Eaton LD3400 - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

Meet the Eaton LD3400 — a 400A, 600V, 3-pole molded‑case circuit breaker designed for dependable branch‑circuit overcurrent and short‑circuit protection. Brought to you by AmpState, this unit pairs Eaton’s trusted engineering with a compact form factor that fits cleanly into panelboards and load centers, making it a reliable backbone for both new installs and panel upgrades.

Why the LD3400 stands out in real-world use

• Space‑efficient molded‑case design minimizes panel footprint, helping you maximize enclosure capacity without compromising protection.
• Thermal‑magnetic trip unit delivers stable, repeatable protection: the thermal element responds to gradual overcurrent, while the magnetic element provides an instantaneous trip for high‑energy faults, reducing the risk of damage to downstream equipment.
• 3‑pole configuration with common trip ensures synchronized disconnection across all poles in three‑phase circuits, enhancing safety and system reliability.
• 400A rating at 600V supports substantial branch circuits found in commercial and light industrial environments, while still suitable for demanding residential applications where large loads are present.
• OEM‑grade compatibility is designed to fit with matching Eaton OEM load centers and panelboards, delivering a seamless, reliable replacement or upgrade path.

Technical snapshot

• Part Number: LD3400
• Type: Thermal‑magnetic molded case circuit breaker
• Amperage Rating: 400A
• Voltage Rating: 600V
• Number of Poles: 3
• Applications: Branch circuit overcurrent and short‑circuit protection

Ideal for your projects

Perfect for residential installations requiring robust service reliability, commercial panelboards that demand strong fault protection, and light industrial applications where large loads are common. The LD3400’s compact design and reliable trip performance make it a practical choice for service panels, main distribution panels, and retrofit upgrades where space, safety, and long‑term durability matter.

Practical considerations and tips

• Verify that the enclosure and bus arrangement match the LD3400’s rating and OEM specifications to ensure a proper fit.
• Plan for coordinated protection by using the 3‑pole design where three‑phase circuits are present, ensuring all poles trip together during a fault.
• Keep maintenance simple by choosing compatible Eaton load centers and panelboards to preserve system integrity and OEM performance.