soft starter

Product Details

Soft Starter 3RW44 for High Feature Application

Order No: 3RW44..-…..

In addition to soft starting and soft ramp-down, the solid-state SIRIUS 3RW44 soft starters provide numerous functions for higher-level requirements. They cover a performance range up to 710 kW (at 400 V) in the inline circuit and up to 1200 kW (at 400 V) in the inside-delta circuit.

The SIRIUS 3RW44 soft starters are characterized by a compact design for space-saving and clearly arranged control cabinet layouts. For optimized motor starting and stopping the innovative SIRIUS 3RW44 soft starters are an attractive alternative with considerable savings potential compared to applications with a frequency converter. The new torque control and adjustable current limiting enable the High-Feature soft starters to be used in nearly every conceivable task. They guarantee the reliable avoidance of sudden torque applications and current peaks during motor starting and stopping. This creates savings potential when calculating the size of the switchgear and when servicing the machinery installed. Be it for inline circuits or inside-delta circuits – the SIRIUS 3RW44 soft starter offers savings especially in terms of size and equipment costs.

The bypass contacts already integrated in the soft starter bypass the thyristors after a motor ramp-up is detected. This results in a further great reduction in the heat loss occurring during operation of the soft starter at rated value.

Combinations of various starting, operating and ramp-down possibilities ensure an optimum adaptation to the application-specific requirements. Operation and commissioning can be performed with the menu-controlled keypad and a menu-prompted, multi-line graphic display with background lighting. The optimized motor ramp-up and ramp-down can be effected quickly, easily and reliably by means of just a few settings with a previously selected language. Four-key operation and plain-text displays for each menu point guarantee full clarity at every moment of the parameterization and operation.



  • Soft starting with breakaway pulse, torque control or voltage ramp, adjustable torque or current limiting as well as any combination of these, depending on load type
  • Integrated bypass contact system to minimize power loss
  • Various setting options for the starting parameters such as starting torque, starting voltage, ramp-up and ramp-down time, and much more in three separate parameter sets
  • Start-up detection
  • Inside-delta circuit for savings in terms of size and equipment costs
  • Various ramp-down modes selectable: free ramp-down, torque-controlled pump ramp-down, combined DC braking
  • Solid-state motor overload and intrinsic device protection
  • Thermistor motor protection
  • Keypad with a menu-prompted, multi-line graphic display with background lighting
  • Interface for communication with the PC for more accurate setting of the parameters as well as for control and monitoring
  • Simple adaptation to the motor feeder
  • Simple mounting and commissioning
  • Display of operating states and fault messages
  • Connection to PROFIBUS and PROFINET with optional PROFIBUS DP or PROFINET module
  • External displays and operator modules
  • Mains voltages from 200 to 690 V, 50 to 60 Hz
  • Can be used up to 60 °C (derating from 40 °C)




  • Pumps
  • Fans
  • Compressors
  • Water transport
  • Conveyor systems and elevators
  • Hydraulics
  • Machine tools
  • Mills
  • Saws
  • Breakers
  • Mixers
  • Centrifuges
  • Industrial refrigerating and deep-freezing plants