Siemens BL B370 Bolt-On 3-Phase Circuit Breaker

Siemens BL B370 Bolt-On 3-Phase Circuit Breaker is a panelboard-mountable molded‑case protector designed for three‑phase distribution, rated at 70 A and 240 V. This three-pole BL-series breaker uses a bolt-on, common-trip design to provide coordinated protection across all phases and is UL listed for use on 240 V circuits, with an interrupt rating typically specified at 10 kA at 240 V. The B370 designation identifies a 70 A, 3‑pole unit intended for installation in Siemens BL‑type panelboards or compatible bus systems, making it suitable for protecting feeders and branch circuits in commercial and light industrial distributions. As part of Siemens’ BL family, it complements other BL, BLH, and HBL bolt-on breakers in panelboard configurations and is specifically designed for secure attachment to compatible Siemens equipment.