ABB Softstarters – PSR, PSE and PSTX

ABB PSR, PSE and PSTX Softstarters are designed to provide controlled starting and stopping of three-phase asynchronous motors in industrial and commercial applications. By gradually controlling motor voltage and torque during startup and shutdown, these softstarters help reduce inrush current, electrical stress and mechanical wear on connected equipment. The product range covers rated motor currents from 3 A to 1,250 A, with higher current capacity available through inside-delta connections on selected PSTX models. Offering compact installation, integrated bypass technology and different levels of motor protection and communication functions, ABB softstarters provide flexible solutions for pumps, fans, compressors, conveyors and industrial machinery.

Controlled Motor Starting and Stopping

ABB softstarters regulate the voltage supplied to the motor during starting and stopping, helping reduce current peaks and mechanical stress on motors and driven equipment. Adjustable starting and stopping parameters allow users to match motor operation to different load conditions. Selected models also feature torque control to provide smoother acceleration and deceleration, particularly in pumping applications where controlled stopping helps reduce water hammer and pressure fluctuations.

Three Softstarter Series for Different Applications

PSR – The Compact Range

The ABB PSR series provides a compact and straightforward soft starting solution for small motors and space-limited installations. It focuses on essential soft start and soft stop functions, with an integrated bypass and a design capable of handling up to 100 starts per hour under specified operating conditions. When combined with a compatible ABB manual motor starter, PSR can form a compact motor starter assembly with overload and short-circuit protection.

PSE – The Efficient Range

The ABB PSE series is a general-purpose softstarter designed to balance starting performance, motor protection and cost efficiency. It features voltage ramp and torque control, adjustable current limitation, integrated electronic motor overload protection and a built-in bypass. Built-in Modbus RTU communication and an analog output for motor current measurement support convenient integration into industrial control systems. Its pump-oriented functions make it particularly suitable for water management and general industrial applications.

PSTX – The Advanced Range

The ABB PSTX series is an advanced softstarter designed for demanding motor starting applications and heavy-duty industrial loads. It provides comprehensive motor protection, advanced torque control, adjustable current limits and application-specific functions such as pump cleaning, motor braking and slow-speed jogging. Built-in Modbus RTU communication and support for additional industrial fieldbus protocols enable integration into more complex automation systems. Its graphical display and detachable keypad simplify configuration, monitoring and operation.

Integrated Bypass and Motor Protection

Selected ABB softstarter models feature an integrated bypass that connects the motor directly to the supply after the starting process is completed. This reduces power losses and heat generation during normal motor operation while simplifying panel wiring and installation. Motor protection capabilities vary across the three ranges, from basic starting functions on PSR to integrated electronic overload and more comprehensive protection functions on PSE and PSTX. Additional protective devices can be selected according to the motor and electrical system requirements.

Communication and System Integration

ABB softstarters support different levels of communication and control integration. The PSR range offers basic motor control and optional communication arrangements, while PSE includes built-in Modbus RTU communication. PSTX provides built-in Modbus RTU and supports additional industrial communication protocols through compatible Anybus modules. These options enable integration with PLCs, industrial controllers and supervisory systems for motor status monitoring and process management.

Industrial Applications

ABB PSR, PSE and PSTX softstarters are suitable for a wide range of motor-driven applications, including:

• Pumping Systems: Controlled starting and stopping of water supply, circulation and industrial process pumps.

• Fans and Ventilation: Reduced starting current and mechanical stress for industrial fans and ventilation equipment.

• Compressors: Controlled motor starting for industrial air and process compressors.

• Conveyor Systems: Smooth motor starting for material handling and production line equipment.

• Mining and Minerals: Motor control for crushers, mixers, mills and heavy-duty processing machinery.

• Water and Wastewater Treatment: Pump control and protection for water management and treatment facilities.

• Industrial Manufacturing: Motor starting and stopping for production equipment and automated machinery.

Model Selection and Technical Specifications

ABB offers three softstarter ranges with different current ratings and functional capabilities:

PSR – Compact Range

• Rated Motor Current: 3–105 A.

• Main Operational Voltage: 208–600 V AC.

• Control Supply Voltage: 100–240 V AC or 24 V AC/DC.

• Main Functions: Soft start, soft stop and integrated bypass.

• Application Focus: Small motors and compact installations.

PSE – Efficient Range

• Rated Motor Current: 18–370 A.

• Main Operational Voltage: 208–600 V AC.

• Control Supply Voltage: 100–250 V AC.

• Main Functions: Torque control, current limitation, electronic motor overload protection, built-in bypass and Modbus RTU.

• Application Focus: General-purpose motor control, particularly pumps and water applications.

PSTX – Advanced Range

• Rated Motor Current: 30–1,250 A, with up to 2,160 A for selected inside-delta configurations.

• Main Operational Voltage: 208–690 V AC.

• Control Supply Voltage: 100–250 V AC.

• Main Functions: Advanced torque control, comprehensive motor protection, current limitation, motor braking, pump cleaning and fieldbus communication.

• Application Focus: Heavy-duty motors and demanding industrial processes.