RSBT4025EV21HP is a three-phase controlled soft starter designed for scroll compressors, featuring a patented auto-adaptive algorithm that automatically optimizes inrush current reduction without user settings. It operates at 400 VAC with a rated operational current of 25 Arms at 40°C and supports an assigned compressor rating of 11.0 kW (10.0 HP). The unit includes integrated bypass relays for reduced heat dissipation, a ramp-up time of less than 600 ms, and a maximum current limit level of 90 Arms. It features over-temperature, overcurrent, and locked rotor protection, with an HP version optimized for multi-compressor systems and high pressure starts. The V21 version includes DIN mount with RFPMV00 module ready mounted, making it suitable for HVAC and refrigeration applications requiring reliable compressor soft starting.