3RW4047-1BB14, Soft Starter, 55 kW, 106 A, 200 to 480V AC

Siemens 3RW40 Soft Starter Series – Overview

Siemens 3RW40 soft starters are advanced compact motor starting solutions designed for smooth starting and stopping of three-phase asynchronous motors in industrial applications. The 3RW40 series focuses on reducing mechanical stress, limiting inrush current, and providing enhanced motor protection compared to basic soft starters. With integrated bypass functionality and flexible configuration options, Siemens 3RW40 soft starters are well suited for pumps, fans, compressors, conveyors, and general industrial machinery requiring reliable and efficient motor starting.

Product Description: 3RW4047-1BB14

The Siemens 3RW4047-1BB14 is a SIRIUS S3 frame motor soft starter rated for 106 A continuous current and specified for up to 55 kW at 400 V (30 kW at 230 V). It is designed for three-phase supply voltages in the 200–480 V AC range and accepts a control supply of 110–230 V AC/DC, making it suitable for global industrial panels. Typical motor compatibility is mid-size three‑phase induction motors in the 30 kW–55 kW range depending on system voltage; at 400 V it supports motors up to 55 kW, while at 230 V the applicable motor rating is 30 kW. This unit is aimed at applications that benefit from reduced mechanical and electrical stress at start and stop—common uses include pumps, fans, compressors, and conveyors where limiting inrush current, avoiding belt slip or water hammer, and extending drivetrain life are priorities. Model-specific features verified for this SKU include two‑phase control with adjustable start voltage (start-up voltage adjustable between ~40–100% of line), adjustable ramp-up and ramp-down (soft stop) and current limiting, integrated bypass contacts to reduce power loss during run, and built-in electronic motor overload and intrinsic device protection for reliable operation in standard cabinet environments.

Key Soft Starter Attributes