The Siemens 3RK1300-0GS01-0AA4 is an EM 300 DS electromechanical direct starter from the SIRIUS family, designed for the ET 200X distributed I/O system. It's a self-contained motor starting and protection unit with a bimetal overload relay, rated for AC-3 duty at 0.18 kW on a 400 V supply. The setting range is 0.45 to 0.63 A, so it's sized for small three-phase motors — fractional-horsepower pumps, fans, or conveyor drives in a distributed architecture. It communicates over PROFIBUS DP, which lets the PLC read motor current status, trip conditions, and control the starter directly over the fieldbus. No AS-Interface onboard — this is a PROFIBUS-native slice.
The 0.18 kW rating at AC-3 (400 V) is the motor-switching capacity — it's the maximum induction motor load this starter can handle under starting and stopping duty. The 0.45 to 0.63 A setting range is the overload relay's adjustable pickup window; you set it to match the motor's full-load current within that band. The maximum short-circuit breaking capacity (Icu) is 50 A at 400 V. That's the fault current this device can safely interrupt — it's coordinated with upstream circuit-breakers (as noted in the design) rather than fuses. For a 0.18 kW motor, a 50 A fault rating is ample; the upstream breaker will clear before the starter sees a higher let-through. Operating voltage is 400 to 500 V, covering standard 400 V three-phase networks across Europe and 480 V North American systems. The control voltage is DC — the integrated brake output (rated DC 500 V / 1 A) handles internally supplied motor brakes, common on small servo or holding-brake motors. Ambient operating temperature is 0 to 55 °C — it's rated for the inside of a non-conditioned enclosure or machine frame, not for a freezer or furnace zone.
This is a distributed starter — it mounts on the ET 200X motor starter interface, not on a DIN rail in a central panel. The IP65 rating lets it live on the machine, close to the motor, saving cabinet space and reducing power cabling runs. The PROFIBUS DP connection carries control and diagnostics back to the PLC over a single bus cable. The integrated brake output (DC 500 V / 1 A) means you don't need a separate brake rectifier or contactor for motors with DC holding brakes — the starter switches both motor power and brake coil from one unit. The 9-pole motor feeder and 9-pole power connection handle the combined wiring.