Description

The ABB PSR25 is an electronic soft starter rated at 25 A for three-phase induction motors up to 11 kW at 400 V, providing smooth and controlled motor acceleration to reduce inrush current and mechanical stress during starting. Part of ABB’s PSR series, the PSR25 covers the important 11 kW motor size commonly used in pump, fan, and compressor applications in building services, industrial processing, and agricultural installations. The soft start function reduces the peak starting current typically to less than twice the motor’s full-load current, significantly reducing the impact on supply networks and mechanical transmission systems.

The PSR25 complies with IEC 60947-4-2 and mounts on standard 35 mm DIN rail for easy integration into motor control panels. The two-parameter adjustment system (initial voltage and start time) provides sufficient control flexibility for most standard pump and fan applications while keeping commissioning straightforward. The device uses thyristor pairs in each phase to control the voltage applied to the motor during acceleration, with a bypass contactor recommended for continuous operation to eliminate thyristor losses during the motor running period.

Compatible with ABB’s range of contactors and motor protection relays for co-ordinated motor starter design, the PSR25 is used in building services pump and fan starters, water pumping stations, conveyor drive panels, and general industrial motor control panels where soft starting of 11 kW motors is required. Its DIN rail format and simple adjustment make it a practical and cost-effective solution for panel builders and electrical contractors seeking reliable soft start performance for medium-sized motors without the cost and complexity of a variable speed drive.