What this soft starter does on the line
The Siemens SIRIUS 3RW5243-2AC15 is a hybrid switching soft starter for three-phase induction motors, sized for a minimum motor current of 90 A and a control supply voltage range of 200 to 600 V. Its default trip class is CLASS 10A per IEC 60947-4-2, configurable to 10E or 20E — meaning you can match the overload protection curve to the motor's starting profile, from fast starts (10A) to extended acceleration (20E). The unit speaks PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP natively — no gateway hack required to fold it into a multi-vendor BMS or PLC network.
Fieldbus integration and control options
With PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP on board, this soft starter eliminates the need for a separate communication module in most panel builds. The analog output defaults to 4-20 mA but can be parameterized to 0-10 V using the High Feature HMI — useful when feeding a legacy analog input card. PROFIenergy support is available in conjunction with the PROFINET standard communication module, enabling energy management profiles during idle periods.
Screw fixing to a vertical mounting surface; the unit is rotatable ±90° and tiltable ±22.5° front-to-back, giving panel builders flexibility in tight enclosures. Dimensions are 203 mm deep, 210 mm wide, and 393 mm high — plan for this footprint when laying out the gland plate and busbar runs. Clearance requirements: 100 mm above, 75 mm below, 10 mm forward, 5 mm to the side, and 0 mm backward — the back can sit flush against the panel wall.
Carries UL, CSA, and CE marking, covering North American and European regulatory jurisdictions without additional certification work. Shock resistance rated at 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms — relevant for applications on vibrating machinery or mobile equipment.