Siemens NGB2B125B - 125 A, 600 V, 2-Pole Bolt-On Circuit Breaker | AmpState

Meet the Siemens NGB2B125B 125 A, 600 V, 2-Pole Bolt-On Molded Case Circuit Breaker — a purpose-built solution for reliable branch circuit protection in panelboards and load centers. Designed for demanding environments, this breaker combines rugged mountability with precise protection, so your electrical system stays safe and productive.

• Secure bolt-on mounting: A rigid, vibration-resistant bus connection that stays tight and dependable even in equipment with frequent movement or vibration.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection against overloads and short circuits, adapting to temperature changes to minimize nuisance trips.
• Direct compatibility: Engineered to work seamlessly with matching Siemens OEM load centers and panelboards, simplifying replacement and expansion projects.
• Durable, molded-case design: Built to withstand everyday panel operation in residential, commercial, and light industrial settings.
• Two-pole, 125 A at 600 V: Ideal for protecting branch circuits that require solid, coordinated switching and clear, fast interruption.

Why it matters for your electrical system

The NGB2B125B isn’t just a breaker you install once. Its bolt-on mounting and thermal-magnetic protection address two core concerns: secure, long-lasting connections that resist loosening from vibration, and dependable trip performance that guards equipment and personnel by quickly interrupting fault conditions. This translates to fewer service calls, safer panels, and smoother operation of downstream circuits.

Ideal applications

• Residential panels where reliable, field-serviceable protection is required
• Commercial distribution boards that experience routine tool and equipment usage
• Light industrial panels needing solid, durable protection in moderately demanding environments
• Upgrade or replacement projects in Siemens OEM load centers and panelboards

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: NGB2B125B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 125 A
• Voltage Rating: 600 V
• Number of Poles: 2
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Whether you’re upgrading an existing panel, expanding a commercial distribution system, or stocking spare parts for reliable field service, the Siemens NGB2B125B delivers clear protection, straightforward installation, and long-term durability. Choose this bolt-on, two-pole solution for robust performance in residential, commercial, and light industrial electrical infrastructure.