21-D166TJK | Circuit Breaker | 400A | 600V

Meet the 21-D166TJK industrial circuit breaker—an essential protective device for demanding electrical installations. With a 400A current rating and a 600V operating window, this breaker is engineered to safeguard heavy power circuits, motor feeders, and critical equipment from overloads and electrical faults while keeping downtime to a minimum.

Why this model matters — this isn’t a generic replacement. The 21-D166TJK is designed to align with specific panels, enclosures, and switchgear when exact specs are required. The part number is the most reliable reference for compatibility, helping you avoid mismatches and unnecessary service interruptions.

Key specifications

• Amperage: 400A
• Voltage: 600V

Ideal use cases

• Maintenance and retrofit projects where you need a precise fit without reconfiguring wiring or bus connections.
• Replacement in industrial power distributions serving conveyors, pumps, drive systems, and other high-load equipment.
• Upgrades that require consistent protection characteristics within an existing protection scheme.

Practical guidance for procurement

• Always confirm fit and ratings before ordering. The 21-D166TJK is the best reference for compatibility with your existing equipment.
• Have the current panel or enclosure documentation on hand to verify mounting style and electrical compatibility.
• Record the part number for future maintenance so replacements can be sourced quickly and accurately.

Choosing the 21-D166TJK means committing to reliable circuit protection that supports steady operations, protects valuable assets, and simplifies maintenance planning in industrial environments. If your system operates at 400A and 600V, this specific breaker is designed to slot into place where compatibility is required, delivering dependable performance when it matters most.