Siemens B240 - 40 A, 240 V, 2-Pole Bolt-On Circuit Breaker | AmpState

Siemens B240 40A, 240V, 2-pole bolt-on molded case circuit breaker delivers reliable, real-world protection for your electrical system. Engineered for dependable branch-circuit overcurrent and short-circuit protection in panelboards and load centers, this breaker is built to keep critical circuits safe from faults while maintaining steady operation in everyday use.

• Bolt-on mounting: a secure, rigid bus connection that resists vibration and maintains consistent electrical contact, even in busy equipment rooms or areas with frequent activity.
• Thermal-magnetic trip unit: combines a heat-based overload element with an instantaneous magnetic trip for fast response to short circuits, delivering stable and repeatable protection performance.
• OEM-compatible design: specifically designed to pair with matching Siemens load centers and panelboards for straightforward installation and reliable performance.
• Versatile for multiple environments: suitable for residential, commercial, and light industrial applications, protecting 40A branch circuits at 240V with two poles.

The Siemens B240 is a thermal-magnetic molded case circuit breaker (MCCB) rated at 40A and 240V, featuring a 2-pole configuration that ensures simultaneous disconnect of both conductors for enhanced safety. Its bolt-on mounting provides a robust connection that resists loosening over time, making it an excellent choice for panels that experience vibration, temperature cycling, or heavy equipment startup transients.

• Manufacturer: Siemens
• Part Number: B240
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Voltage Rating: 240V
• Number of Poles: 2
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal for electricians and facility owners looking for a dependable protection device that integrates cleanly with Siemens OEM panelboards. Use cases range from upgrading aging panels and safeguarding critical feeders to enabling safe operation of commercial lighting, receptacle circuits, HVAC feeders, and light industrial equipment. When you need a proven, easy-to-install solution that minimizes nuisance trips while delivering precise protection, the Siemens B240 stands out as a practical, long-lasting choice.

Pro tips for best results: ensure your panelboard is compatible with bolt-on MCCBs, torque mounting hardware to the manufacturer’s specifications, and follow standard electrical safety practices during installation. With the B240, you’re choosing a consistent, predictable protection partner for your 40A branch circuits at 240V.