Eaton HMCP400K5X - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

Designed for dependable branch-circuit overcurrent and short-circuit protection in panelboards and load centers, the Eaton HMCP400K5X is a 400 A, 600 V, 3-pole molded case circuit breaker built to perform in demanding residential, commercial, and light industrial environments. Its compact footprint makes efficient use of panel space, while delivering robust protection where it’s most needed.

Why this breaker stands out

• Space-efficient molded case design: A compact form factor that helps maximize panel capacity without sacrificing protection.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection by combining overload (thermal) and short-circuit (magnetic) mechanisms for precise fault clearing.
• Three-pole configuration: Ensures simultaneous disconnection of all phases in a 3-phase system, enhancing safety and coordination in balanced electrical networks.
• OEM-compatible: Specifically designed to match and work with matching Eaton OEM loadcenters and panelboards for seamless integration and reliable performance.
• Versatile application range: Ideal for residential panels, commercial service entrances, and light industrial distribution where dependable protection is essential.

Technical snapshot

• Amperage rating: 400 A
• Voltage rating: 600 V
• Poles: 3
• Type: Thermal-magnetic molded case circuit breaker
• Manufacturer: Eaton
• Part number: HMCP400K5X

What problems does it solve?

This breaker is purpose-built to protect branch circuits from overloads and short circuits, reducing the risk of equipment damage and fire hazards. By delivering fast, reliable trip responses and stable protection across a range of loads, it helps facilities maintain continuous operation with fewer unexpected outages.

Ideal use scenarios

• Replacing or upgrading protection in residential service panels that require a robust 3-pole solution.
• Feeding commercial load centers and panelboards where space is at a premium but protection cannot be compromised.
• Protecting feeders in light industrial electrical distribution with three-phase systems up to 600 V.
• Retrofits or new installations where OEM compatibility ensures correct fit and coordinated protection with existing equipment.

Installation and care tips

• Refer to Eaton installation guidelines to ensure correct termination and safe operation.
• Verify panel compatibility to maintain proper coordination with downstream devices and panelboard design.
• Use as part of a thoughtfully designed protection strategy that considers conductor sizes, downstream protection, and system fault currents.

Why choose the Eaton HMCP400K5X

Beyond basic specs, this 400 A, 600 V, 3-pole molded case breaker offers dependable, repeatable protection with a form factor that respects panel space and OEM compatibility. It’s a practical, durable choice for professionals who require reliable protection for critical electrical infrastructure in a variety of settings.