Siemens BF240 - 40 A Circuit Breaker | AmpState

Introducing the Siemens BF240 — a reliable 40A molded case circuit breaker designed to guard your panelboard or load center from overcurrent and short-circuit events. Built for dependable branch circuit protection, it delivers precise performance where it matters most, so you can run loads with confidence.

Efficient, space-conscious protection

The compact molded case design maximizes panel space without compromising protection. Whether you’re updating a residential panel or outfitting a small commercial setup, the BF240 fits neatly into tight enclosures, helping you keep layouts clean and organized while meeting electrical safety standards.

Thermal-magnetic protection you can trust

The thermal-magnetic trip unit combines two layers of defense: a thermal element that responds to sustained overloads and a magnetic mechanism that delivers an instant trip for dangerous short circuits. This dual-action design provides stable, repeatable protection across varying temperatures and load conditions, reducing nuisance trips and safeguarding wiring and devices.

Designed for seamless integration

Compatibility with matching Siemens OEM load centers and panelboards means straightforward replacement or expansion. Ideal for residential, commercial, and light industrial applications, the BF240 integrates into existing Siemens ecosystems with predictable performance and mechanical fit.

Technical snapshot

• Manufacturer: Siemens
• Part Number: BF240
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40A
• Application: Branch circuit overcurrent and short-circuit protection

Use cases and practical scenarios

Use the BF240 to protect individual branch circuits in residential panels powering lighting and receptacles, or to safeguard feeders and circuits in small commercial installations. Its compact form factor and reliable trip characteristics make it a practical choice for panel upgrades, circuit additions, or new construction where Siemens panel hardware is specified.

What makes this breaker stand out

Beyond generic protection, the BF240 is engineered to align with Siemens panelboard architecture, delivering consistent trip curves and terminal compatibility. This means fewer compatibility surprises during installation and more predictable electrical behavior once in service.

Tips for optimal use

• Confirm compatibility with your specific Siemens panelboard model to ensure proper mounting and terminal sizing.
• Keep a spare BF240 on hand for quick replacements during maintenance or expansion projects.
• Periodically inspect connections for signs of overheating, and ensure the breaker is seated firmly in the bus to maintain reliable performance.