Siemens BQ3B040 40A 3P 240V Circuit Breaker, Bolt-On | AmpState

The Siemens BQ3B040 is a bolt-on, three-pole circuit breaker built for reliable protection of 240-volt distributions in panelboards, load centers, and electrical distribution systems. Designed for everyday electrical work, this 40-amp unit helps keep your power circuits safe, stable, and compliant with original equipment specifications.

• Amperage: 40 A
• Poles: 3
• Voltage: 240 V
• Mounting: Bolt-On
• Manufacturer: Siemens
• Part Number: BQ3B040
• Applications: panelboards, load centers, electrical distribution

Why this matters in real-world installations? If you’re upgrading, repairing, or expanding an electrical system, using the exact original part number—BQ3B040—ensures seamless mounting, correct bus bar interaction, and predictable tripping performance. The bolt-on design delivers a secure mechanical connection that’s well-suited for retrofit projects and spare-part stocking, helping you maintain a clean BOM and minimize compatibility surprises when you’re cycling through replacements.

Key use cases

• Replacement projects where the panel originally specified a 3P 240V, 40A bolt-on breaker
• Stocking spares to keep the BOM aligned with the original Siemens part number
• Retrofits in commercial or industrial panelboards and distribution centers
• Maintenance inventories for service calls that require exact-fit replacements

What makes the BQ3B040 stand out

• Direct alignment with Siemens panelboard and load-center configurations that expect a bolt-on 3-pole, 240V device
• Consistency in electrical protection characteristics, reducing the risk of mismatched trip curves or mounting issues
• Easy integration into existing assemblies where the original part number is preserved for BOM accuracy

If you’re unsure about fit or compatibility, we can help. Need help matching a part number or confirming compatibility? Message us and we’ll help you confirm fit.

Designed for professionals who demand dependable circuit protection with straightforward installation, the Siemens BQ3B040 delivers solid performance when you’re managing panelboard protection, distribution reliability, and spare-part readiness. Add it to your procurement list for a precise, reliable upgrade or replacement that stays true to the original specifications.