{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"XT1NU4125AFF000XXX","brand":"ABB","brandSlug":"abb","productSlug":"XT1NU4125AFF000XXX","canonicalUrl":"https://aoctrl.com/abb/XT1NU4125AFF000XXX","factsUrl":"https://aoctrl.com/api/mcp/products/XT1NU4125AFF000XXX","rawCanonicalId":null},"summary":{"shortDescription":"ABB XT1N 125 molded case circuit breaker, TMF 125-1250 trip unit, 125 A frame, 4-pole, front-front terminals, UL/CSA certified.","salesMarkdown":"## MCCB for panel builders — XT1N 125 frame with TMF trip The ABB XT1NU4125AFF000XXX is a 4-pole XT1N 125 molded case circuit breaker with a TMF 125-1250 thermal-magnetic trip unit, front-front terminals, and UL/CSA certification. The 125 A frame and TMF trip give you adjustable thermal pickup and fixed magnetic short-circuit protection — a standard choice for feeder and branch-circuit protection in 480 V distribution panels. ## What the TMF trip means for your coordination study The TMF 125-1250 trip unit gives you a thermal adjustment range from 125 A to 1250 A (the frame rating sets the upper bound at 125 A continuous) and a fixed magnetic pickup. That thermal adjustability lets you fine-tune the breaker to the actual load current without swapping trip units — useful when the connected load isn't exactly at the frame rating. The fixed magnetic short-circuit protection means the instantaneous trip point is set at the factory and cannot be changed in the field, which simplifies coordination with downstream devices. ## Panel integration — 4-pole, front-front terminals Four-pole configuration covers three-phase plus neutral switching, common in North American distribution panels where the neutral is switched for service disconnection. Front-front terminals mean line and load connections are both on the front face — this simplifies bus-bar routing and reduces the depth required inside the enclosure. The XT1N 125 frame size fits standard MCCB mounting footprints; no special adapters needed for most panelboards.","metaTitle":"ABB XT1NU4125AFF000XXX XT1N 125 TMF 125-1250 4P F F UL/CSA","metaDescription":"ABB XT1NU4125AFF000XXX XT1N 125 molded case circuit breaker, 125 A frame, TMF 125-1250 trip unit, 4-pole, UL/CSA. Lifecycle stage current. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Molded Case Circuit Breakers (MCCB)"],"specifications":{"title":"XT1NU4125AFF000XXX","description":"XT1N 125 TMF 125-1250 4P F F UL/CSA|XT1N 125 TMF 125-1250 4P F F UL/CSA","lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/98b2edbb21ca4a23bdea2c8f5eebdac7.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the closest alternative to XT1NU4125AFF000XXX in the XT1 family?","answer":"Within the XT1N 125 frame, the primary difference between variants is the trip unit type (TMF vs. TMD) and the terminal configuration (front-front vs. extended). The TMF trip offers adjustable thermal protection with fixed magnetic pickup, while the TMD trip has fixed thermal and magnetic settings. For a pin-compatible drop-in with the same 4-pole, front-front layout, look for another XT1N 125 order code with the same terminal style and the trip curve that matches your coordination study."},{"question":"Where can I buy XT1NU4125AFF000XXX?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/abb/XT1NU4125AFF000XXX","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/abb/XT1NU4125AFF000XXX when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}