Siemens B2125 - 125 A, 240 V, 2-Pole Bolt-On Circuit Breaker | AmpState

The Siemens B2125 is a dependable, high-performance 125A, 240V, two-pole bolt-on molded case circuit breaker designed to protect branch circuits in panelboards and load centers. Its robust bolt-on mounting delivers a rigid, vibration-resistant bus connection, helping maintain reliable protection even in environments with equipment vibration or movement.

• 125A at 240V – ideal for safeguarding sizable feeders and critical loads in residential, commercial, and light industrial settings.
• 2-pole design – provides complete 240V protection for circuits that require two hot legs and a common trip.
• Bolt-on mounting – ensures a secure, long-lasting connection to the bus, reducing the risk of loose contacts and nuisance trips.
• Thermal-magnetic trip unit – combines thermal overload protection with magnetic short-circuit protection for stable, repeatable performance.
• OEM compatibility – engineered to match Siemens OEM panelboards and load centers for a clean, reliable fit.
• Versatile applications – suitable for residential panels, commercial distribution, and light industrial circuits where dependable overcurrent protection is critical.

Why the B2125 matters for your electrical safety

In everyday electrical systems, consistent protection against overcurrent and short circuits is non-negotiable. The B2125’s bolt-on design locks into place for a solid bus connection, minimizing movement that can compromise touch-safe clearances and electrical continuity. The thermal-magnetic trip unit reacts to real fault conditions, delivering prompt protection for high-inrush loads without excessive nuisance tripping, so you can rely on protected circuits day in and day out.

Use cases and ideal scenarios

Choose the B2125 when you need a rugged, 2-pole solution for 240V circuits such as large appliances, main feeders, HVAC equipment, water heating, or lighting and receptacle circuits in spaces where panel security and stable operation are essential. It’s the practical choice for replacements in Siemens-compatible panelboards, ensuring continuity of protection without compatibility concerns.

Specifications at a glance

• Manufacturer: Siemens
• Part Number: B2125
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 125A
• Voltage Rating: 240V
• Number of Poles: 2
• Mounting Style: Bolt-on
• Application
• Branch circuit overcurrent and short-circuit protection

For reliable, site-tested protection that fits seamlessly with Siemens panels, the B2125 stands out as a practical, long-term solution. It delivers the protection your electrical system demands with a mounting and trip design that ensures consistent performance across residential, commercial, and light industrial environments.