The ABB E4S4000 PR121/P‑LSIG is a high‑capacity low‑voltage air circuit breaker from ABB’s Emax E4S series designed for industrial and commercial three‑phase power distribution systems. It is equipped with the PR121/P‑LSIG electronic trip unit, which provides coordinated and adjustable protection against overloads, short‑time faults, instantaneous short circuits, and ground faults. This breaker is suitable for use as a main distribution breaker or feeder protection device in electrical switchgear and distribution panels, offering dependable fault interruption and system reliability.
