15, or 20, which means you can match the overload protection to the motor's thermal time constant — CLASS 10 for standard induction motors, CLASS 20 for high-inertia loads like fans or crushers that take longer to start.
Mounting, environment, and integration
This starter mounts via screw fixing (not DIN rail) and can be installed vertically, horizontally, or flat — the recommended orientation is horizontal. Dimensions are 294 mm wide by 215 mm high by 159 mm deep, so it occupies a substantial footprint; plan your gland plate and cable entry accordingly. Vibration resistance is 7 mm / 2g, shock resistance 12g for 11 ms — robust enough for most industrial machinery, but not for high-impact presses or hammer mills without additional damping.
The unit carries 4 digital inputs and 1 digital output, addressable via the AS-Interface protocol through an M12 plug. This makes it a self-contained node on an AS-i network — no separate I/O block needed for local sensors or actuators. The main power connection uses a HAN Q4/2 plug per ISO 23570. There is no PROFIBUS or PROFINET onboard; if your plant runs on those fieldbuses, you'll need a gateway or a different variant.