Square D FA34040 I-Line Molded Case Circuit Breaker

The Square D FA34040 I-Line Molded Case Circuit Breaker is a 40 A, three‑pole protective device built on the FA frame for 480 VAC three‑phase systems and designed to plug into Square D I‑Line panelboards via line‑side I‑Line connections. This thermal‑magnetic molded‑case breaker uses both long‑time and instantaneous trip functions to manage fault currents and delivers an 18 kA short‑circuit rating at 480 VAC. The FA34040 is intended for feeder or branch‑circuit protection in industrial and commercial installations that rely on 480 VAC three‑phase power, with a line‑side I‑Line connection and ABC phase terminals to simplify wiring in compatible panelboards. Compatible with legacy and newer I‑Line systems, it provides per‑phase disconnection of all three conductors when tripped, helping to safeguard equipment and maintain electrical system integrity in demanding environments.