What this SIMATIC direct starter is and what it does
The Siemens SIMATIC 3RK1301-0HB00-0AA2 is a direct motor starter in the SIMATIC motor-starter family, designed for direct-start applications (no reversing). It is rated CLASS 10, meaning it will trip within 10 seconds at a 600% overload — the standard for protecting standard induction motors during start-up. The unit carries a 50 kA short-circuit current rating at 400 V, so it can safely interrupt fault currents up to that level without upstream coordination failure. It integrates PROFINET and PROFIBUS DP protocols, making it a fieldbus-native component for Siemens S7 or third-party controllers.
Key ratings and what they mean for fit
The CLASS 10 trip class governs motor protection: it matches the thermal curve of a standard squirrel-cage induction motor, so nuisance tripping is avoided while locked-rotor conditions are cleared quickly. The 50 kA SCCR at 400 V means this starter can be applied on panels with high available fault current — common in industrial mains — without adding a separate current-limiting fuse or circuit breaker upstream. Supply voltage is 24 V DC nominal, with an operating range of 20.4 to 28.8 V DC, so it holds in during a sagging 24 V bus but drops out cleanly below the undervoltage threshold. The unit is rated for pollution degree 3 at 400 V and degree 2 at 500 V per IEC 60664, meaning it is suitable for industrial environments with conductive dust or light moisture.
Mounting and integration
This starter mounts by plugging onto a terminal module — no separate DIN-rail clip or screw base required. The overall dimensions are 265 mm high, 45 mm wide, and 120 mm deep, so it fits a standard 45 mm-wide slot on a mounting plate. Mounting position can be vertical or horizontal, which gives flexibility in dense cabinets. The main energy infeed uses screw-type terminals; digital I/O is handled via the control module interface, not onboard terminals.