WEG SSW900 Bypass Soft Starter with Integrated Bypass Contactor

The WEG SSW900 Bypass Soft Starter is WEG's flagship soft starting solution for medium and large induction motors in the 30 A to 810 A current range, distinguished by its integrated bypass contactor that connects the motor directly across the line after run-up is complete — eliminating continuous current flow through the thyristors, reducing steady-state power losses to near zero, and allowing the SSW900 to be sized at the motor's starting current requirement rather than the running current, resulting in a smaller and more cost-effective device than competing soft starters without bypass. The SSW900 addresses the full spectrum of medium-to-large motor starting duties in Saudi Arabia's industrial and utility sectors: pump, compressor, fan, conveyor, and mill applications where direct-on-line starting would cause unacceptable supply voltage dips, mechanical shock, or water hammer in pipeline systems.

The SSW900's control philosophy includes a torque-controlled soft start mode that ramps motor torque linearly from a programmable starting torque to rated torque, providing mechanical stress reduction superior to voltage-ramp control in applications with high-inertia loads or belt-drive systems sensitive to jerk. A pump control function with adjustable deceleration ramp prevents water hammer in pipeline systems by controlling the rate of speed reduction on pump stop — a feature highly valued by NWC and MARAFIQ water system engineers who manage large-diameter pipeline networks with pump stations across Saudi Arabia. The integrated Modbus RTU and optional PROFIBUS/EtherNet/IP communication cards allow the SSW900 to report motor current, voltage, thermal state, and fault history to plant SCADA or DCS systems, providing the same motor health data visibility previously only available with higher-cost motor protection relay and starter combinations.

Saudi Arabia's utility water sector operates one of the world's largest networks of medium and large pump motor installations — NWC alone manages more than 8,000 pumping stations across the Kingdom — and the SSW900's combination of soft starting, pump ramp control, and bypass operation makes it the preferred technology for replacing ageing auto-transformer starters and star-delta starters in pump station refurbishment programmes. ARAMCO's offshore and onshore facilities operate large centrifugal and reciprocal compressor motor starters where supply voltage disturbance from DOL starting can upset adjacent sensitive process equipment; the SSW900's controlled starting reduces PCC voltage dip to less than 3%, within ARAMCO's electrical network specification limits. SABIC industrial city utilities operate large chilled water, cooling water, and process pump motors where NEC 430 and IEC 60947-4-2 soft starter specifications are standard project requirements.

Razz Middle East stocks the SSW900 in the most common current ratings — 72 A, 105 A, 142 A, 190 A, 250 A, 320 A, 430 A, 590 A, and 810 A — for rapid delivery to Saudi projects. We provide starter sizing calculations, parameter setting guidance, and commissioning support. The SSW900 is supplied with English and Arabic documentation. Contact Razz Middle East for a soft starter sizing proposal and SAR quotation for your pump or motor starting application.