Description

The ABB PSR37 is an electronic soft starter rated at 37 A for three-phase induction motors up to 18.5 kW at 400 V, delivering controlled voltage ramp starting to minimise current peaks and mechanical shock associated with direct-on-line motor starting. Part of ABB’s PSR soft starter series, the PSR37 is designed for the 18.5 kW motor size used in medium-duty industrial and commercial applications including large pump and fan drives, compressor starters, and process machinery. Its thyristor voltage control provides an adjustable start ramp that significantly reduces inrush current and extends motor and mechanical system service life.

Compliant with IEC 60947-4-2, the PSR37 mounts on 35 mm DIN rail and integrates into standard industrial control panel designs. The adjustable initial voltage and ramp time parameters are set using front-panel potentiometers, enabling straightforward site commissioning without specialised tools or software. A bypass contactor is recommended for continuous operation to eliminate the thyristor power dissipation during the motor running phase, improving overall system efficiency and protecting the soft starter from thermal overload in high-duty applications.

The PSR37 is widely used in water pumping stations, building services ventilation systems, industrial process plant, material handling conveyors, and compressor drives where smooth starting of 18.5 kW motors is required. It is compatible with ABB’s co-ordinated motor protection and contactor products, and ABB provides selection tables for designing fully protected motor starter assemblies around the PSR37. Panel builders and electrical contractors will find it a reliable and practical soft starter option for medium-sized motor applications where current limitation and load protection during starting are important requirements.