What this soft starter does for the motor circuit
The Siemens SIRIUS 3RW5243-6AC14 is a hybrid switching device — a soft starter — sized for a minimum motor current of 90 A at a rated voltage of 200 to 480 V. Its default Trip Class is CLASS 10A per IEC 60947-4-2, meaning it protects standard squirrel-cage induction motors during start-up by limiting inrush current and allowing a controlled ramp. The trip class is field-configurable to 10E or 20E for higher-inertia loads like centrifuges or long conveyors where a longer acceleration time is needed without nuisance tripping. The unit delivers Soft Torque and Pump Ramp Down features, which reduce mechanical stress on the load and prevent water hammer in pump applications. It also supports a remote reset by cycling the control supply voltage, useful for unattended installations.
Fieldbus and control integration
This soft starter supports PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET, making it compatible with most common industrial networks. PROFIenergy is available when used with the PROFINET communication module, allowing energy-saving shutdowns during production pauses. An analog output is provided — 4 to 20 mA by default, or 0 to 10 V when parameterized via the High Feature HMI. Mounting is by screw fixing on a vertical surface, rotatable ±90° and tiltable ±22.5° front-to-back. The envelope is 203 mm deep, 210 mm wide, and 393 mm high, with clearance requirements: 100 mm above, 75 mm below, 10 mm forward, and 5 mm at the sides.