Square D | A1L140 | Circuit Breaker | 40A | 1-Pole | 120V

Square D A1L140 circuit breaker is a reliable protective device engineered for precise compatibility in maintenance, retrofit, and replacement projects. This 40-amp, 1-pole unit operates at 120V and is identified by the part number A1L140, making it the clear choice when exact specifications matter.

Key specifications

• Amperage: 40A
• Poles: 1-Pole
• Voltage: 120V
• Part number: A1L140

Why choose the A1L140 for your project

Designed as a direct Square D replacement, the A1L140 prioritizes a precise fit within compatible panels, reducing the risk of misfit or performance issues common with generic substitutes. The part number A1L140 serves as the best reference for compatibility, ensuring you’re selecting a breaker that aligns with your panel’s design and ratings.

Fit, compatibility, and practical use

Before ordering, confirm fit and ratings to avoid mismatches. Use the A1L140 as your compatibility benchmark, cross-checking against your panel’s catalog number and the circuit’s 1-pole, 120V, 40A requirements. This breaker is ideal for:

• Routine maintenance on Square D installations where a precise 40A, 1-pole, 120V device is required
• Retrofits that demand exact specifications to maintain panel integrity and safety
• Replacement scenarios to restore original electrical protection without compromising performance

Practical tips for best results

• Keep a spare A1L140 on hand for planned maintenance or unexpected outages in compatible Square D panels.
• Handle breakers with dry hands and avoid forcing into panels to prevent damage to connectors.
• When in doubt, use the part number A1L140 as the definitive reference to verify compatibility with your Square D panel configuration.