The Siemens 3RW5072-6TB04 is a SIRIUS 3RW50 hybrid soft starter with a minimum settable motor current of 90 A and a rated control supply voltage of 200-480 V. The trip class is preset to CLASS 10A / 10E, with a selectable CLASS 20E option per IEC 60947-4-2 — meaning it protects standard and high-inertia starts without nuisance tripping on the same device. ATEX, UKEX, and IECEx approvals are on the nameplate, so it can be wired into Ex-rated motor circuits where the starter must sit outside the hazardous zone but control an in-zone motor.
Fieldbus and control integration
This soft starter ships with PROFIBUS onboard and supports Modbus RTU, Modbus TCP, and EtherNet/IP via optional communication modules. PROFIenergy is available when paired with the PROFINET standard communication module, letting the drive participate in coordinated energy-management pauses on a PROFINET line. The remote reset function cycles the control supply voltage to clear a fault — no separate digital signal needed, which simplifies the wiring back to the PLC. There is no analog output and no torque control on this variant; the soft starter uses a voltage ramp and soft torque profile to manage motor acceleration. The pump ramp down feature is present, so it can decelerate centrifugal loads gradually to avoid water hammer in pump applications.
The 3RW5072-6TB04 is screw-fixed to a vertical mounting surface, rotatable ±90° and tiltable ±22.5° front-to-back. Dimensions are 160 mm wide, 230 mm high, 282 mm deep. Clearance requirements: 100 mm upward, 75 mm downward, 10 mm forward, 5 mm sideways, 0 mm backward — tight enough for a shallow backpanel but plan for the vertical airflow path. Shock resistance is 15 g / 11 ms, with potential contact lifting at 12 g / 11 ms.