The ABB F5S 4000 A is a low‑voltage air circuit breaker (ACB) from ABB’s legacy SACE Megamax F5S series. It is designed for heavy‑duty electrical distribution and industrial protection applications where high continuous currents and reliable fault interruption are required. This model is configured as a three‑pole (3P) device with a fixed mounting format (denoted by the “F” in the designation), intended to be permanently installed directly onto busbars in switchboards, distribution panels, or motor control centers.
