Designed for commercial and industrial applications, the KDB3400 is a 3-pole, 400A molded case circuit breaker from Eaton's Series C family. It provides robust overcurrent and short-circuit protection for heavy-duty electrical systems. This K-Frame device installs into compatible Eaton panelboards, switchboards, and motor control centers. It features a standard panel mount configuration and includes line and load lugs for straightforward wire termination.
What is the difference between the Eaton KD3400 and KDB3400?
The KDB3400 is a complete, factory-assembled circuit breaker that includes the K-frame, a fixed thermal-magnetic trip unit, and standard line and load terminals. The KD3400 catalog number is often used interchangeably, but the 'B' specifically designates that the standard line and load lugs are included from the factory.
Can the KDB3400 circuit breaker be reverse fed?
Yes. Eaton K-frame thermal-magnetic circuit breakers with fixed trip units are generally suitable for reverse feed applications because they do not have line and load markings. Always use the appropriate retaining bracket when backfeeding in a panel.
Are the trip settings on the KDB3400 adjustable?
No. This specific model features a fixed thermal and fixed magnetic trip unit. If you require adjustable trip settings, you will need to select an electronic trip unit or a different K-frame model with interchangeable trip capabilities.
What equipment is the KDB3400 designed to fit?
This 400A K-frame breaker is engineered for installation in Eaton Series C panelboards, motor control centers, and switchboards. It mounts directly to the panel using a standard feed-thru configuration.
Is the KDB3400 rated for direct current (DC) systems?
Yes, in addition to its alternating current ratings, this breaker is rated for use in 250VDC systems with a maximum interrupting capacity of 10kAIC.
What wire sizes are compatible with the standard lugs on this breaker?
The included line and load terminals are designed to accept two 3/0 AWG to 250 kcmil wires per phase. The lugs are rated for both aluminum and copper conductors.
What safety precautions are required before servicing or reverse feeding the KDB3400?
Always verify that the circuit breaker is switched to the OFF position and that no voltage is present on either the line or load side. Special attention is required in reverse feed applications, as the load terminals may remain energized even when the breaker is open.
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