Soft Starters – 3RW30


For soft machine start-up and reduced mechanical stress.

The SIRIUS 3RW30 Basic Performance soft starters are suitable for soft starting of three-phase asynchronous motors.

Thanks to two-phase control, not only is the current kept at minimum values in all three phases throughout the entire starting time, but disturbing direct current components are also eliminated. This not only enables the two-phase starting of motors up to 55kW (at 400V) but also avoids the current and torque peaks which occur e.g. with star-delta starters.


Advantages at a glance:

  • Optimum adjustment to the drive application through separate potentiometers for starting voltage (40…100%) and start-up time up to 20 sec.
  • Minimum power loss through integrated bypass contacts after start-up completion
  • Up to 70% space savings in the control cabinet compared to star-delta combination
  • Reduced mounting costs and wiring through simple 4-wire motor supply line

Product characteristics/function

  • Small and compact design
  • Parameterization using potentiometers
  • Integrated in the SIRIUS modular system
  • Hybrid switching devices and two-phase motor control

Performance features/benefits

  • Space-saving, clearly arranged control panel layout
  • Simple and fast commissioning
  • Link modules to motor starter protectors
  • Minimum power loss and optimized motor control by avoiding DC components