Siemens B370 70A 3P 240V Circuit Breaker, Bolt-On | AmpState

Meet the Siemens B370: a bolt-on, three-pole circuit breaker built for dependable protection in everyday electrical work. With a 70 A rating and 240 V, this device is designed to handle 3‑phase distribution in panelboards, load centers, and electrical distribution systems. It’s especially valuable for retrofit projects and maintenance planning where keeping the exact part number matters, making the B370 a trusted choice for consistent, long‑term service.

Key specifications at a glance

• Amperage: 70 A
• Poles: 3
• Voltage: 240V
• Mounting: Bolt-On
• Part number: B370
• Manufacturer: Siemens
• Application: Circuit protection in panelboards, load centers, and electrical distribution networks

Why this Siemens B370 stands out

Unlike generic replacements, the B370 is purpose-built for Siemens panel environments, delivering secure, bolt-on mounting that simplifies retrofit and maintenance cycles. The 3‑pole design protects three phases in one compact unit, making it ideal for commercial spaces, industrial feeders, and any 3‑phase distribution where reliable protection is non-negotiable. Its consistency with the B370 part number ensures streamlined stocking and faster service when part availability matters most.

Best-use scenarios

• Retrofit projects where you must preserve the exact part number for compatibility and future maintenance
• Electrical distribution upgrades in panelboards and load centers that service commercial or light‑industrial loads
• Spare‑part planning for facilities that rely on Siemens protection devices to minimize downtime during replacements

Installation considerations

The bolt-on design is intended for compatible Siemens panelboards and load centers. Before installation, confirm that the panel supports a 3P 240V, 70A bolt-on breaker of the B370 family. Ensure proper mounting and secure fasteners per standard electrical practices to maintain reliable overcurrent protection for your circuits.

Support and availability

AmpState carries the Siemens B370, with expert assistance available to help you confirm fit and compatibility. If you’re matching a part number or verifying panel compatibility, message us and we’ll help you confirm the right fit for your system.

Who benefits most

• Electricians performing panelboard retrofits or service upgrades
• Facilities managers coordinating maintenance schedules for critical electrical distribution
• Engineers specifying reliable, consistent protection devices for 3‑phase systems