Square D | MEF436LS | Circuit Breaker | 400A | 3-Pole | 600V

Meet the Square D MEF436LS Circuit Breaker—a robust 400A, 3-Pole protector designed for demanding electrical environments. Rated for up to 600V, this unit is the reliable choice for maintenance, retrofit, and replacement projects where exact specifications matter.

Designed to integrate seamlessly with panels and equipment that accept the MEF family, the MEF436LS gives you a precise, compatible solution when matching existing safety and performance characteristics is essential. This isn’t a generic replacement—it's a specific, verified fit that helps minimize downtime and ensure continued system protection.

Key benefits that matter in the field

• 400A interrupting capacity provides robust protection for high-demand circuits typical in industrial and commercial settings.
• 3-Pole configuration supports balanced protection across three-phase systems, aiding in stable voltage and machine performance.
• 600V rating covers a wide range of distribution applications, helping you future-proof installations.
• The part number MEF436LS is the best reference for compatibility, making procurement and cross-checks straightforward.
• Specifically suitable for maintenance, retrofit, and replacement scenarios—minimizing disruption while restoring reliable protection.

Ideal use cases

• Upgrading or replacing aging breakers in existing panels that require exact MEF-series specifications.
• Retrofit projects where maintaining the original electrical characteristics is critical for system protection.
• New builds or service upgrades where a clearly defined 400A, 3-phase, 600V protection profile is needed.

Installation and compatibility tips

Before ordering, confirm fit and ratings to ensure a seamless match with your panel and wiring. Use the MEF436LS part number as the definitive reference when checking compatibility with your equipment and documentation. Follow standard electrical safety practices, verify panel labeling, and adhere to manufacturer guidelines during installation to ensure secure mounting and reliable operation.