SIRIUS 3RW52 — fieldbus-ready soft starter for motor starting
The Siemens 3RW5226-3AC04 is a SIRIUS-brand hybrid soft starter rated for a minimum operating current of 32 A across a 200-480 V supply range. It integrates PROFINET, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFIBUS communication, making it a drop-in for multi-protocol control architectures. Trip class is configurable as CLASS 10A (default), 10E, or 20E per IEC 60947-4-2, giving the commissioning engineer flexibility to match the motor thermal model and starting duty cycle without swapping hardware. The unit measures 306 mm high, 185 mm wide, and 203 mm deep, with screw-fixing mounting and a ±90° rotatable mounting surface — the panel layout can tilt ±22.5° front-to-back without losing the vertical orientation spec.
Clearance and ambient derating — panel integration constraints
Minimum clearance around the unit: 100 mm upwards, 75 mm downwards, 10 mm forwards, 0 mm backwards, 5 mm at the sides. These gaps govern the enclosure fill factor — the backwards zero-clearance spec means the backplane can be flush against the mounting plate.
Fieldbus slice and control features — what the integrator needs
PROFINET standard with PROFIenergy support (requires the PROFINET communication module) enables energy management during idle phases — useful for conveyor or pump lines with intermittent duty. Analog output is configurable as 4-20 mA (default) or 0-10 V via the High Feature HMI parameterization, giving the site electrical engineer a direct process-variable signal back to the PLC without a separate transducer. Soft Torque and Pump Ramp Down features are built in — the pump ramp down reduces water hammer on stop, while Soft Torque lowers the starting torque for belt-driven loads. Auto-reset and remote reset (by cycling the control supply voltage) are supported, with an error logbook available only with special accessories — the commissioning engineer should verify the accessory kit is ordered if fault logging is needed.
Certification and compliance — documentation for the MRO file
Shock resistance is rated 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms — relevant for marine or mobile equipment installations where vibration is a concern. Minimum load is 15% relative to the smallest settable Ie — the MRO planner should confirm the motor FLA stays above this threshold to avoid nuisance tripping on lightly loaded motors.