Equipped with the utmost functionality, SIRIUS 3RW55 Failsafe High Performance soft starters confidently handle even the most difficult starting and stopping operations. Thanks to innovative torque control, the device can be used for drives with an output of between 5.5 kW and 560 kW (at 400 V).

The innovative 3RW55 Failsafe soft starter features an integrated fail-safe digital input for directly connecting the EMERGENCY STOP, and thus covers SIL 1 STO applications. The HMI (with color display, local interface and a slot for micro SD memory card) and plug-in communication modules (PROFINET, PROFIBUS, EtherNet/IP and Modbus) ensure maximum flexibility. With their modern hybrid switching technology, the 3RW55 Failsafe soft starters offer efficient switching for long-term, energy-saving use.

The Siemens 3RW55 includes:

  • Automatic parameterization
  • Hybrid switching devices and three-phase motor control
  • Integration into the TIA portal – communication modules optional
  • Removable HMI with color display, local interface, and a slot for a micro SD memory card
  • Pump stop and torque control
  • Certified according to ATEX/IECEx directive
  • Fail-safe disconnection up to SIL 3 – PL e / STO

Benefits of the Siemens 3RW55 include:

  • Extremely easy commissioning and reliability even under changing load conditions
  • Minimum power loss and optimum/symmetrical motor control
  • Efficient configuration and maximum flexibility in automatic engineering
  • Maximum flexibility with regard to user interface and intuitive menu guidance
  • Reduced mechanical loading and optimum pump stop control
  • Suitable fort eh starting of explosion-proof motors
  • Reduced costs and space requirements thanks to direct wiring of the EMERGENCY STOP mushroom pushbutton to the soft starter for SIL 1

Questions? Contact our Engineering Team!


SE Automation, a Standard Electric Supply Co., in business since 2004, is committed to offering you, the customer, the quality services and products which you require to successfully run your business.