The Siemens 3RK1300-0HS01-0AA0 is an electromechanical direct starter from the SIRUS EM 300 DS family, designed for the ET 200X distributed I/O system. It's a self-contained motor feeder and starter in one package, rated for AC-3 duty at 0.21 kW on a 400 V supply, with a setting range of 0.55 to 0.8 A. Motor protection is handled by a bimetal overload relay built into the unit, so it trips on thermal overload without needing a separate relay. It communicates over PROFIBUS DP, which means it can be wired into a fieldbus network for remote start/stop and status feedback — no separate control wiring for each motor.
The short-circuit breaking capacity is 50 A at 400 V, so it coordinates with a circuit-breaker upstream for fault isolation.