The Siemens SIMATIC 3RK1301-0CB00-1AA2 is a reversing motor starter — meaning it handles both forward and reverse starting of a three-phase motor from a single unit, without needing an external interlock contactor pair. The supply is 24 V DC (20.4 to 28.8 V range), and it communicates over both PROFINET and PROFIBUS DP, giving you fieldbus connectivity without an extra gateway module.
The pollution degree rating of 3 at 400 V and 2 at 500 V per IEC 60664 / IEC 61131 means the creepage distances are designed for industrial environments with conductive dust or condensation; at 500 V the pollution degree drops to 2, so cleaner air is assumed. The 5g / 11 ms shock resistance and 2g vibration resistance make it suitable for machine-mounted applications near rotating equipment or conveyors.
The starter fastens by plugging onto a terminal module — it doesn't bolt to a DIN rail directly; the terminal module takes the rail. That means the replacement swap is a pull-and-plug without disturbing the power wiring, as long as the base module stays on the rail. The main energy infeed uses screw-type terminals, which wire up clean with ring or fork lugs — no spring clips to torque-guess. Dimensions are 120 mm deep, 90 mm wide, 265 mm tall. Mounting position is vertical or horizontal, so you can lay it sideways in a shallow enclosure if the cable bend radius allows.