Federal Pacific NA50 Miniature Circuit Breaker

The NA series features a standard 1 inch per pole width, while the NC series has a thin half inch per pole design to save space in the panel. You must verify which width your specific Stab-Lok load center requires before installing.

Yes. Because original Federal Pacific breakers are obsolete, aftermarket manufacturers like Connecticut Electric produce direct replacements. The UBIF50N is a common aftermarket substitute designed to fit the same Stab-Lok load centers.

Yes. Federal Pacific Electric Stab-Lok panels and breakers have documented safety issues, including a higher rate of failing to trip during overcurrent or short circuit events. Many electrical professionals recommend upgrading the entire panel when possible.

You should always use the torque specification printed directly on the breaker label or the load center documentation. If the original label is missing or illegible, you must use the default torque values provided in NEC Table 110.14(D)(1) and UL 486A-486B based on your wire size.

No. This breaker features a proprietary Stab-Lok plug-on design that is exclusively compatible with legacy Federal Pacific load centers. It will not fit or function safely in modern panels from other manufacturers.

No. The original Federal Pacific Electric Company is no longer in business, and their original breakers are obsolete. Any original NA50 breakers available today are sourced from existing legacy stock or reclaimed inventory.

You must check the breaker label for an AL/CU or CU/AL designation. If it is marked for aluminum, you can use it with properly sized aluminum conductors. Always apply an approved oxide inhibiting joint compound when terminating aluminum wire.

Standard molded case circuit breakers are typically rated for continuous loads up to 80 percent of their maximum amperage. For a 50 amp breaker, the continuous load should not exceed 40 amps unless the breaker and enclosure are explicitly marked for 100 percent continuous operation.

The Stab-Lok system uses a unique plug-on design where the breaker terminals stab directly into the busbar slots of the load center. This allows for quick installation without the need for bolted connections, but it requires a compatible Federal Pacific enclosure.