Eaton DK3400 - 400 A, 240 V, 3-Pole Circuit Breaker | AmpState

Eaton DK3400 — a rugged 400 A, 240 V, 3-pole molded case circuit breaker designed for dependable protection in panelboards and loadcenters. This device is built to guard you against overcurrent and short-circuit conditions across residential, commercial, and light industrial applications, delivering peace of mind where it matters most.

Engineered for practical, real-world use, the DK3400 combines a compact molded case design with a reliable thermal-magnetic trip unit. This pairing provides stable, repeatable protection performance, reacting intelligently to both prolonged overloads and instantaneous fault currents. The result is consistent protection that you can depend on, even in busy electrical environments.

Key advantages that set this breaker apart

• Space-efficient molded case design: Optimizes panel layout, freeing up valuable space in switchgear and reducing installation complexity.
• Thermal-magnetic trip unit: Offers reliable, predictable protection by addressing both overload and short-circuit conditions without nuisance tripping.
• OEM-panel compatibility: Designed to pair with matching Eaton OEM loadcenters and panelboards for streamlined replacement and upgrade projects.
• Versatile across environments: Suitable for residential, commercial, and light industrial electrical setups where dependable branch circuit protection is essential.

Technical snapshot

• Manufacturer: Eaton
• Part number: DK3400
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 400 A
• Voltage rating: 240 V
• Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases and practical benefits

The DK3400 is an excellent choice when you need robust protection for feeder circuits feeding multiple branch circuits inside a panelboard, or as part of a modernization project where you want to maintain a cohesive OEM protection family. It’s particularly well-suited for installations that require:

• Main or feeder protection in service panels and distribution panels within light commercial spaces
• Upgrades or replacements in existing Eaton-powered installations to maintain full system coordination
• Reliable protection for motor-driven loads where inrush and fault currents must be managed safely

How this compares to alternatives (without naming competitors)

With its molded case construction and a thermal-magnetic trip mechanism, the DK3400 offers a compact, plug-compatible solution that emphasizes panel space efficiency and predictable protection. When you’re updating or expanding an Eaton-based electrical system, choosing the DK3400 helps preserve system coordination, simplifies ordering with a like-for-like part, and minimizes modification requirements in the panel enclosure. The result is a cleaner, faster installation with protection you can trust across a range of light industrial and commercial environments.

Tips for installation and optimal performance

• Verify compatibility with the existing OEM loadcenter or panelboard family before replacement to ensure seamless operation and coordination.
• Install using proper torque on mounting and lugs as specified for molded case breakers to maintain reliable electrical contact.
• Coordinate protection levels within the panel by pairing the DK3400 with other Eaton protection devices designed for the same system to optimize overall reliability.
• When planning a retrofit or expansion, consider the DK3400’s space-saving footprint to maximize panel efficiency and reduce wiring congestion.

Choose the Eaton DK3400 when you need a dependable, space-conscious solution for 400 A, 240 V, 3-pole protection that integrates smoothly with Eaton panelboards and loadcenters, delivering consistent performance for years of service.