The ABB PR122/P‑LSI is an advanced electronic protection trip unit designed for use in ABB low‑voltage circuit breakers (such as E3S and similar breaker families) for 3‑pole, high‑current applications up to 2500 A and 3200 A. It provides comprehensive overcurrent protection by integrating multiple protection stages — Long‑time (L) for overloads, Short‑time (S) for delayed short‑circuit response, Instantaneous (I) for immediate fault clearing, and (where supported) Ground‑fault (G) detection. The PR122/P‑LSI unit is microprocessor‑based and allows adjustable protection settings for precise coordination with upstream and downstream protective devices. It can be configured via front panel interfaces or external programming tools, offering flexibility for industrial power distribution, main feeder protection, and motor feeder applications.
