125 A, 3-pole thermal-magnetic MCCB for 240 V distribution
The ABB A2N125TW is a 125 A, 3-pole molded case circuit breaker rated for 240 V AC/DC circuits, with a 25 kA interrupting capacity at 240 V. The thermal-magnetic trip unit provides overload protection via a bimetal element and short-circuit protection via a solenoid — no electronic trip board to fail or need programming. Panel-mount design fits standard distribution board cutouts; the A2 frame is the smallest ABB MCCB frame, saving space in a crowded panel. The 25 kAIC at 240 V means it can safely clear a bolted fault on a transformer secondary or a large feeder without requiring an upstream current-limiting fuse.
End-of-life sourcing — what the EOL-hot status means for your BOM
For a BOM freeze or a line-down replacement, the page's value is the cross-reference to available inventory. The 125 A, 3-pole, 240 V AC/DC rating and thermal-magnetic trip are the fit criteria — confirm the frame size (A2) and panel cutout match the existing installation before committing.
Panel integration — mounting and wiring checklist
Panel mount — the breaker bolts directly to the enclosure backplate or a mounting pan. No DIN rail adapter; plan for fixed lug connections. The A2 frame accepts line and load lugs up to the rated ampacity; verify the lug wire range against the existing conductor size. Three-pole configuration means it switches all three phases simultaneously — suitable for three-phase motor circuits, feeder protection, or as a main disconnect in a 240 V panel. The 240 V AC/DC rating covers both single-phase and three-phase 240 V systems, plus DC control circuits at the same voltage.