Eaton HMCP400F5Y - 400 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Meet the Eaton HMCP400F5Y — a robust 400A, 600V, 3-pole bolt-on molded case circuit breaker designed to deliver dependable branch circuit protection in today’s panelboards and load centers. Built to stand up to real-world conditions, it ensures reliable performance where it matters most, from residential panels to light commercial and industrial installations.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, helping maintain consistent electrical continuity even in environments with movement or equipment vibration.
• Thermal-magnetic trip unit delivers stable, repeatable protection against overcurrent and short circuits. The magnetic element responds quickly to faults, while the thermal element manages gradual overloads for reduced nuisance trips.
• OEM-compatible design is engineered to be used with matching Eaton OEM load centers and panelboards, enabling straightforward replacements and seamless system upgrades without adapters or rework.
• Versatile applications suited for residential, commercial, and light industrial environments, protecting feeders and branch circuits across a range of load profiles and equipment.

Technical specifications

• Manufacturer: Eaton
• Part Number: HMCP400F5Y
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400A
• Voltage Rating: 600V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases

• Upgrading or retrofitting feeders in residential panelboards that require solid, code-compliant protection for large-capacity circuits.
• Installing in commercial load centers where reliable 3-pole protection is needed for three-phase feeds or equipment with multiple conductors.
• In light industrial panels where stable trip characteristics and vibration resistance help minimize downtime and electrical faults.

Why choose this breaker

The HMCP400F5Y stands out with a bolt-on installation that reinforces mechanical integrity, a precise thermal-magnetic trip that adapts to both steady loads and fault conditions, and full compatibility with Eaton’s OEM panel offerings. This combination reduces installation complexity, enhances protection reliability, and simplifies maintenance and future panel upgrades.

Installation and maintenance tips

Install according to applicable electrical codes and the panelboard manufacturer’s instructions. Use the proper torque specifications for bolt-on connections as prescribed by Eaton and ensure all conductors are clean and properly terminated. Periodically inspect for signs of overheating or abnormal wear, and verify that the trip unit remains responsive after any fault or maintenance activity.