Siemens BL350 Circuit Breaker

Siemens BL350 is a three-pole, 50-amp molded‑case circuit breaker designed for panelboard installations in 240‑volt electrical systems. As part of the BL/B350 family, it employs a thermal‑magnetic trip mechanism to deliver precise overload protection and a 10 kA interrupt rating at 240 V. This bolt‑on breaker is built for panelboard mounting and provides common‑trip operation across all three poles, ensuring coordinated disconnection on a fault. With a 50 A rating, it is intended to guard feeders and distribution circuits in commercial or light‑industrial environments where a robust, field‑installable MCCB solution is required. Its BL frame designation and bolt‑on mounting differentiate it from plug‑in styles and align it with Siemens' legacy low‑voltage MCCB lineup. Catalogs and suppliers frequently list the unit as BL350 or B350, reflecting its 3‑pole, 240‑V, 50‑A, 10 kA‑rated specification for three‑phase protection. In practice, installers use the BL350 to shield branch circuits in panelboards and switchboards, where reliable, field‑mountable protection is needed without replacing the entire enclosure. Typical configurations place the BL350 in commercial electrical rooms or industrial applications where three‑phase loads demand quick, reliable disconnection during faults.