What it is and where it fits
The Siemens 3RK1300-1KS01-0AA0 is an EM 300 DS electromechanical direct starter from the SIRIUS family, designed for the ET 200X distributed I/O system. It's a self-contained motor feeder with integrated bimetal overload protection and bus communication via PROFIBUS DP. The unit is rated for AC-3 duty at 5.5 kW at 400 V, with an adjustable setting range of 9 to 12 A. The IP65 enclosure means it's built for direct mounting on the machine or in the field, not inside a central cabinet — it takes the motor feed and control out to the point of use, which saves on wiring and panel space.
What the ratings mean for fit
The 5.5 kW at AC-3 400 V rating tells you this starter handles standard squirrel-cage induction motors up to that power — typical for small conveyors, pumps, or fans in a distributed I/O architecture. The setting range 9...12 A on the bimetal relay means you dial in the motor's full-load current within that window; if your motor draws 10 A FLA, this covers it. The rated short-circuit breaking capacity Icu is 50 A at 400 V, which is the maximum fault current it can safely interrupt — coordinate upstream with a circuit breaker that limits let-through below that. The operating voltage 400...500 V covers 400 V and 480 V line supplies common in industrial plants.
Mounting and wiring
This is a field-mounted unit, not a DIN-rail component for a central panel. It bolts onto the machine frame or a subplate and connects via tab terminals for the main current circuit. The 9-pole motor feeder and 9-pole power connection are pre-wired or terminated with fast-on tabs — no screw terminals to torque, which speeds up installation but means you need the mating connector housings. Dimensions: 270 mm high, 140 mm wide, 134 mm deep. That depth matters if you're fitting it into a shallow enclosure or under a cover; at 134 mm it's not a tight squeeze but it's not a flat pancake either.