The Siemens 3RW5077-2AB05 is a SIRIUS-series soft starter rated for a minimum set current of 240 A across a 200 to 600 V supply range, making it a fit for medium-horsepower induction motors — think pumps, fans, compressors, and conveyors in the 100–150 kW ballpark on 400 V three-phase. ATEX and IECEx certified per IEC 60947-4-2. Screw fixing; 160 mm wide, 230 mm high, 282 mm deep.
The 240 A minimum rating is the smallest motor current the starter can be set to — it is not a maximum. The actual maximum motor FLA it can handle depends on the overload relay selected and the ambient derating curve. Trip Class 10A / 10E (preset) / 20E per IEC 60947-4-2 means the starter can be configured for normal (Class 10) or extended (Class 20) acceleration profiles. Class 10A protects standard squirrel-cage motors during start; Class 20E allows longer ramp times for high-inertia loads like centrifuges. The analog output defaults to 4-20 mA and can be parameterized to 0-10 V via the High Feature HMI — useful for feeding motor current to a PLC or SCADA without an external transducer.
Communication and control options
This soft starter supports PROFINET standard, PROFIBUS, EtherNet/IP, Modbus RTU, and Modbus TCP natively — no separate communication module required for these protocols. It also supports PROFIenergy in conjunction with the PROFINET standard communication module, allowing energy-saving shutdown of the motor during idle periods in automated production lines. Remote reset is achieved by cycling the 24 V DC control supply voltage — no separate reset signal needed.