Siemens NSB-BQ2B040 Miniature Circuit Breaker

Siemens BQ2B040 Miniature Circuit Breaker is a 2‑pole, 40‑amp thermal‑magnetic protective device designed for 120/240‑V AC circuits, and it belongs to Siemens’ molded‑case BQ family. It delivers a common‑trip two‑pole protection with a 10 kA interrupting rating (10 kAIC) at 120/240V, making it suitable for protecting branch circuits in typical residential and light commercial panels. This bolt‑on version uses load‑lug terminals and is intended for secure field installation in compatible enclosures, ensuring simultaneous tripping of both poles for added safety. The BQ2B040 is a standard 120/240‑V, 2‑pole breaker intended for low‑voltage distribution applications and is documented by Siemens as a 2‑pole, common‑trip BQ series device with 10 kAIC capability.