The ABB PR122/P‑LSIG is an advanced electronic trip unit designed for use with ABB SACE series low‑voltage air circuit breakers. It integrates sophisticated microprocessor‑based protection logic to provide comprehensive circuit protection against overloads, short‑circuit currents, instantaneous faults, and ground (earth) faults. The unit supports adjustable protection stages — L (long‑time), S (short‑time), I (instantaneous), and G (ground fault) — giving flexible coordination and discrimination for power distribution and motor feeder applications. The trip unit also offers self‑diagnosis, event logging, and easy configuration via a front interface or external programming tool, making it suitable for industrial and commercial electrical systems requiring high levels of safety and reliability
