The Siemens 3RW5553-2HA06 is a SIRIUS soft starter with a configurable trip class — CLASS 10A / 10E (default) / 20E / 30E per IEC 60947-4-2 — which means you match the overload protection curve to the motor's starting profile. A CLASS 10A setting clears a start within 10 seconds at 7.2x rated current, suited for normal-load starts like pumps and fans; CLASS 20E or 30E buys you longer acceleration time for high-inertia loads such as centrifuges or crushers. The default 10E gives a 10-second window with electronic (not bimetal) characteristics, so the starter tracks actual motor heating rather than a thermal replica. Rated 200... 690 V, it covers standard low-voltage three-phase systems. The analog output is configurable 4... 20 mA (default) or 0... 10 V. ATEX and IECEx certification (both Yes) means this unit is approved for installation in explosive atmospheres.
Fieldbus and integration
This soft starter speaks Modbus RTU, Modbus TCP, EtherNet/IP, and PROFIBUS natively — no separate gateway module needed. That means it drops into a Rockwell, Siemens, or Schneider control architecture on the same wire as the rest of the motor control center. PROFIenergy support (in connection with PROFINET High-Feature communication modules) lets a PROFINET controller put the starter into energy-saving standby between production cycles. The unit is 478 mm wide, 764 mm high, 241 mm deep — a substantial footprint that typically requires a dedicated section in the MCC or a floor-standing enclosure. Clearance requirements: 100 mm upwards, 75 mm downwards, 10 mm forwards, 0 mm backwards, 5 mm at the side. That backwards zero means it can sit flush against a back panel, saving depth in a shallow cabinet. Operating temperature range is -25... +60 °C, but note the derating requirement at 40 °C or above — above that ambient, the continuous rated current must be reduced. If the panel ambient hits 50 °C, expect to derate roughly 1-2% per degree above 40, depending on the load profile. Plan the enclosure ventilation accordingly.