What this part is and what it does
The Siemens 3RK1300-1BS01-0AA1 is an electromechanical direct starter from the SIRIUS EM 300 DS family, designed for the ET 200X distributed I/O system. It combines a contactor and a bimetal overload relay in one enclosure, rated for AC-3 motor duty at 0.75 kW at 400 V. The setting range is 1.4 to 2.0 A, with a fixed full-scale value of 2 A.
Key ratings and what they mean for fit
The 0.75 kW AC-3 rating at 400 V tells you this starter is sized for small three-phase induction motors — think fractional-horsepower pumps, fans, or conveyor drives. The 1.4 to 2.0 A setting range matches the full-load current of a 0.75 kW motor at 400 V; you dial the bimetal relay to the motor nameplate FLA. The IP65 enclosure means the starter is dust-tight and protected against water jets, so it can mount directly on a machine frame or in a washdown zone without a separate enclosure. Operating voltage is 400 to 500 V AC, three-phase, covering standard European 400 V and 480 V North American supplies. Ambient temperature range is 0 to 55 °C during operation — fine for most indoor industrial environments, but watch the upper end if the starter is inside a hot cabinet. The maximum short-circuit breaking capacity (Icu) at 400 V is 50 A, meaning the integrated short-circuit protection (circuit-breaker type) can safely interrupt a fault up to that level.
Built-in brake output and bus communication
This starter includes a motor brake output rated DC 24 V / 3 A, designed for externally supplied brakes on motors with holding brakes. The brake contact is integrated, so you don't need a separate relay for the brake coil. PROFIBUS DP communication is built in — the starter talks directly to a PLC via the ET 200X backplane, giving you remote start/stop, fault feedback, and current monitoring without hardwiring each motor circuit back to a central cabinet.
Dimensions and mounting
The enclosure measures 134 mm deep, 140 mm wide, and 270 mm high. It's a standalone block designed for direct mounting on a machine or in a small junction box — not a DIN-rail snap-on unit. Main current connections use tab terminals (fast-on type), which are common for distributed starter blocks in the ET 200X ecosystem. The 9-pole motor feeder and 9-pole power connection are pre-configured for plug-in cabling.