Square D Q1B120 20A 1P 120V Circuit Breaker, Bolt-On | AmpState

Square D Q1B120 20A 1P 120V Bolt-On Circuit Breaker is a dependable, ready-to-install protection device for your electrical distribution needs. Designed for panelboards, load centers and related systems, this single-pole breaker delivers consistent overcurrent protection for 120-volt circuits while fitting seamlessly into your existing Square D setup.

Why choose the Q1B120 for your panel

• Exact part and BOM alignment: This model is purpose-built to match the Square D Q1B120 family, helping you keep your bill of materials aligned with the original specifications and simplifying spares management.
• Secure bolt-on mounting: The bolt-on design provides a rock-solid connection in demanding electrical environments, reducing the risk of loose connections and ensuring reliable operation over time.
• Precise electrical protection: With a 20A rating, 1-pole configuration and 120V operation, it protects individual circuits in residential and light commercial applications without unnecessary tripping on everyday load surges.
• Ideal for replacements and stock: A practical choice for service upgrades, panel maintenance, or stocking a spare that’s guaranteed to fit your original panel configuration.
• Support when you need it: Available from AmpState with guidance to confirm fit and compatibility, so you can proceed with confidence.

Key specifications

• Manufacturer: Square D
• Part Number: Q1B120
• Product Type: Circuit Breaker
• Amperage: 20 A
• Poles: 1 Pole
• Voltage: 120V
• Mounting: Bolt-On

Practical use cases and who benefits

• Residential or small commercial panelboards undergoing part replacement where the original Q1B120 is specified.
• Maintenance cabinets and service vans stocking BOM-aligned spares to reduce downtime during outages.
• Project installations that require consistent, repeatable bolt-on protection for individual 120V circuits.

How this breaker compares to alternatives (practical insights)

• Compared to plug-on equivalents, the bolt-on variant provides a more secure mechanical connection in panels subject to vibration or thermal cycling, helping prevent arcing or loose contacts.
• Choosing an exact Q1B120 ensures the trip characteristics and mounting footprint align with your existing Square D panel system, minimizing installation tweaks and compatibility questions.

Need help matching a part number or confirming compatibility? Message us and we’ll help you confirm fit.
Available from AmpState, this Q1B120 bolt-on breaker is a practical, reliable choice when you want to keep your electrical distribution running smoothly with components that truly align to the original design.