Siemens SIRIUS 3RW4027-1TB04 Soft Starter, 32 A, 400-600 V AC, 24 V AC/DC Control, 15 kW at 400 V

The Siemens SIRIUS 3RW4027-1TB04 soft starter stands out with its integrated bypass function, which reduces heat generation and energy consumption during continuous operation. Unlike conventional starters, it provides smooth, 2-phase controlled starting and stopping for three-phase asynchronous motors, minimizing mechanical stress and current peaks.

Highlights

• Rated operating current: 32 A at 40°C
• Wide voltage range: 400–600 V AC
• Control supply: 24 V AC/DC
• Integrated bypass for energy efficiency
• Soft start and soft stop functions
• Screw terminals and DIN rail/screw mounting

In daily use

This soft starter is ideal for applications requiring gentle motor ramp-up and ramp-down, such as pumps, fans, and conveyor systems. Its compact design and IP20 protection make it suitable for control cabinet installation. The integrated bypass reduces power loss, lowering operating costs over time.

Full specifications

• Product type: Soft starter
• Series: SIRIUS 3RW40
• Control principle: 2-phase controlled
• Rated operating current: 32 A
• Rated operating voltage: 400–600 V AC
• Rated control supply voltage: 24 V AC/DC
• Rated power at 400 V: 15 kW
• Rated power at 230 V: 7.5 kW
• Integrated bypass: Yes
• Overload protection: No
• Connection type: Screw terminals
• Mounting type: DIN rail / screw mounting
• Protection class: IP20
• Ambient operating temperature: -25 to +60 °C
• Number of phases: 3-phase
• Motor type compatibility: Three-phase asynchronous motors
• Standards/approvals: IEC 60947-4-2, UL, CSA, CE, CCC

Final note

Engineered for reliability in industrial environments, the 3RW4027-1TB04 ensures smooth motor operation and extended equipment life.