Eaton KDB3400 - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

The Eaton KDB3400 is a 3-pole molded-case circuit breaker designed to deliver reliable branch circuit overcurrent and short-circuit protection for panelboards and load centers. With a robust 400A rating and a 600V maximum, this breaker is built to keep commercial, residential, and light industrial electrical systems safe and running smoothly.

why choose the Eaton KDB3400

• Space-efficient molded-case design minimizes panel footprint, making it easier to fit large protection capabilities into compact panelboards and load centers.
• Thermal‑magnetic trip unit provides stable, repeatable protection: the thermal element handles nuisance overloads, while the magnetic element delivers fast disconnection during short‑circuit events.
• 3-pole configuration ensures balanced protection across all phases, reducing the risk of unbalanced loads and unnecessary trips.
• 600V rating supports higher‑voltage electrical systems common in commercial and light industrial environments, with proven performance in demanding applications.
• 400A protection is ideal for main feeders or large branch circuits in panelboards, delivering solid protection where it matters most.
• OEM compatibility is designed to align with matching Eaton load centers and panelboards, offering straightforward installation and streamlined stocking.

Specifications at a glance

• 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
• Part number: KDB3400

Ideal uses and scenarios

Whether you’re upgrading a commercial panel, outfitting a light industrial service entrance, or expanding a residential system with higher protection needs, the KDB3400 shines when you require dependable discipline for large feeders and critical circuits. Its compact form helps you maximize space inside panelboards, while its reliable protection keeps equipment safe and uptime high in environments that demand consistent performance.

Practical integration tips

• Pair the KDB3400 with compatible Eaton OEM load centers and panelboards to maintain optimal coordination with adjacent protective devices.
• Operate within the 600V system specification to ensure safe, reliable performance across commercial and industrial installations.
• Consult Eaton installation guidelines during commissioning to confirm correct mounting, alignment, and any system-wide coordination requirements.