Siemens 3RW3036 Soft Starter, 22 kW at 400 V, 11 kW at 230 V, 45 A

The Siemens 3RW3036 soft starter is a high-performance solution engineered for the smooth starting and stopping of three-phase asynchronous motors. By providing controlled voltage ramps, this device effectively minimizes mechanical stress on drive components and prevents high inrush current peaks that can destabilize power supply networks. Its compact design makes it an ideal choice for space-constrained industrial control cabinets, ensuring reliable motor operation and prolonged equipment longevity.

Advantages

This soft starter offers significant benefits by reducing the wear and tear on belts, gears, and couplings, which directly translates into lower maintenance costs and fewer production interruptions. The device ensures a gentle acceleration process that protects the motor windings from thermal stress. Furthermore, it helps maintain a stable electrical grid by preventing the voltage dips typically associated with direct-on-line starting methods, making it a robust component for modern industrial automation systems.

Suitable for

• Conveyor belt systems
• Industrial pumps and fans
• Compressor units
• Small machine tools
• Centrifugal machinery

This device may not be suitable for applications requiring high starting torque, as soft starters reduce the voltage to limit current, which inherently lowers the torque output during the ramp-up phase. It is also not intended for frequent reversing operations or heavy-duty starting cycles that exceed the thermal capacity of the unit.

Key specifications

• Rated operational power: 22 kW at 400 V, 11 kW at 230 V
• Rated operational current: 45 A
• Control supply voltage: 110-230 V AC/DC
• Operational voltage range: 200-480 V AC
• Size: S2

Installation should be performed by qualified personnel in accordance with local electrical regulations. The soft starter is mounted on a standard DIN rail or via screw mounting within a control panel. Ensure that the ventilation requirements are met to prevent overheating during operation. Connect the motor leads to the output terminals and the power supply to the input terminals, ensuring all connections are tightened to the specified torque settings.

What to consider before purchase

• Verify the motor's full load current matches the 45 A rating
• Ensure the control voltage matches your existing control system
• Check available space in the electrical cabinet for size S2 dimensions
• Confirm the application does not require high starting torque

For optimal performance and longevity, ensure the soft starter is installed in an environment free from excessive dust, moisture, and extreme temperatures. Regularly inspect terminal connections for tightness and verify that the cooling vents remain unobstructed during operation.