Eaton / Cutler-Hammer FB3100PL Molded Case Circuit Breaker

This F-frame breaker is primarily used in legacy Westinghouse and Eaton switchboards, as well as motor control centers. It is a unit mount breaker, meaning it bolts directly to the mounting pan or chassis rather than plugging into a panelboard bus.

Current limiting breakers like this model clear short circuits in less than half a cycle. This drastically reduces the peak let-through current and energy, protecting downstream equipment from severe thermal and magnetic stress during a fault. This capability allows it to achieve a massive 200kAIC rating at 600VAC.

The factory lugs accept wire gauges from 14 AWG up to 1/0 AWG. The terminals are rated for both copper and aluminum conductors. Ensure you torque the lugs to the manufacturer specifications printed on the breaker faceplate during installation.

Yes. Eaton acquired the Cutler-Hammer and Westinghouse electrical distribution lines. A modern Eaton FB3100PL is the exact direct replacement for legacy Westinghouse or Cutler-Hammer breakers with the same catalog number.

No, the FB3100PL features a fixed thermal and fixed magnetic trip unit. The long time and instantaneous trip functions are factory set for 100 amps and cannot be adjusted in the field.

A feed-thru connection means the breaker has lugs on both the line and load sides. Power cables are wired directly into the top and bottom terminals, rather than the breaker connecting directly to a live panelboard busbar.

Yes, this breaker is rated for use in DC systems up to 250VDC, where it provides an interrupting capacity of 100kAIC. When wiring for DC applications, consult the manufacturer wiring diagrams to ensure the poles are connected in the correct series configuration.