Siemens B2125H - 125 A, 240 V, 2-Pole Bolt-On Circuit Breaker | AmpState

Meet the Siemens B2125H — a 125A, 240V, 2-pole bolt-on molded case circuit breaker built to deliver reliable branch circuit protection in panelboards and loadcenters. Designed for installations where secure mounting and precise protection matter, this breaker stands up to demanding residential, commercial, and light industrial environments.

Why this breaker stands out

• Rigid bolt-on mounting provides a secure, vibration-resistant bus connection, reducing the risk of loose contacts that can compromise protection and performance.
• Thermal-magnetic trip unit combines dependable overload protection with fast magnetic response for short circuits, delivering stable, repeatable protection across varying loads.
• OEM-ready compatibility is designed to pair with matching Siemens OEM load centers and panelboards, ensuring a seamless fit and consistent electrical characteristics.
• Versatile application suitable for residential, commercial, and light industrial projects where safe, reliable circuit protection is a must.

Technical overview

• Amperage rating: 125 A
• Voltage rating: 240 V
• Poles: 2
• Mounting style: Bolt-on
• Type: Thermal-magnetic molded case circuit breaker
• Part number: B2125H

Ideal use cases

Use the Siemens B2125H when you need robust protection for 240V branch circuits in a panelboard or load center. It’s an excellent choice for replacing aging breakers in Siemens panels, adding circuits for 240V equipment (such as central air systems or large appliances), or consolidating protection in spaces with vibration-prone equipment where a solid, bolt-on connection matters.

Practical installation and maintenance notes

Choose this breaker when your equipment requires a bolt-on solution and a match to Siemens panels. Verify panel compatibility with OEM specifications to ensure a proper fit and coordinated trip characteristics. This unit protects against overcurrent and short circuits, helping maintain electrical safety and system reliability across daily operations in homes, offices, and light industrial settings.