The Siemens 3RK1300-0CS01-1AA3 is an EM 300 RS electromechanical reversing starter designed for the ET 200X distributed I/O system. The setting range is 0.18 to 0.25 A, with an AC-3 motor rating of 0.06 kW at 400 V. That 0.06 kW figure is the actual motor power it can switch under AC-3 duty (starting and stopping a squirrel-cage induction motor), not a resistive load rating — so it fits small motors like those on indexing tables, small conveyors, or valve actuators. The bimetal overload relay provides Class 10 motor protection, and the unit includes a brake contact for internally supplied DC brakes on the motor. Communication is via PROFIBUS DP, allowing the starter to be addressed and monitored directly from a PLC without hardwired control signals — the bus carries start/stop commands, direction, and fault feedback.
Integration Notes
The starter mounts to the ET 200X backplane via a 9-pole motor feeder and 9-pole power connection — it is not a standalone DIN-rail component but a module in the Siemens distributed I/O system. Dimensions are 140 mm wide, 270 mm high, and 134 mm deep, so it occupies a defined slot in the ET 200X assembly. The main circuit connections use tab terminals, which mate with the backplane connector rather than requiring field wiring to the module itself. The PROFIBUS DP interface uses the standard ET 200X bus connector, and the brake output is for internally supplied DC brakes — note that the brake supply voltage matches the motor voltage (400-500 V AC), not a separate 24 V DC brake supply.