Square D | LAL3640031M | Circuit Breaker | 400A | 3-Pole

Powerful protection for demanding electrical systems, the Square D LAL3640031M is a 400A, 3-Pole circuit breaker designed for maintenance, retrofit, and replacement tasks where exact specifications matter. Built by Square D, this unit provides reliable, coordinated disconnection across three phases when a fault occurs, helping safeguard downstream equipment and keeping downtime to a minimum.

Use this part number as your compatibility beacon: LAL3640031M. While shopping, confirm fit and ratings before ordering—the part number is the most reliable reference for matching panels and bus configurations.

Key advantages of the LAL3640031M

• 400A protection for high-current feeders and main circuits, ensuring robust protection for critical loads.
• Three-pole design suitable for three-phase systems, with a common-trip mechanism to shut down all phases simultaneously for safe service and maintenance.
• Precise compatibility identified by part number, simplifying sourcing and reducing the risk of mismatched replacements in Square D panel systems.
• Versatile for retrofit and replacements—a practical choice when upgrading existing installations or restoring uptime after faults.
• Reliability in demanding environments—designed to endure continuous operation in commercial and industrial applications.

Applications and use cases

Ideal for large feeders, main service upgrades, and retrofits in commercial, industrial, and data-center environments. Use cases include replacing aging breakers in Square D panels, upgrading to handle higher loads, or configuring a three-phase protection scheme for motors and heavy equipment. The 3-Pole configuration supports coordinated protection across all phases, reducing the risk of phase imbalance and equipment damage.

Installation and safety considerations

Installation should be performed by a qualified electrician following local electrical codes. Before any work, verify that power is isolated and that the panel is suitable for a 400A, 3-Pole device. Follow proper torque specifications for mounting and ensure clear labeling of circuit protections to support maintenance and emergency response. Keep the installation environment clean and dry to preserve performance over time.

Specifications at a glance

• : 400A
• poles: 3-Pole
• series: Square D LAL family
• part reference: LAL3640031M
• best practice: confirm fit and ratings against panel data sheet prior to purchase

For anyone upgrading a three-phase electrical system, the LAL3640031M offers a reliable, compatible solution that aligns with Square D’s panel ecosystems. By matching the correct part number, you simplify sourcing, reduce compatibility risk, and ensure robust protection for high-current applications.