The ABB TEY345ST12 is a compact, one-inch wide per pole circuit breaker designed for grounded 480Y/277 Vac systems. This bolt-on style breaker is versatile enough for different setups, especially when used as a lug-to-lug breaker with its mounting base accessory. Known for its Quick-make / Quick-break mechanism and common trip bars, the TEY series offers reliable performance and clear trip indication for easy troubleshooting. Available in 1, 2, and 3 pole options, these breakers can also be fitted with auxiliary contacts and shunt trip accessories for added functionality. Distributed by BSP Automation, the TEY345ST12 is a solid, no-nonsense choice for protecting your electrical circuits. You might hear folks call it the “go-to” MCCB for medium-duty industrial applications.