Hot Picks Square D A1B140 – 40A 1 Pole Molded Case Circuit Breaker

Part of the classic A1B series, this 40A single-pole molded case circuit breaker delivers thermal-magnetic protection for commercial and industrial environments. It operates at 120VAC with a 10kAIC interrupt rating. Designed specifically for bolt-on applications, it mounts into vintage Square D NA1B panelboards. When panel upgrades are required, this unit is replaced by the QOB140 using a specialized retrofit kit.