Eaton / Cutler-Hammer KDC3400 Molded Case Circuit Breaker

While all three are 400A, 3-pole Series C K-frame breakers that share the same physical dimensions and accessories, they have different interrupting capacities. The KD series is standard (35kAIC at 480V), the HKD series is high (65kAIC at 480V), and the KDC features an ultra-high interrupting rating of 100kAIC at 480V. The KDC3400 can directly replace a KD3400 or HKD3400 when a higher fault current rating is required.

The ultra-high interrupting capacity of the KDC series is required in industrial plants, large commercial facilities, or heavy-duty motor control centers situated close to large utility transformers. In these locations, the available fault current often exceeds the limits of standard commercial breakers.

This breaker features a fixed thermal and adjustable magnetic trip unit. The instantaneous magnetic trip threshold can be adjusted, typically between 5 and 10 times the 400A continuous rating, using the flathead adjustment dials on the front of the trip unit. This allows for precise coordination with motor inrush currents and downstream devices.

No. The standard factory lugs provided with this breaker are designed to accept two conductors per phase, ranging from 3/0 AWG to 250 kcmil. If your application requires a single large conductor, you must replace the standard dual-barrel lugs with a compatible Eaton K-frame single-wire lug kit.

Yes. Eaton Series C thermal magnetic breakers without specialized electronic trip limitations are suitable for reverse feed applications. When reverse feeding, properly label the equipment and verify zero voltage on all terminals before maintenance, as traditional line and load orientations will not apply.

This feed-thru panel mount breaker is designed for installation in Eaton and Cutler-Hammer Series C panelboards, switchboards, and motor control centers. It requires K-frame mounting hardware and bus connections specific to the enclosure type.

Only licensed electrical professionals should install or service this equipment. Ensure all line and load side power sources are de-energized, locked out, and tagged out. Verify zero voltage with a calibrated multimeter, paying special attention to interconnected or reverse-feed setups where the load terminals may still be energized.