3RW3047-1BB14, Soft Starter, 55 kW, 106 A, 200 to 480V AC

Siemens 3RW30 Soft Starter Series – Overview

Siemens 3RW30 soft starters are compact and cost-effective motor starting solutions designed for basic soft starting of three-phase asynchronous motors in standard industrial applications. The 3RW30 series focuses on reducing mechanical stress and limiting inrush current during motor start-up, providing a simple and reliable alternative to direct-on-line starting. With a straightforward design and easy commissioning, Siemens 3RW30 soft starters are well suited for pumps, fans, compressors, conveyors, and other simple motor-driven machines where basic motor starting control is sufficient.

Product Description: 3RW3047-1BB14

The Siemens 3RW3047-1BB14 is a SIRIUS 3RW30 series soft starter sized S3, rated for 106 A (at 40 °C) and specified for motors up to 55 kW at 400 V (30 kW at 230 V) in the standard circuit. It is designed for supply voltages from 200 to 480 V AC with a control supply of 110–230 V AC/DC, and operates at 50–60 Hz. The device uses thyristor power electronics with an integrated bypass contact system (built-in bypass contactor) to reduce heat dissipation during run and improve efficiency after start-up. Typical applications include pumps, fans, compressors and conveyor drives where a compact, low-complexity motor soft starter is required.

Important engineering notes for procurement and system design: the 3RW3047-1BB14 provides soft starting and built-in bypass but does not include intrinsic motor overload protection or thermistor evaluation inside the unit, so a separate motor protection relay or overload device is required where overload or locked-rotor protection is needed. Connections are via screw terminals; the product is intended for straightforward panel mounting and simple integration into standard control systems.

Key Soft Starter Attributes