Siemens NGB1B025B - 25 A, 347 V, 1-Pole Bolt-On Circuit Breaker | AmpState

Siemens NGB1B025B is a 25A, 347V, 1-pole bolt-on molded case circuit breaker designed to protect single–phase branch circuits in panelboards and load centers. Engineered for dependable overcurrent and short-circuit protection, this unit combines robust mounting with precise thermal-magnetic protection to keep electrical systems safe and reliable in everyday operation.

Why this bolt-on breaker stands out

• Secure bolt-on mounting delivers a rigid, vibration-resistant bus connection, reducing the risk of loose connections in panels that experience movement or vibration.
• Thermal-magnetic trip unit provides stable, repeatable protection by responding to overloads (thermal) and short circuits (magnetic) without nuisance trips.
• 1-pole, 25A, 347V configuration is ideal for protecting a single circuit in commercial and residential systems where 347V service is present.
• OEM compatibility is designed to work with matching Siemens load centers and panelboards, ensuring proper coordination and seamless replacement in existing installations.
• Versatile application suitable for residential, commercial, and light industrial environments requiring reliable branch circuit protection.

Practical use cases

• Replacing aging breakers in Siemens OEM panelboards within small commercial offices or retrofit projects that utilize 347V distribution.
• Protecting individual lighting or receptacle circuits fed from 347V systems in mixed-use facilities.
• Upgrading panel configurations to maintain consistent protection characteristics and easier maintenance across a facility.
• Installing in load centers where vibration tolerance and secure bus connections are valued for long-term reliability.

Technical snapshot

• Manufacturer: Siemens
• Part Number: NGB1B025B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 25 A
• Voltage Rating: 347 V
• Number of Poles: 1
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Note: This component is intended for use with matching OEM Siemens panelboards and load centers. Verify that your panel is rated for 347V operation and that the NGB1B025B is a compatible replacement for your specific model before installation.