Siemens B140 - 40 A, 120 V, 1-Pole Bolt-On Circuit Breaker | AmpState

The Siemens B140 is a reliable, purpose-built protection device designed to keep branch circuits safe in panelboards and loadcenters. At 40A and 120V, this 1-pole bolt-on circuit breaker delivers sturdy, dependable overcurrent protection for everyday electrical loads in residential, commercial, and light industrial settings.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection for dependable performance and long-term reliability.
• Thermal-magnetic trip unit delivers stable, repeatable protection by reacting to both overload and short-circuit conditions, reducing nuisance trips and ensuring rapid response when faults occur.
• 1-pole, 40A, 120V design—compact, straightforward protection for individual circuits in panelboards and loadcenters.
• Molded case construction engineered for durability in demanding electrical environments.
• OEM-compatible with matching Siemens load centers and panelboards, making replacements and upgrades clean and hassle-free.

Why this matters: the combination of bolt-on mounting and a thermal-magnetic trip means you get a shielded, long-lasting breaker that stays firmly seated while offering precise protection tailored to your circuit’s needs. It’s a smart choice for systems that demand reliable fault protection without complex installation steps.

Technical Details

• Manufacturer: Siemens
• Part Number: B140
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Voltage Rating: 120V
• Number of Poles: 1
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal Use Scenarios

• Upgrading or replacing a failing breaker in residential panelboards or commercial loadcenters that require a 40A, 120V, single-pole device.
• Protecting individual circuit branches that feed heavy-load appliances or components operating at 120V.
• Situations where secure, vibration-resistant connections are important due to equipment location or ambient conditions.

Installation & Compatibility Tips

Pair this bolt-on breaker with Siemens OEM panelboards or loadcenters that support bolt-on protection devices. Ensure the panel is rated for the same voltage and that the circuit requires a 40A, 120V, 1-pole breaker. When installing, follow the panel manufacturer’s torque specifications to secure the breaker firmly to the bus, ensuring optimal electrical contact and reliable trip performance.