Siemens BQ3B100U Three Phase Circuit Breaker

Siemens BQ3B100U is a 100 A, three-pole molded‑case circuit breaker in the BQ family, rated for 240 V AC and designed for bolt‑on mounting. It provides a 10 kA short‑circuit interrupt rating at 240 V and uses a thermal‑magnetic trip with long‑time and instantaneous trip functions, configured for common‑trip protection across all three poles. The unit features load‑side lug terminals and is categorized as a low‑voltage molded‑case breaker suitable for panelboard installation in commercial and light‑industrial environments. As a standard BQ type MCCB, it is intended to protect three‑phase distribution circuits up to 100 A, ensuring rapid disconnection under fault conditions. Typical applications include feeders and branch circuits within electrical panels where reliable 100 A protection and coordinated trip across phases are required.