Technical Parameters
Parameter Specification
Manufacturer ABB
Series / Family Emax E4S
Product Type Air Circuit Breaker (ACB), Fixed Horizontal Rear (FHR)
Model E4S4000 PR121/P‑LI
Number of Poles 3‑pole (three‑phase)
Rated Continuous Current (In) 4000 A
Trip Unit Type PR121/P‑LI electronic overcurrent release (Long‑time + Instantaneous)
Protection Functions Long‑time overload (L) and Instantaneous short‑circuit (I)
Rated Operational Voltage (Ue) Up to 690 V AC
Rated Insulation Voltage (Ui) 1000 V AC
Rated Impulse Withstand Voltage (Uimp) 12 kV
Short‑Circuit Breaking Capacity (Icu) ~75 kA
Service Short‑Circuit Breaking Capacity (Ics) ~75 kA
Short‑Time Withstand Current (Icw) ~75 kA (1 s / 3 s)
Rated Frequency 50 / 60 Hz
Mounting / Connection Fixed Horizontal Rear terminals (FHR)
Standards Compliance IEC low‑voltage circuit breaker standards
Typical Applications Main distribution breaker, feeder protection in industrial and commercial switchgear
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.