SIRIUS soft starter S0 38 A-3RW4028-1BB04

Product Description

SIRIUS Soft Starter S0 38 A – 3RW4028-1BB04

The Siemens 3RW4028-1BB04 is a high-performance SIRIUS soft starter from the 3RW40 series, designed for smooth starting and stopping of three-phase induction motors up to 18.5 kW (400 V). It reduces starting current peaks, mechanical stress, and voltage dips, ensuring safe and efficient motor operation in industrial applications.

This model belongs to the S0 frame size, making it suitable for compact control panel installations. It is widely used in pumps, fans, compressors, conveyors, HVAC systems, and general industrial machinery, where controlled acceleration and deceleration improves system reliability and equipment life.

According to Siemens technical data, this soft starter supports 38 A rated current, 200–480 V AC supply, 24 V AC/DC control voltage, integrated bypass contact system, and thyristor-based voltage ramp control, making it a reliable solution for medium-power motor starting applications.

🔹 Key Features

• Siemens SIRIUS 3RW40 series soft starter
• Part Number: 3RW4028-1BB04
• Frame size: S0
• Rated current: 38 A
• Motor power: Up to 18.5 kW at 400 V
• Supply voltage: 200–480 V AC, 3-phase
• Control voltage: 24 V AC/DC
• Soft start and soft stop function for smooth motor control
• Integrated bypass contact system for reduced heat loss after starting
• Thyristor-based phase control for controlled acceleration
• Adjustable current limiting and ramp time settings
• Built-in motor overload protection
• Compact modular design for panel efficiency
• Screw terminal connection for secure wiring
• Complies with IEC 60947-4-2 standards