{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451.500NRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451.500NRL","canonicalUrl":"https://icboms.com/littelfuse-inc/0451.500NRL","factsUrl":"https://icboms.com/api/mcp/products/0451.500NRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, Board Mount (Cartridge Style Excluded) fuse, 0451.500NRL, 500 mA, 125 V AC/DC, Fast Blow, 50 A breaking capacity, Surface Mount, 2-SMD Square End Block package.","salesMarkdown":"## Active production — what it means for your BOM line The 0451.500NRL: This is a 500 mA fast-blow fuse in the NANO²® 451 series, rated for 125 V on both AC and DC circuits. ## Breaking capacity and I²t — the real protection envelope Rated breaking capacity is 50 A at the rated voltage — meaning the fuse can safely interrupt a fault current up to 50 A without rupturing or sustaining an arc. For a 500 mA rail, that is 100× the load current, giving solid margin against a dead short. Melting I²t is 0.0795 A²s — this is the energy needed to clear the fuse element. In a circuit with inrush, the I²t of the surge must stay below this value to avoid nuisance opens. A 500 mA fast-blow with this I²t handles moderate capacitive inrush on a small DC-DC input or a low-power sensor node. The operating temperature range spans -55°C to 125°C, so it works in an engine-bay ECU or a cold-chain logger without derating the current at the extremes. ## Package and board-fit for hand-assembly Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm — the end-cap terminations are large enough for hand-soldering with a fine tip, and the square body sits flat on the pad without tombstoning during reflow. ## Approvals and compliance for global shipping Listed with CSA and UL approvals — the fuse is accepted in North American and Canadian equipment without a separate agency review. The NANO²® 451 series is a board-mount fuse (cartridge style excluded), so it is designed for direct soldering onto a PCB rather than a panel-mount holder.","metaTitle":"0451.500NRL Littelfuse NANO² 451 Fuse, 500 mA, 125 V","metaDescription":"0451.500NRL Littelfuse NANO² 451 surface-mount fuse, 500 mA, 125 V AC/DC, fast blow, 50 A breaking capacity, CSA/UL approved. Active lifecycle.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Color":"-","Series":"NANO²® 451","Package":"Tape & Reel (TR); Cut Tape (CT)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"0.0795","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","Approval Agency":"CSA, UL","lifecycle_stage":"unknown","Size / Dimension":"0.240\\\" L x 0.106\\\" W x 0.106\\\" H (6.10mm x 2.69mm x 2.69mm)","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"500 mA","Operating Temperature":"-55°C~125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4600","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is 0451.500NRL's breaking capacity and why does it matter?","answer":"The breaking capacity is 50 A at the rated voltage. This means the fuse can safely clear a fault current up to 50 A without exploding or sustaining an arc — critical for protecting downstream components in a short-circuit event."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451.500NRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451.500NRL when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}