What it is and where it fits
The Siemens 3RK1300-1KS01-1AA3 is an electromechanical reversing starter from the SIRIUS EM 300 RS family, designed for the ET 200X distributed I/O system. It's a self-contained motor-reversing unit with bimetal overload protection, rated for 5.5 kW at AC-3 duty on a 400 V supply, with a setting range of 9 to 12 A. The IP65 enclosure means it's built for direct-on-machine mounting in washdown or dusty environments — no separate panel box needed.
Key ratings and what they mean
The 5.5 kW AC-3 rating at 400 V is the motor-switching capability for squirrel-cage induction motors — that's the real-world figure for sizing, not a resistive-heater number. The 9 to 12 A bimetal overload range sets the motor FLA window; you dial it to match the nameplate. Operating voltage is 400 to 500 V AC, so it handles 400 V line-to-line and 480 V common in North American 480Y/277 systems. The short-circuit breaking capacity is 50 A at 400 V, meaning the integrated circuit-breaker-style protection can clear a fault up to that level without upstream damage.
Communications and brake output
This starter includes a PROFIBUS DP interface for direct bus communication to a PLC — no separate gateway module. It also has a motor brake output (24 V DC internally supplied) for holding brakes on vertical-axis drives. The main current circuit connects via tab terminals, typical for the ET 200X plug-in system. Ambient operating range is 0 to 55 °C.