Eaton HLD3400 - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

The Eaton HLD3400 is a 400A, 600V, 3-pole molded case circuit breaker designed to safeguard your electrical distribution with precise, dependable protection. Built for panelboards and loadcenters, this breaker delivers reliable branch circuit overcurrent and short-circuit protection without compromising panel space or layout.

Why the HLD3400 stands out

• Compact molded-case design optimizes panel space, making it easier to fit complex distribution schemes in tighter enclosures.
• Thermal-magnetic trip unit delivers stable, repeatable protection by combining a thermal element for sustained overloads with a magnetic element for fast short-circuit interruption.
• Three-pole configuration provides coordinated protection across all three phases, essential for balanced three-phase systems.
• OEM-grade compatibility designed to align seamlessly with matching Eaton OEM load centers and panelboards for straightforward installation and reliable trip coordination.
• Versatile across settings suitable for residential, commercial, and light industrial applications where dependable overcurrent protection is critical.

Technical snapshot

• Manufacturer: Eaton
• Part number: HLD3400
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 400 A
• Voltage rating: 600 V
• Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Practical benefits and use cases

In a commercial panel or light-industrial distribution system, the HLD3400 acts as a reliable first line of defense against overloads and sudden faults. Its compact form helps maximize the usable space in main distribution panels, while the thermal-magnetic trip mechanism minimizes nuisance trips caused by minor temperature swings and transient surges. Ideal scenarios include:

• Feeding critical circuits in panelboards where space is at a premium
• Protection of three-phase loads in commercial equipment rooms
• Subpanel protection in light industrial installations
• Replacement or upgrade of legacy breakers within Eaton-compatible load centers

How it supports safe, reliable operation

The HLD3400’s protective performance translates to fewer unplanned outages and more stable electrical systems. Its coordinated trip behavior helps ensure that only the affected circuit opens during a fault, preserving service continuity on unaffected feeders. By pairing a robust 400 A rating with a 600 V capability, it’s well-suited for medium-scale distribution where space, reliability, and ease of installation matter most.