Eaton / Westinghouse G3040 Molded Case Circuit Breaker

The G3040 is a Series C, G-frame bolt-on circuit breaker designed for use in legacy Westinghouse panelboards, switchboards, and motor control centers. It mounts directly to the chassis rail and bus connections.

Yes, the Eaton G3040 is a direct drop-in replacement for original Westinghouse G3040 breakers. Because Eaton acquired the Westinghouse distribution equipment line, these breakers share the same physical dimensions, bolt-on mounting, and thermal-magnetic trip characteristics as the legacy units.

For G-frame breakers like the G3040 using 14 to 10 AWG wire, the recommended terminal torque is 20 in-lb. For 8 AWG wire, apply 40 in-lb, and for 6 to 1/0 AWG wire, apply 45 in-lb. Always verify the exact torque specifications printed on the breaker nameplate before finalizing the installation.

Yes, the G3040 is rated for up to 250VDC with a 14kA interrupting capacity. When installing in DC systems, specific wiring configurations, such as wiring poles in series, may be required depending on the system voltage. Consult Eaton Series C application guidelines for proper DC wiring diagrams.

While the G3040 is primarily a bolt-on breaker for panelboards, it can be mounted to a standard 35mm DIN rail using a specific Eaton adapter kit. The adapter must be preassembled to the rear recess of the breaker before sliding it onto the rail.

Yes, when terminating aluminum wire to the lugs of the G3040, applying a suitable joint compound is highly recommended. This prevents oxidation and terminal overheating, which can lead to nuisance tripping or damage to the breaker.

When the breaker trips, the handle moves to a middle position, revealing a white strip. To restore power, you must first push the handle to the extreme OFF position to reset the internal mechanism, and then push it firmly to the ON position.