The Siemens 3RK1300-1ES01-0AA1 is an EM 300 DS electromechanical direct starter designed for the ET 200X distributed I/O system. It integrates motor starting, bimetal overload protection, and PROFIBUS DP communication into a single IP65-rated enclosure that mounts directly on the machine or conveyor section, eliminating a separate control panel for small motor groups. Rated for AC-3 duty at 1.5 kW on a 400 V supply, the starter handles the inductive load of standard three-phase squirrel-cage motors up to that power. The setting range of 2.8 to 4.0 A means the bimetal overload relay is field-adjustable to match the motor nameplate FLA within that window — critical for protecting the motor without nuisance tripping. The built-in brake contact (rated DC 24 V / 3 A) controls an externally supplied motor brake, so a single device handles both motor power and brake release. This saves a separate relay and simplifies wiring in applications like vertical conveyors or palletizers where the brake must release before the motor starts.
Operating voltage of 400 to 500 V AC covers the common European 400 V three-phase networks and 480 V North American systems. The DC 24 V control voltage is standard for industrial control circuits, so the starter can be driven directly by a PLC output or a 24 V relay without an intermediate converter.
Mounting and connectivity
The 3RK1300-1ES01-0AA1 measures 140 mm wide, 270 mm high, and 134 mm deep, matching the ET 200X modular footprint. PROFIBUS DP communication is integrated, so the starter reports status and accepts start/stop commands directly over the fieldbus without a separate I/O module. The electromechanical switching contacts provide galvanic isolation between the control circuit and the motor circuit — important for safety and noise immunity.
If your application requires a different setting range or no brake output, Siemens offers other EM 300 DS variants in the same mechanical footprint.