Schneider Electric A1B340 Molded Case Circuit Breaker

Schneider Electric's A1B340 Molded Case Circuit Breaker is a three-pole MCCB rated for 40 A at 240 V, designed to protect three‑phase distribution circuits in commercial and light industrial panels. This device, part of the legacy Square D line now under Schneider Electric, uses a rugged molded housing and a compact form factor that fits standard MCCB enclosures used in typical panelboards and switchgear. It provides branch‑circuit protection for 3P 240 V circuits, making it suitable for feeders and loads such as motors, pumps, and large lighting installations in service entrances, mechanical rooms, and distributed power zones. The A1B340 designation specifies the current rating and three‑pole configuration, enabling straightforward cross‑reference with replacement breakers for legacy installations. When selecting this breaker, verify your panel is designed for a three‑pole, 240 V service and confirm compatibility with upstream protection and bus connections. With its robust construction and familiar Square D heritage, the A1B340 offers reliable overcurrent protection for electrical distribution systems that rely on 240 V three‑phase power.