FA14040B SQUARE D 1P 40A 277V B PH I LINE

The FA14040B is rated 1-pole, 40 amps, 277 volts, with an 18kA interrupt capacity. Its 277V rating makes it particularly well-suited for commercial single-phase branch circuits — most commonly 277V fluorescent or LED lighting loads fed from a 480Y/277V three-phase distribution system.

Square D's FA-frame lineup has seen transitions over the years, and some variants can be difficult to find through standard channels. Northern Breaker Group specializes in obsolete and hard-to-find breakers — contact us for current availability and we'll provide a quote.

Replacement breakers must match the original frame, voltage rating, amperage, interrupt rating, and plug-in mounting configuration to ensure safe, code-compliant installation. Substituting a different frame or brand is generally not recommended without verifying compatibility with the panelboard manufacturer. Contact our team and we'll help identify a correct direct replacement or approved equivalent.