Eaton HKD3125Y - 125 A, 600 V, 3-Pole Circuit Breaker | AmpState

Meet the Eaton HKD3125Y — a rugged 125A, 600V, 3-pole molded case circuit breaker designed to protect your electrical system with precision while maximizing panel space. Engineered for dependable branch circuit overcurrent and short‑circuit protection, it’s built to perform in real-world panelboards and loadcenters across residential, commercial, and light industrial environments.

• Compact molded case design optimizes interior space in panelboards, helping you fit reliable protection without crowding the enclosure.
• Thermal-magnetic trip unit delivers stable, repeatable protection by reacting to both overloads and short circuits with consistent timing and accuracy.
• 125A, 600V, 3-pole configuration supports three-phase distribution and higher-current branches, making it suitable for larger equipment circuits.
• OEM-compatible designed to pair with Eaton‑brand and compatible OEM loadcenters and panelboards for a seamless, trustworthy installation.
• Versatile application ideal for residential service enhancements, commercial panel protection, and light industrial distribution needs.

Key specifications

• Manufacturer: Eaton
• Part Number: HKD3125Y
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 125 A
• Voltage Rating: 600 V
• Number of Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Who this is for

The HKD3125Y is ideal for electrical installers and facility managers who need reliable, space-efficient protection for three‑phase circuits and sizable branch feeders. If you’re upgrading a panel to better safeguard critical equipment, or replacing a worn breaker in a commercial or light industrial setting, this unit delivers consistent performance and easy integration with compatible panel systems.

What problems it solves

• Prevents nuisance trips by offering a stable, predictable trip behavior for overloads and short circuits.
• Conserves panel space without sacrificing protection, thanks to its compact molded case design.
• Ensures compatibility and streamlined installation in OEM‑matched loadcenters, reducing configuration issues.
• Provides robust protection for three‑phase distribution networks commonly found in commercial or light industrial applications.

Practical tips for use

• Verify the panel compatibility: ensure the HKD3125Y is suitable for your specific Eaton or OEM loadcenter to guarantee a clean fit and reliable operation.
• Match protection to conductors: use within its 125 A rating for feeders and branch circuits that align with conductor sizes and enclosure capabilities.
• Consider three-phase requirements: the 3-pole design is ideal for protected three‑phase loads or equipment fed from a 3‑phase service.
• Follow standard electrical practices: install per manufacturer guidelines, maintain proper torque on lugs, and observe enclosure spacing for heat dissipation.