Description

The ABB PSR12 is a compact electronic soft starter for three-phase induction motors up to 5.5 kW at 400 V, designed to provide controlled motor acceleration and deceleration, reducing the mechanical stress and electrical inrush current associated with direct-on-line motor starting. The PSR12 is rated at 12 A and is one of the smallest members of ABB’s PSR series, making it ideal for space-constrained control panels and applications where motor starting performance must be improved without the complexity of a full variable speed drive. It provides adjustable start voltage and start ramp time settings to optimise starting performance for the specific motor and load.

The PSR12 complies with IEC 60947-4-2 for electronic motor starters and is designed for DIN rail mounting within standard control panels. The soft starter controls the voltage applied to the motor during starting, gradually ramping up the voltage from an adjustable initial level to full voltage over a user-defined time period. This controlled start reduces peak current demand on the supply, minimises mechanical shock to the driven load, and extends the service life of both the motor and the mechanical transmission system. A bypass contactor is recommended for continuous operation to eliminate the power dissipation of the thyristors after run-up is complete.

The PSR12 is widely used for pump, fan, compressor, and conveyor applications where smooth starts are required to protect pipework, belt drives, or fluid handling systems from mechanical shock. It is compatible with ABB contactor accessories for bypass operation and is supported by ABB’s technical documentation for co-ordinated motor control system design. The compact format and simple pot-adjustment controls make the PSR12 a practical choice for electrical panel builders and engineers looking for an entry-level soft start solution for small motor applications.