Eaton / Cutler-Hammer FS340050A Molded Case Circuit Breaker

This F-Frame breaker is designed for installation in Eaton Series C panelboards, switchboards, and motor control centers that accept unit-mount, feed-thru configurations.

It features a unit-mount, feed-thru design. Instead of plugging into a busbar, it is bolted directly to a mounting surface or enclosure backpan and hardwired on both the line and load sides.

The factory-installed lugs accept 14 AWG to 1/0 AWG wire and are rated for both copper (Cu) and aluminum (Al) conductors.

The LI code means the breaker uses a thermal-magnetic trip unit with Long-Time (L) overload protection and Instantaneous (I) short-circuit protection. Both the thermal and magnetic trip points are fixed and cannot be adjusted in the field.

Yes, the FS340050A is rated for DC applications up to 250VDC, where it provides a 10 kAIC interrupting rating.

Eaton Series C F-Frame breakers support various internal accessories, including shunt trips, auxiliary switches, and undervoltage releases. However, UL guidelines require these to be factory-installed, typically in the left pole, rather than field-installed.

Installing a breaker in a system where the available fault current exceeds its interrupting rating (14 kA at 480V or 22 kA at 240V) creates a severe safety hazard. The breaker may fail to clear a short circuit, risking catastrophic equipment failure or an arc flash.

Yes, Eaton Series C F-Frame breakers are the direct continuation of the legacy Cutler-Hammer and Westinghouse Series C lines. This model can replace older breakers from those brands that share the same physical dimensions, 50A rating, and unit-mount configuration.

As an Eaton Series C F-Frame 3-pole breaker, it features standardized dimensions of 6.00 inches in height, 4.13 inches in width, and 3.38 inches in depth.