Siemens 3RW52 Soft Starter 11–315 kW 25–570 A | Motor Soft Start

The Siemens 3RW52 soft starter ramps the motor voltage up smoothly at start and down at stop, reducing starting current, mechanical stress and water hammer. It is a compact, energy-efficient alternative to star-delta starters for pumps, fans, compressors and conveyors up to 11–315 kW.

Key features

• Soft start and soft stop with adjustable ramps
• Reduced starting current and torque peaks
• Integrated motor protection functions (model dependent)
• Built-in bypass for low heat losses (model dependent)
• Compact size compared to star-delta panels

Technical specifications

Available versions

Power Rating: 11 kW / 25 A, 15 kW / 32 A, 18.5 kW / 38 A, 22 kW / 47 A, 30 kW / 63 A, 37 kW / 77 A, 45 kW / 93 A, 55 kW / 113 A, 75 kW / 143 A, 90 kW / 171 A, 110 kW / 210 A, 132 kW / 250 A, 160 kW / 315 A, 200 kW / 370 A, 250 kW / 470 A, 315 kW / 570 A.

Typical applications

• Water and booster pumps (anti water-hammer)
• Fans and blowers
• Compressors and chillers
• Conveyors and crushers

Selection and installation tips

Select the soft starter by motor full-load current and duty (normal or heavy start), and check the number of starts per hour.

Frequently asked questions

Soft starter or VFD?

A soft starter controls only starting and stopping; a VFD also controls speed during operation and saves energy on variable-flow pumps and fans.

Buy Siemens 3RW52 in Egypt

Order the Siemens 3RW52 soft starter from Spark Egypt and receive a genuine product with an official tax invoice. We deliver to Cairo, Giza, New Cairo, 6th of October, Sheikh Zayed, the New Administrative Capital, Alexandria, the Delta, the Canal cities and Upper Egypt, and our engineers help contractors, installers and maintenance teams check ratings, accessories and cross-references before purchase. Request a quotation for bulk or project quantities.