Eaton HMCP400J5X - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

The Eaton HMCP400J5X is a robust 400A, 600V, 3-pole molded case circuit breaker designed to safeguard branch circuits in panelboards and loadcenters. Its compact form optimizes panel space while delivering dependable protection for demanding electrical layouts in commercial, residential, and light industrial settings.

• Compact molded case design: Maximizes usable space inside your panelboard for easier routing and future expansion.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection by combining thermal overload sensing with magnetic short-circuit interruption for fast, reliable response.
• 3-pole configuration: Ideal for 3-phase distribution, enabling coordinated protection across all phases in modern commercial and light industrial systems.
• OEM panelboard compatibility: Engineered to be compatible with matching Eaton OEM loadcenters and panelboards, ensuring seamless integration and consistent protection.
• High-voltage capability: 600V rating supports a wide range of commercial and industrial applications demanding higher voltage distribution.

Technical snapshot

• Manufacturer: Eaton
• Part Number: HMCP400J5X
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400A
• Voltage Rating: 600V
• Number of Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Why this breaker matters for your project

Whether you’re outfitting a new commercial panel, upgrading a distribution center, or adding subpanels in a light-industrial setting, the HMCP400J5X provides precise, reliable protection where it counts. The thermal-magnetic trip mechanism minimizes nuisance trips while delivering decisive action during short-circuit events, helping to protect wiring, devices, and downstream equipment. Its 3-pole design ensures synchronized protection across all phases, which is essential for balanced loads and safe operation of motors and HVAC systems commonly found in business environments.

Practical use cases and installation notes

• Use as a main or feeder breaker in commercial panelboards and load centers to shield large branch circuits from overcurrent.
• Ideal for 3-phase equipment rooms, data centers, and light industrial equipment rooms where reliable 600V protection is required.
• Choose this unit when you need OEM-panel compatibility to maintain performance parity with existing gear and to simplify replacement ordering.
• Ensure proper alignment with system protection schemes and follow all local electrical codes during installation and commissioning.

From AmpState, the Eaton HMCP400J5X delivers durable, high-capacity protection designed to keep complex electrical systems safe and running. If you’re upgrading panel protection or selecting a compatible MCCB for your distribution scheme, this 3-pole 400A breaker pairs precisely with Eaton’s loadcenters and panelboards to deliver consistent performance and peace of mind.