Square D FC34090 Molded Case Circuit Breaker

This breaker is specifically designed for Square D I-Line panelboards and switchboards. It will not fit in standard QO, NQ, or NF load centers because it requires the specialized I-Line busbar architecture.

The line side of the breaker features built-in spring jaws that push directly onto the panelboard bus, eliminating the need for line-side wiring or hardware. The load side uses standard mechanical lugs to terminate the branch circuit wires.

No, mechanical load lugs are included as standard equipment on this model. They are rated to accept 14 to 1/0 AWG copper wire or 12 to 1/0 AWG aluminum wire.

No. The thermal-magnetic trip unit is manufactured with fixed settings for both the long-time overload and instantaneous short-circuit functions.

The FC frame is considered a legacy F-frame product. For new installations or direct replacements, Schneider Electric currently manufactures the PowerPact H-frame series as the modern equivalent, which shares the same I-Line bus mounting dimensions.

Facilities located close to large utility transformers often have very high available fault currents. The 65kA rating ensures the breaker can safely clear massive short circuits up to 65,000 amps at 480VAC without rupturing, which protects downstream equipment and mitigates arc flash risks.