Eaton | MD3400 | Circuit Breaker | 400A | 3-Pole

The Eaton MD3400 Circuit Breaker is a rugged, high-capacity protection solution engineered for demanding three-phase electrical systems. With a 400A rating and 3-Pole configuration, this unit delivers reliable, coordinated shutdown across all phases to prevent equipment damage and downtime. This particular part is the MD3400 model, a trusted choice for maintenance, retrofit, and replacement projects where exact specifications matter.

• Amperage: 400A
• Poles: 3-Pole (three-phase protection)
• Part number: MD3400 – use this reference to verify compatibility
• Ideal for: maintenance, retrofit, and replacement scenarios in industrial or commercial electrical setups

Why choose the Eaton MD3400 in your electrical distribution plan? It’s designed to align with Eaton panel systems and compatible assemblies, reducing the risk of mismatch that can complicate procurement or installation. By selecting the exact MD3400 with a 400A, 3-Pole configuration, you gain a dependable, single-part solution that streamlines stocking, ensures consistent trip characteristics, and supports safe and predictable protection for three-phase loads.

Who is this ideal for? Plant engineers, facilities managers, and electricians responsible for maintaining or upgrading three-phase distribution in factories, data centers, commercial buildings, and other industrial environments. If your project involves replacing aging breakers, upgrading capacity, or retrofitting panels to handle higher loads, this unit helps you achieve a fast, reliable transition with minimal compatibility risk.

Use cases and practical scenarios

• Replacing an aging or failed 400A, three-phase breaker in a distribution panel
• Retrofits where a three-pole, 400A protection device is required to upgrade capacity
• Maintenance shutdowns and service interruptions planned around a compatible MD3400 replacement
• New installations that demand a verified Eaton MD3400 part number for seamless integration

How it compares to alternatives A genuine Eaton MD3400 400A 3-Pole breaker provides precise trip curves and mounting compatibility that generic or aftermarket parts often lack. By choosing the MD3400, you benefit from guaranteed alignment with Eaton’s distribution panels and accessories, smoother maintenance cycles, and a lower risk of compatibility surprises during retrofit projects.

Important note: Confirm fit and ratings before ordering. Use the MD3400 part number as the best reference for compatibility with your Eaton panels and accessories to ensure a safe, code-compliant installation.