The Siemens 3RK1300-0GS01-0AA1 is an EM 300 DS electromechanical direct starter designed for the ET 200X distributed I/O system. It's a self-contained motor starting and protection unit that combines a contactor, bimetal overload relay, and short-circuit protection in one IP65-rated enclosure — ready for direct mounting on the machine or in the field without a separate control panel. Rated at 0.18 kW in AC-3 duty at 400 V (the standard motor-starting category per IEC 60947-4-1), it handles the high inrush of squirrel-cage induction motors during starting. The setting range of 0.45 to 0.63 A means the overload relay is factory-set for that window — you adjust the dial to match the motor's full-load current within that band. This part is meant for washdown environments or outdoor installation where a standard panel-mounted starter would need a separate enclosure.
That's roughly a 0.25 HP motor at 400 V three-phase — small pumps, fans, or conveyor drives. The setting range of 0.45 to 0.63 A on the bimetal overload matches the full-load current of a motor in that power band. If your motor draws outside that window, this isn't the right variant. The maximum short-circuit breaking capacity (Icu) is 50 A at 400 V. That's not the motor's running current — it's the fault current the device can safely interrupt. Operating temperature range is 0 to 55 °C. That's typical for a machine-mounted unit but rules out installation in a hot attic or directly next to a furnace without derating. The storage range isn't listed, but the operating limit is the one that governs daily use. PROFIBUS DP onboard means this starter communicates directly with the ET 200X bus — no separate gateway or I/O block needed for start/stop commands and feedback. The brake output (DC 24 V / 3 A) is built in for motors with holding brakes, common in vertical-axis applications.
The part is specified into the ET 200X ecosystem. It drops in with the same bus connector and mounting footprint.
Integration notes
Dimensions are 134 mm deep, 140 mm wide, and 270 mm high. That's a compact footprint for a fully enclosed starter with bus communication and brake output. Mounts directly to the machine frame or a sub-panel via the ET 200X base unit — no DIN rail required. Main current circuit connections use tab terminals (fast-on connectors), not screw clamps. That's typical for the ET 200X system — the motor feeder cable and power connection are pre-wired with mating tabs. Verify your cable ends are terminated with the correct tab receptacles before installation. The 9-pole motor feeder and 9-pole power connection are part of the design. That's a specific pinout for the ET 200X hybrid cable that carries both power and brake control in one jacket. If you're replacing a different starter type, check that the cabling infrastructure matches.