Technical Parameters Parameter Specification Manufacturer ABB Series / Family Emax E4S Product Type Low‑voltage Air Circuit Breaker (ACB) Model E4S4000 PR121/P‑LSIG Number of Poles 3‑pole (three‑phase) Rated Continuous Current (In) 4000 A Trip Unit Type PR121/P‑LSIG electronic overcurrent protection Protection Functions Long‑time (L) – overload protection Short‑time (S) – delayed fault protection Instantaneous (I) – high fault trip Ground fault (G) – earth fault protection 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) High interrupting capacity suitable for industrial low‑voltage networks Service Short‑Circuit Breaking Capacity (Ics) Matching the rated breaking capacity in service conditions Short‑Time Withstand Current (Icw) High withstand level for 1 s / 3 s durations Rated Frequency 50 / 60 Hz Mounting / Connection Fixed or withdrawable (depending on frame and switchgear configuration) Standards Compliance IEC low‑voltage circuit breaker standards Typical Applications Main distribution breaker, feeder protection in industrial/commercial switchgear