Siemens BQ1B040 - 40 A, 120 V, 1-Pole Bolt-On Circuit Breaker | AmpState

Siemens BQ1B040 is a 40A, 120V, 1-pole bolt-on molded case circuit breaker engineered for dependable branch circuit protection in panelboards and load centers. Built to endure in real-world electrical environments, it delivers consistent protection when it matters most.

• Bolt-on mounting: provides a secure, rigid bus connection with excellent vibration resistance, helping maintain reliable circuit protection in panels subject to movement or vibration.
• Thermal-magnetic trip unit: combines thermal sensing with magnetic tripping for stable, repeatable protection against both overcurrent conditions and short circuits, reducing nuisance trips and enhancing safety.
• OEM compatibility: designed to work seamlessly with matching Siemens load centers and panelboards, simplifying upgrades, replacements, and serviceability.
• Versatile application: suitable for residential, commercial, and light industrial environments—ideal for protecting critical branch circuits without oversizing equipment.
• 1-pole 40A 120V configuration: perfect for single-circuit protection on typical 120V systems, with the reliability of a molded case design and a clear, precise trip profile.

Technical specifications

• Manufacturer: Siemens
• Part number: BQ1B040
• 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

Use cases and scenarios

• Replacing a failed breaker in a Siemens panelboard or load center to restore proper circuit protection without wiring changes.
• Adding a dedicated 40A branch circuit for appliances or equipment in a residential or light commercial setting, with reliable trip performance.
• Upgrading existing panel infrastructure where a compact, bolt-on solution is preferred for secure connections and simplified maintenance.

With its precise thermal-magnetic protection, rigid bolt-on mounting, and OEM-friendly compatibility, the Siemens BQ1B040 delivers targeted, dependable protection for 120V circuits across homes, offices, and light industrial applications. Choose this breaker for a durable, reliable solution that aligns with Siemens panel centers and keeps your electrical system safeguarded.