Siemens NGB2B045B - 45 A, 600 V, 2-Pole Bolt-On Circuit Breaker | AmpState

The Siemens NGB2B045B is a 2-pole bolt-on molded case circuit breaker engineered to safeguard branch circuits with dependable overcurrent and short-circuit protection. Rated for 45A and up to 600V, it’s built to perform reliably in panelboards and load centers across residential, commercial, and light industrial environments.

Why this breaker stands out

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, reducing the risk of loose terms or connection movement in demanding install environments.
• Thermal-magnetic trip unit delivers stable, repeatable protection by combining overload (thermal) protection with fast magnetic response to short-circuits, helping to minimize nuisance trips and safeguard equipment.
• OEM-compatible design is optimized to fit matching Siemens load centers and panelboards, ensuring proper mechanical fit and electrical coordination.
• Versatile application suited for a wide range of installations—from home electrical panels to light commercial and industrial panels—where robust branch-circuit protection is needed.
• Durable construction and molded-case insulation for long-lasting performance in everyday electrical systems.

Key specifications

• Manufacturer: Siemens
• Part number: NGB2B045B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 45 A
• Voltage rating: 600 V
• Poles: 2
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Practical use cases

Install the NGB2B045B in panelboards or load centers to protect feeders and branch circuits serving HVAC equipment, lighting, receptacle circuits, small motors, and other steadily loaded loads. Its 2-pole design is ideal for 240V circuits or paired hot conductors common in modern residential and light commercial electrical systems.

Installation and maintenance tips

• Ensure the breaker is paired with a compatible Siemens panelboard for optimal fit and trip coordination.
• Mount using the bolt-on method to secure a solid bus connection; verify torque and seating per panel specifications to maintain reliability in vibrations or temperature cycling.
• Use as part of a well-coordinated protection scheme—pair with appropriately rated upstream devices and downstream branch protections to optimize selectivity and safety.

With its robust bolt-on mounting, precise thermal-magnetic protection, and OEM compatibility, the Siemens NGB2B045B 45A 600V 2-pole breaker is a dependable choice for ensuring safe, reliable power distribution across residential, commercial, and light industrial panels.