Siemens NGB1B040B - 40 A, 347 V, 1-Pole Bolt-On Circuit Breaker | AmpState

The Siemens NGB1B040B is a dependable, single-pole bolt-on circuit breaker engineered for reliable branch circuit protection in panelboards and load centers. With a 40A rating and a 347V maximum, it’s built to handle typical commercial and residential distribution needs while delivering consistent performance in diverse environments.

Key Features

• Bolt-on mounting delivers a rigid, vibration-resistant bus connection for long-term stability in busy electrical panels.
• Thermal-magnetic trip unit provides stable, repeatable protection by coordinating between overload (thermal) and short-circuit (magnetic) conditions.
• 1-pole design suited for single-phase circuits, making it ideal for branch circuits in homes, offices, and light industrial spaces.
• 347V rating broadens compatibility with common commercial and industrial distribution schemes.
• OEM-compatible with matching Siemens panelboards and load centers, ensuring a seamless, code-compliant fit.

Why this breaker stands out

Unlike generic replacements, the NGB1B040B is purpose-built for Siemens panelboards, delivering a precise fit and electrical characteristics that align with your system’s protection requirements. The bolt-on design minimizes connection looseness and vibration-induced trips, while the thermal-magnetic trip unit adapts to load changes, reducing nuisance trips and protecting conductors and devices downstream from damage.

Ideal Applications

• Residential subpanels and service panels needing reliable overcurrent protection on single-phase circuits
• Commercial lighting and receptacle circuits that require robust protection at the distribution level
• Light industrial equipment circuits where compact, dependable protection is critical
• Retrofits or upgrades in existing Siemens electrical systems that require a compatible, bolt-on breaker

Technical Snapshot

Manufacturer: Siemens
Part Number: NGB1B040B
Type: Thermal-magnetic molded case circuit breaker
Amperage Rating: 40A
Voltage Rating: 347V
Number of Poles: 1
Mounting Style: Bolt-on
Application: Branch circuit overcurrent and short-circuit protection

Practical guidance for use

• Ensure your panelboard is a compatible Siemens OEM unit to guarantee performance parity and code compliance.
• Use in circuits where a single-pole, 40A protection scheme is appropriate to safeguard wiring and connected loads from overloads and short circuits.
• In environments with vibration or frequent mechanical activity, rely on the bolt-on mounting to maintain a solid, long-lasting electrical connection.
• Pair with proper conductors and enclosures per local electrical codes and Siemens installation guidelines for optimal safety and reliability.