The ABB XT1NU3040AAA0A0XXX is a Tmax XT1 molded case circuit breaker rated 40 A continuous, 3-pole, with a 600Y/347 VAC maximum voltage and an interrupting capacity of 18 kAIC. Panel-mounted with front flat terminals for straightforward bus or cable connections in a distribution panel.
Ratings and application context
The 40 A rating on the XT1N frame means this breaker is sized for feeder or branch circuits drawing up to that continuous current. The 600Y/347 VAC rating confirms suitability for 480Y/277 V wye systems, common in North American lighting and distribution panels. Thermal-magnetic trip gives you a fixed thermal element for overload protection and a magnetic element for short-circuit response — no adjustment, no calibration drift over time. For a panel OEM or MRO planner, that means one less variable in the coordination study.