The ABB XT1NU3015AAA000XXX is a 15 A, 3-pole molded case circuit breaker from the Tmax XT series, rated for 600 VAC and delivering a 25 kA interrupting capacity at 480 VAC. The 15 A continuous rating means it protects a branch circuit or load drawing up to that current — sized for a motor, a control transformer, or a lighting panel on a 480Y/277 V system. Panel-mount construction means it bolts into a switchboard or distribution panel — not a DIN-rail snap-in. Verify the mounting footprint against your existing bus or backplate before ordering.
Integration note for the panel builder
Panel-mount breaker means you need clearance for the arc chute exhaust and enough finger-duct space for the load-side conductors. The Tmax XT frame is compact for a 600 V class MCCB — check the ABB dimensional drawing for the exact cutout and bus-bar spacing before laying out the backplate.