What this reversing starter is and where it fits
The Siemens 3RK1300-1GS01-1AA3 is an electromechanical reversing starter from the SIRIUS EM 300 RS family, designed for the ET 200X distributed I/O system. It combines a reversing contactor, bimetal overload relay, and PROFIBUS DP communication in a single IP65 enclosure — meaning it mounts directly on the machine or conveyor section, not in a central panel. Rated 2.2 kW at AC-3 duty at 400 V, with a setting range of 4.5 to 6.3 A, this starter is sized for small three-phase motors — pumps, fans, roller drives — where reversing is needed and the motor protection must be local. The bimetal overload provides thermal protection matched to the motor's heating curve. Operating voltage is 400 to 500 V AC, and the unit carries a 50 A short-circuit breaking capacity (Icu) at 400 V — enough to clear a fault before upstream devices trip, provided the branch circuit is coordinated per the manufacturer's selectivity tables.
Fieldbus and brake integration
PROFIBUS DP is onboard — no external gateway needed. The starter communicates motor status, fault flags, and current draw directly to the PLC over the bus. This saves a remote I/O drop and simplifies wiring on distributed architectures like ET 200X. A motor brake output is integrated, controlled by the same logic that drives the contactor coils. For applications with holding brakes (vertical conveyors, gantries), this eliminates a separate brake rectifier and interposing relay. The brake supply is internal, AC 400 V, fed through the 9-pole motor feeder.
Enclosure, mounting, and wiring
IP65 rating means the housing is dust-tight and protected against low-pressure water jets — suitable for washdown areas, outdoor installations, and food-processing zones where hose-down cleaning is routine. The enclosure is self-contained; no additional cabinet is required. Dimensions are 140 mm wide, 270 mm high, and 134 mm deep. Main circuit connections use tab terminals (fast-on type), typical for distributed starters where quick disconnect is valued. The 9-pole motor feeder and 9-pole power connection are part of the assembly. Ambient operating temperature range is 0 to 55 °C — standard for industrial enclosures without forced cooling. Below 0 °C the bimetal trip characteristics shift; the starter should not be commissioned in freezing conditions.