Eaton Cutler-Hammer 3T402K 400A 3P Circuit Breaker | AmpState

The Eaton Cutler-Hammer 3T402K 400A 3P circuit breaker is built for dependable, everyday electrical protection in panelboards, load centers, and distribution networks. Designed for three-phase systems, this 3-pole breaker helps safeguard critical equipment and power distribution with precision and reliability.

• Amperage: 400 A
• Poles: 3 (3P)
• Part number: 3T402K
• Manufacturer: Eaton Cutler-Hammer
• Type: Circuit Breaker

Key differentiators — this 3T402K model is purpose-built to align with Eaton’s original BOM, making it the go-to choice for replacement projects where compatibility with existing gear matters most. By maintaining BOM fidelity, you reduce installation guesswork and stay consistent with your electrical distribution design.

Ideal for replacements and stock management — when a 400A, three-pole unit fails or reaches end-of-life, this breaker slots into compatible Eaton panelboards and load centers without forcing a redesign. It’s also an excellent spare to keep on hand to minimize downtime during maintenance windows.

Practical use cases:

• Replacing a worn or damaged 3P 400A breaker in commercial or industrial panels
• Maintaining BOM integrity by using the exact original part number in upgrades or repairs
• Ensuring consistent three-phase protection for electrical distribution networks

Available from AmpState, the 3T402K is ready to support your electrical distribution needs. If you’re unsure about compatibility or the exact match for your panel, send us a message and we’ll help confirm fit and ensure you choose the right Eaton Cutler-Hammer breaker for your system.