The 3RW5553-6HA04 is a SIRIUS soft starter from Siemens, rated for a supply of 200 to 480 V. Its trip class is field-selectable among CLASS 10A, 10E (default), 20E, and 30E per IEC 60947-4-2. That means you can match the overload protection curve to the starting characteristic of the motor — CLASS 10A for a standard pump or fan, CLASS 20E or 30E for high-inertia loads like a centrifuge or crusher where the start takes longer. The default 10E setting covers most general-purpose induction motors on a conveyor or compressor. It carries ATEX and IECEx certification, so it is approved for use in potentially explosive atmospheres. CE, UL, and CSA approvals are also on file.
The unit measures 478 mm wide, 764 mm high, and 241 mm deep. It mounts with screw terminals for power and control wiring. Clearance requirements: 100 mm upwards, 75 mm downwards, 10 mm forwards, 0 mm backwards, and 5 mm at the side. That 100 mm upward gap is critical for airflow — the soft starter draws heat out the top, and blocking that space derates the unit above 40 °C ambient, as noted in the operating range of -25 to +60 °C with derating required at 40 °C or above.
Fieldbus and control features
Communication options are built in: PROFIBUS, Modbus RTU, Modbus TCP, and EtherNet/IP are all supported. PROFIenergy is also available when paired with PROFINET standard and High-Feature communication modules. That means the soft starter can be integrated into most common industrial networks without an extra gateway. The analog output can be configured as 4-20 mA (default) or 0-10 V. Control features include DC braking, voltage ramp, pump ramp down, torque control, a breakaway pulse for high-friction starts, combined braking, and an auto-reset function after a fault. The remote reset allows clearing a trip from the control room without walking to the panel. An event list, error logbook, and trace function aid in fault isolation — the trace captures parameter trends leading up to a trip, which saves time when diagnosing intermittent overloads on a critical line.