Direct starter with PROFINET and PROFIBUS — 50 kA SCCR, trip-class flexibility
The Siemens SIMATIC 3RK1301-0BB10-0AB4 is a direct starter motor starter that integrates PROFINET and PROFIBUS DP protocols natively — no gateway module needed between the controller and the motor branch. It's designed for 24 V DC control supply (20.4–28.8 V range) and carries a 50 kA rated short-circuit current at 400 V, meaning it can safely interrupt fault currents up to that level without cascading upstream protection. Trip class is selectable among CLASS 5, 10, 15, and 20, letting you match the overload release to the motor's thermal time constant — CLASS 5 for submersible pumps that need fast lock-rotor protection, CLASS 20 for high-inertia loads like centrifuges. Two digital inputs are on board (2 byte input image, 2 byte output image), and the unit mounts vertically or horizontally, plugging onto a terminal module for quick replacement without pulling wiring.
Integration — panel fit and environmental limits
Dimensions: 290 mm high, 65 mm wide, 150 mm deep. That 65 mm width is a single 4 HP (or 4 TE) DIN-rail footprint — it occupies one slot in a standard 19-inch subrack or on a 35 mm DIN rail. Operating temperature range is 0–60 °C, storage and transport -40–+70 °C. Shock resistance is 5g / 11 ms, vibration 2g — this holds takt time on a body-shop weld line where one minute of downtime costs thousands. Pollution degree is rated 3 at 400 V and 2 at 500 V per IEC 60664 / IEC 61131, so the device is suitable for industrial environments with conductive dust or occasional condensation — typical for automotive assembly or material-handling panels. The fastening method is pluggable on a terminal module, which means the power and bus wiring stay in the panel when the starter is swapped — a field-service tech can pull the unit and replace it in under a minute without re-terminating.