Square D | A1B240 | Circuit Breaker | 40A | 2-Pole | 240V | Bolt-On

Protect critical circuits with precision using the Square D A1B240 40A two-pole 240V bolt-on circuit breaker. Engineered for maintenance, retrofit, and replacement projects, this breaker delivers dependable performance when exact specifications matter and secure mounting in compatible Square D panels is essential.

Key specifications

• Amperage: 40 A
• Poles: 2-Pole
• Voltage: 240 V
• Mounting: Bolt-On

Compatibility note: Confirm fit and ratings before ordering. Part number is the best reference for compatibility.

Why this Square D breaker stands out

This A1B240 bolt-on breaker is designed for secure, vibration-resistant mounting in panels that require a 2-pole, 240V protection device. Built by Square D, it offers reliable overcurrent protection for multiwire and branch circuits, helping to safeguard equipment and wiring in residential, commercial, or light industrial environments where exact spec matching is critical.

Ideal use cases

• Panel maintenance: replace worn or damaged breakers in 240V, 2-pole circuits with a like-for-like, bolt-on solution.
• Retrofit projects: upgrade or retrofit panels that require a 40A, 2-pole bolt-on breaker to maintain proper protection and code compliance.
• New installations within compatible Square D load centers: ensure you have the right form factor and voltage rating for reliable performance.

Installation and safety tips

• Power down the main and verify absence of voltage before handling any breakers.
• Match amperage, number of poles, voltage, and bolt-on mounting to your panel’s requirements, using the A1B240 as the compatibility reference.
• When in doubt about compatibility or wiring, consult a licensed electrician to ensure proper installation and protection.