Square D FA14040B - 40 A, 1-Pole Plug-In Circuit Breaker | AmpState

The Square D FA14040B is a 40 A, 1-pole plug-in molded case circuit breaker engineered for dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Designed for residential, commercial, and light industrial environments, this breaker delivers fast, reliable protection where it matters most, so electrical systems stay safe and productive.

Key advantages that matter in the field

• Fast plug-in connection enables quick installation and effortless replacement in existing panels, minimizing downtime during upgrades or repairs.
• Thermal-magnetic trip unit provides stable, repeatable protection by reacting to overloads (thermal) and short circuits (magnetic) with precise timing, reducing nuisance trips.
• OEM-compatible design is crafted to fit matching Square D load centers and panelboards, ensuring seamless compatibility and dependable performance.
• Single-pole, 40 A configuration offers targeted protection for individual branch circuits, helping to safeguard wiring and connected devices without unnecessary shutdowns.
• Versatile for multiple applications—well suited for residential service panels, light commercial setups, and selective industrial installations where reliable circuit protection is essential.

What problems does it solve?

Overcurrent events and short-circuit faults can cause damage, downtime, and safety concerns. The Square D FA14040B provides immediate, predictable response to these threats, protecting conductors and devices on the protected circuit while maintaining system continuity for all other circuits. Its plug-in design reduces installation errors and simplifies field replacements, so maintenance crews can service panels quickly without unnecessary downtime.

Ideal use cases

• Residential panelboards needing dependable 40 A protection for dedicated circuits like HVAC feeders or water heating equipment.
• Commercial panel installations where quick replacements and reliable trip performance are critical for uptime.
• Light industrial control panels requiring a robust, plug-in molded case breaker that aligns with Square D OEM components.

Compatibility & installation tips

Designed to work with matching Square D panelboards and load centers, the FA14040B is selected when OEM compatibility and consistent trip characteristics matter. For best results:

• Verify that your panel is designed for plug-in molded case breakers of this type and rating.
• When replacing an existing breaker, ensure the new unit is the correct part number (FA14040B) to maintain the panel’s protection profile.
• Follow manufacturer torque specifications on the terminal connection to ensure a secure, long-lasting electrical connection.
• Always power down equipment and follow safety procedures when performing panel work or replacements.

Specifications at a glance

• Manufacturer: Square D
• Part Number: FA14040B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 40 A
• Number of Poles: 1
• Mounting Style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection

Why this matters for you

Choosing the Square D FA14040B means prioritizing reliable protection with predictable trip behavior and streamlined maintenance in panels you already own or plan to install. Its plug-in format reduces service time, while its thermal-magnetic mechanism delivers protection that adapts to varying loads, helping prevent damage and downtime across homes, offices, and light industrial spaces. When you need a dependable 40 A, 1-pole solution that integrates cleanly with Square D OEM panels, the FA14040B is a smart, efficient choice.