The Siemens 3RK1300-0BS01-0AA4 is an EM 300 DS electromechanical direct starter designed for the ET 200X distributed I/O system. It integrates motor starting, bimetal overload protection, and PROFIBUS DP communication into a single IP65-rated enclosure — a field-mounted unit that eliminates a separate control panel for small motor branches. Rated for AC-3 duty at 0.06 kW on a 400 V supply, this starter handles the switching of small three-phase induction motors — pumps, fans, conveyors — typical in decentralized automation. The setting range of 0.14 to 0.2 A matches the full-load current of motors in that power band, with the bimetal overload providing Class 10 or 20 trip protection (verify the specific trip class from the device label). The 9-pole motor feeder and 9-pole power connection, with tab terminals for the main circuit, are sized for this current class.
Brake contact and voltage range
A notable feature is the integrated motor brake output (DC 500 V / 1 A), designed for internally supplied brakes on small motors. This saves an external brake rectifier or relay in applications like vertical-axis positioning or holding brakes on conveyors. The operating voltage range of 400 to 500 V AC covers standard 400 V three-phase networks and 480 V industrial supplies common in North American installations. The unit draws 0.14 A at the control voltage (DC), with a full-scale value of 0.2 A.
The part carries no official successor; the EM 300 DS series continues as the active platform for ET 200X direct starters.
This is a field-mount unit designed for direct mounting on machine frames or walls near the motor — not a DIN-rail device. The depth of 134 mm includes the connector overhang; verify clearance for the 9-pole power and motor feeder cables when planning the gland plate layout. The IP65 seal limits ambient to non-condensing conditions.