What this part is and what it does
The Siemens 3RK1300-1ES01-0AA4 is an EM 300 DS electromechanical direct starter from the SIRIUS family, designed for distributed motor control in ET 200X environments. It integrates a contactor, bimetal overload relay, and PROFIBUS DP communication in a single IP65-rated enclosure — meaning it can be mounted directly on the machine or conveyor section, not just inside a central panel. The setting range of 2.8...4.0 A covers small motors up to 1.5 kW at 400 V in AC-3 duty (squirrel-cage induction motors), and the integrated motor brake output (DC 500 V/1 A) handles internally supplied brakes without an external relay.
Key ratings and what they mean for fit
The AC-3 rating of 1.5 kW at 400 V is the headline motor-switching capacity — this part is sized for small three-phase induction motors, not resistive loads or larger drives. The short-circuit breaking capacity (Icu) is 50 A at 400 V, so it coordinates with a 50 A upstream circuit breaker; if your fault current exceeds that, you need a current-limiting device upstream. The operating voltage range is 400...500 V AC, which covers standard 400 V and 480 V line supplies. The IP65 protection class means the unit is dust-tight and protected against water jets — suitable for washdown areas or outdoor installation, but the tab terminals for the main circuit (not screw terminals) require matching tab connectors.
Deployment context
The unit is designed for distributed installation on the ET 200X remote I/O platform — it mounts directly on the machine frame or conveyor section, not on a DIN rail in a central cabinet. The 9-pole motor feeder and 9-pole power connection (tab terminals) are pre-wired for quick connectorization. The PROFIBUS DP interface allows the starter to be controlled and monitored from the PLC without separate control wiring. Ambient temperature range is 0...55 °C during operation, so it can live in a non-conditioned production area.