Siemens 3RW4027-1BB04 Soft Starter System Module

Siemens 3RW4027-1BB04 is a SIRIUS Soft Starter S0 module for 3-phase motors, delivering 32 A at 40 °C and supporting up to 15 kW at 400 V. It accepts 200–480 V AC input and uses a 24 V AC/DC control interface; insulation voltage 600 V and thyristor blocking voltage up to 1,600 V. The unit includes an integrated bypass contact system, intrinsic device protection, motor overload protection, an external reset input, and an adjustable current limit to tailor soft-start performance; it is rated for 50–60 Hz operation. It employs screw-terminal connections and is designed for environments with pollution degree 3. This S0 starter from the Siemens SIRIUS family provides controlled motor start-ups while limiting inrush and mechanical stress in standard industrial automation panel installations. On the standard circuit, the operating voltage is 200–480 V with tolerance -15% to +10%, and the minimum load is 20% of the rated current. The combination of its 32 A rating, 200–480 VAC input, 24 V control, integrated bypass, and protection features supports reliable motor start-up control in standard industrial automation panels.