The ABB E4N 4000 T LSI 3‑pole Air Circuit Breaker is a high‑capacity low‑voltage protective device from ABB’s Emax E4N series designed for three‑phase industrial and commercial power distribution systems. It combines a rugged breaker frame with an electronic protection trip unit (LSI) that provides coordinated and adjustable protection against overloads, short‑time faults, and instantaneous short circuits. The breaker comes with both fixed horizontal rear (FHR) and withdrawable (WMP) mounting options, allowing flexibility in switchgear installation and maintenance. The T designation typically indicates the inclusion of enhanced measurement, communication, or touch interface features on the trip unit. The NST suffix indicates compliance and classification related to the breaker version and frame style.

The ABB E3N3200 PR121/P‑LSIG 4‑pole WHR Air Circuit Breaker is a high‑capacity low‑voltage protective device from ABB’s SACE Emax E3N series designed for three‑phase power distribution systems. It incorporates a PR121/P‑LSIG electronic trip unit that provides adjustable protection against overload, short‑time, instantaneous, and ground fault conditions. The breaker’s withdrawable horizontal rear (WHR) configuration allows it to be easily removed from switchgear frames for maintenance or service without disconnecting main busbars. This type of circuit breaker is suited for use as a main distribution breaker or feeder protection in industrial and commercial switchgear.

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.

The ABB F2S 2500 A 4‑pole WMP Air Circuit Breaker is a high‑current low‑voltage protective device designed for three‑phase power distribution systems in industrial and commercial electrical installations. It belongs to ABB’s range of withdrawable (WMP) air circuit breakers, providing reliable protection and switching of electrical circuits carrying up to 2500 A of continuous current. The breaker interrupts fault currents and protects against overloads, short circuits and abnormal conditions when equipped with a suitable electronic trip unit. The WMP (withdrawable movable part) design allows the breaker to be safely inserted and removed from its switchgear frame for maintenance or inspection without disconnecting the main busbars, improving safety and uptime.

The ABB E2.2N 3‑pole Air Circuit Breaker is a low‑voltage protective device from ABB’s SACE Emax 2 E2.2N series designed for industrial and commercial three‑phase power distribution systems. It provides reliable overcurrent protection for electrical circuits and helps safeguard against overloads, short circuits and fault conditions when used with an appropriate electronic trip unit. The breaker series supports robust construction, high interrupting capacity, and flexible configuration options for fixed or withdrawable installations in switchgear and distribution panels. E2.2N breakers are suited for use as main distribution breakers or feeder protection breakers in power distribution networks.

The ABB E2S 2500 T LI 3‑pole WMP Air Circuit Breaker is a high‑capacity low‑voltage protective device designed for three‑phase AC power distribution systems. It belongs to ABB’s Emax 2 E2S series of draw‑out (“WMP” – Withdrawable Moving Part) air circuit breakers and features an electronic trip unit (“LI”) that provides coordinated long‑time, instantaneous, and other overcurrent protection functions. The breaker is suitable for use as a main distribution breaker or feeder protection breaker in industrial and commercial switchgear installations, offering reliable interruption of fault currents and easy maintenance thanks to its withdrawable design.

The ABB F4S 3200 4‑pole Air Circuit Breaker is a high‑current, low‑voltage protective device from ABB’s SACE F‑series (Megamax/Novomax class) designed for industrial and commercial three‑phase power distribution systems. It is rated at 3200 A continuous current and is built to handle heavy electrical loads with robust interruption performance. This breaker is used to protect electrical circuits against overloads, short‑circuits, and fault conditions, and can be installed in switchgear, distribution panels, and power distribution boards. Depending on configuration, the F4S frame can be fitted with an electronic trip unit (e.g., LSIG or PR1/P) to provide adjustable protective functions, status signaling, and optional communication/monitoring features. The 4‑pole design includes the neutral conductor for four‑wire systems.

The ABB PR121/P‑LSIG is an electronic overcurrent protection trip unit designed to be installed in compatible ABB low‑voltage air circuit breakers (ACBs). It provides adjustable and coordinated protection for three‑phase electrical distribution systems by detecting and responding to abnormal current conditions. The unit integrates multiple protection functions for comprehensive fault detection and system safety, including overload, short‑time currents, instantaneous short circuits, and ground faults. The PR121/P‑LSIG is suitable for industrial, commercial, and utility applications where reliable current protection, flexible coordination, and status indication are required.

The ABB E4S4000 PR121/P‑LI 3‑pole Fixed Horizontal Rear (FHR) Air Circuit Breaker is a high‑capacity low‑voltage protective device from ABB’s SACE Emax E4S series designed for industrial and commercial three‑phase power distribution systems. It includes an electronic PR121/P‑LI trip unit that delivers adjustable protection against overloads and instantaneous short‑circuit faults. The breaker is configured with fixed horizontal rear terminals, making it suitable for installation in switchgear and distribution cabinets where it functions as a main distribution breaker or feeder protection device.

The ABB PR121/P‑LI is an electronic overcurrent protection trip unit designed for integration into compatible ABB low-voltage air circuit breakers. It provides adjustable and coordinated protection for three-phase distribution systems, safeguarding against overloads and instantaneous short-circuit faults. The trip unit is suitable for industrial, commercial, and utility applications, ensuring reliable current protection and system safety.