Eaton / Cutler-Hammer KB3250 Molded Case Circuit Breaker

Yes. The KB3250 maintains the original AB De-Ion K-Frame dimensions and bolt-on mounting configuration. It installs directly into legacy Westinghouse CDP panelboards and Eaton Series C panelboards without requiring bus modifications or retrofit kits.

Yes. Eaton acquired the Westinghouse distribution equipment division and continued manufacturing the same K-Frame breakers under the Cutler-Hammer and Eaton brands. They are physically and electrically identical and serve as exact drop-in replacements.

The HKB3250 is the high-interrupting capacity version of this breaker. It shares the same physical dimensions and K-Frame footprint but offers upgraded fault protection, including a 65kAIC rating at 240VAC and 25kAIC at 480VAC.

This breaker features a fixed thermal element for overload protection and an adjustable magnetic element for instantaneous short-circuit protection. The magnetic trip can be tuned between 1250A and 2500A, which is 5 to 10 times the 250A continuous rating, allowing for precise coordination with downstream devices.

The standard load-side lugs accept aluminum or copper wire ranging from 3 AWG to 350 kcmil. Ensure proper torque specifications are followed during installation to maintain a secure connection.

The KB3250 is a thermal-magnetic circuit breaker that provides both overcurrent and short-circuit protection. The KB3250N is a molded case switch used strictly as a disconnect. The KB3250N does not have an integrated trip unit and requires an upstream device for overcurrent protection.