Siemens NGB1B045B - 45 A, 347 V, 1-Pole Bolt-On Circuit Breaker | AmpState

Siemens NGB1B045B is your reliable, purpose-built solution for protecting branch circuits in panelboards and loadcenters. This 45A, 347V, 1-pole bolt-on molded case circuit breaker is engineered to deliver dependable overcurrent and short-circuit protection where it matters most—in residential, commercial, and light industrial electrical distributions.

1. Secure bolt-on mounting — The bolt-on design provides a rigid, vibration-resistant bus connection, ensuring a dependable ride through the bumps and vibration of everyday operation. This means fewer loosening issues and more consistent protection over time.
2. Thermal-magnetic trip unit — Combines a thermal element for steady overload protection with a magnetic trip for swift short-circuit response. The result is stable, repeatable protection performance that minimizes nuisance trips and quickly isolates faults when they occur.
3. OEM-compatible reliability — Specifically engineered to be compatible with matching Siemens OEM loadcenters and panelboards, helping you maintain proper coordination within your distribution system without compatibility surprises.
4. Versatile applications — Ideal for a range of settings: residential panels for branch-circuit protection, light commercial installations (lighting or receptacle feeders), and light industrial distributions where compact, reliable protection is required.

Key specifications

• Manufacturer: Siemens
• Part Number: NGB1B045B
• Type: Thermal-magnetic molded case circuit breaker (MCCB)
• Amperage Rating: 45 A
• Voltage Rating: 347 V
• Number of Poles: 1
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Whether you’re upgrading an existing Siemens panel or stocking a replacement for service calls, the NGB1B045B delivers a precise fit and predictable protection you can trust. Its focused 45 A rating and 347 V capability cover common commercial and residential distribution needs, while the single-pole design keeps layouts simple and efficient. For technicians seeking a durable, plug-and-play option that aligns with Siemens’ ecosystem, this bolt-on MCCB is a straightforward, long-term solution that reduces downtime and helps keep electrical systems safe and compliant.