3RW5055-6AB14, Soft Starter, 75 kW, 143 A, 200 to 480V AC

Siemens 3RW50 Soft Starter Series – Overview

Siemens 3RW50 soft starters are high-performance motor starting solutions designed for demanding industrial applications requiring reliable control of three-phase asynchronous motors. The 3RW50 series focuses on reducing mechanical stress, limiting inrush current, and supporting higher motor power ratings compared to compact soft starters. With robust construction and advanced motor protection capabilities, Siemens 3RW50 soft starters are well suited for heavy-duty applications such as large pumps, compressors, conveyors, mixers, and industrial process machinery where dependable motor starting is critical.

Product Description: 3RW5055-6AB14

The Siemens 3RW5055-6AB14 SIRIUS soft starter is specified for medium‑to‑large three‑phase motors and delivers a rated operational current of 143 A. It supports a supply voltage class of 200–480 V AC and is rated for standard three‑phase motor power of 75 kW when connected in a 400 V system (and 37 kW at 230 V), making it a fit for pumps, compressors, conveyors and other industrial drives in the 75 kW class. This model uses screw‑type power terminals and provides an analog output for process monitoring or PLC integration; its control supply accepts 110–250 V AC control voltage. The 3RW5055-6AB14 is intended for installations where reducing mechanical stress and limiting inrush current are required while retaining straightforward integration into existing control systems. Typical users are electrical engineers and procurement teams specifying soft starters to replace or upgrade star-delta starters, reduce maintenance from mechanical starting, and improve network disturbance during motor starting. Practical benefits for procurement and engineering teams include clear motor size mapping (37 kW @230 V / 75 kW @400 V), a conventional control-voltage option (110–250 V AC), and an analog feedback output for simple status or ramp monitoring without requiring fieldbus modules.

Key Soft Starter Attributes