Square D FCL34015 Molded Case Circuit Breaker

The FCL34015 is a legacy F-frame breaker and is no longer in active production. For new installations or direct replacements, the Square D PowerPact H-frame series, specifically the HJL36015, is the modern equivalent.

As a current limiting breaker, the FCL34015 is designed to clear severe faults in less than one millisecond. This rapid response restricts the let-through energy, protecting sensitive downstream equipment from high short-circuit currents.

No. The FCL34015 is a unit-mount, feed-thru circuit breaker designed for standard enclosures, switchboards, and motor control centers. It does not have the plug-on jaw connections required for I-Line panelboards.

This is a unit-mount circuit breaker, meaning it is bolted directly to the backpan or mounting plate of a standard Square D enclosure or motor control center, rather than plugging directly onto a busbar.

No. The FCL34015 features a standard thermal-magnetic trip unit with Long-Time and Instantaneous (LI) trip functions. It provides overload and short-circuit protection but does not include integrated ground fault capabilities.

By utilizing current limiting technology, this breaker forces its contacts open using electromagnetic repulsion before the fault current reaches its peak. This significantly reduces thermal and mechanical stress on the electrical distribution system.

No. This breaker features fixed thermal and fixed magnetic trip elements. The Long-Time and Instantaneous trip thresholds are factory set and cannot be adjusted in the field.