The ABB E3H1250 PR121/P‑LI 3‑pole WHR Air Circuit Breaker is a high‑performance low‑voltage protective device from ABB’s SACE Emax E3 series designed for three‑phase electrical distribution systems. It incorporates an electronic PR121/P‑LI trip unit, which provides adjustable protection against overloads, short‑time faults, instantaneous short circuits, and optionally ground faults (depending on configuration). The breaker is configured with a withdrawable horizontal rear (WHR) mounting style, allowing it to be safely removed from switchgear for maintenance or inspection without disconnecting the main busbars. This model is typically used as a main distribution breaker or feeder protection in industrial and commercial switchgear installations where reliable coordination and fault clearing are essential.
