Siemens 3RK1300-0ES01-1AA3 — the reversing starter for ET 200X
This is an electromechanical reversing starter from the SIRIUS EM 300 RS family, designed to mount directly into an ET 200X distributed I/O system. It handles motor reversing and overload protection in one package — bimetal motor protection, a 0.28 to 0.4 A setting range, and a rated motor power of 0.1 kW at 400 V in AC-3 duty. The IP65 enclosure means it lives out on the machine, not in a sealed cabinet, so it sees washdown, dust, and whatever else the line throws at it.
What the key ratings mean for fit
The 0.28-0.4 A setting range (initial value 0.28 A, full-scale 0.4 A) is the bimetal overload trip window — you set it to the motor nameplate FLA. At 0.1 kW / 400 V AC-3, this is sized for small reversing drives: conveyor shuttles, gate actuators, or positioning tables. The 50 A short-circuit breaking capacity at 400 V means the integrated circuit-breaker-style protection clears a fault without upstream devices having to trip — keeps the rest of the line running. That 50 A figure is the Icu, the ultimate breaking capacity under fault conditions. The integrated motor brake output is the detail that matters if you're stopping a load that holds position — a vertical axis or a conveyor that back-drives. It switches the brake coil internally, so you don't need a separate brake contactor or a timing relay. That saves a DIN-rail slot and a wiring step.
Where this class of part is used
Reversing starters like this one go into motor control circuits where the load needs to run in both directions — think conveyor reversals, door open/close, or any bidirectional actuator. The ET 200X form factor means it plugs into a distributed I/O rail out on the machine, communicating over PROFIBUS DP. The IP65 rating lets it sit in a washdown zone or a dusty environment without an extra enclosure. Tab terminals on the main circuit match the standard ET 200X power connector — no special crimp tool needed beyond what you already carry.