The Siemens 3RK1300-0FS01-1AA3 is an EM 300 RS electromechanical reversing starter designed for the ET 200X distributed I/O system. It integrates motor protection via a bimetal overload relay, PROFIBUS DP communication, and a motor brake output into a single IP65-rated enclosure. Rated for AC-3 duty at 0.12 kW on a 400 V supply, the unit's setting range spans 0.35 to 0.5 A, making it suitable for small reversing motor applications such as conveyor drives or valve actuators in washdown environments.
Integration and mounting
Housed in a 140 x 270 x 134 mm (W x H x D) enclosure rated IP65, this starter mounts directly on machine frames or in field junction boxes — no separate control cabinet required. The IP65 rating means the electronics withstand hose-directed water and dust ingress, so it can sit right on the motor frame in a food or beverage line. Main circuit connections use tab terminals; the unit communicates over PROFIBUS DP and includes a dedicated motor brake output for internally supplied brakes. The 9-pole motor feeder and 9-pole power connection are pre-configured for the ET 200X backplane.
Electrical ratings and protection
The bimetal motor protection covers the 0.35 to 0.5 A range. Short-circuit protection is provided by integrated circuit-breakers with a maximum breaking capacity of 50 A at 400 V (Icu). The operating voltage range is 400 to 500 V DC, and the unit operates in ambient temperatures from 0 to 55 °C. Equipment marking per DIN EN 61346-2 is Q (power switching device). The electromechanical switching contacts are rated for AC-3 motor switching duty at 0.12 kW / 400 V.