{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"C166TM125C","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"C166TM125C","canonicalUrl":"https://aoctrl.com/schneider/C166TM125C","factsUrl":"https://aoctrl.com/api/mcp/products/C166TM125C","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric ComPacT NSX, TM-D trip unit, thermal-magnetic, 125 A at 50 °C, 4 poles 3D, LI protection.","salesMarkdown":"The C166TM125C is a thermal-magnetic trip unit from the Schneider Electric ComPacT NSX100...250 range, designed for fixed-mount circuit breakers in distribution applications. It carries a 125 A rating at 50 °C and complies with EN/IEC 60947-2, the standard that governs low-voltage switchgear and controlgear — so it meets the breaking, coordination, and insulation requirements for industrial panel builds. The TM-D unit provides LI protection: a thermal (L) element for overloads and a magnetic (I) element for short-circuits. The long-time pick-up Ir is adjustable from 0.7 to 1 x In, and the instantaneous pick-up Ii is fixed at 1250 A — meaning it will trip magnetically at ten times the rated current, which gives good selectivity with downstream breakers on a motor or distribution feeder. ## Deployment context This trip unit snaps into a ComPacT NSX100...250 circuit breaker frame. The 4-pole 3D configuration protects three phases with no neutral protection.","metaTitle":"C166TM125C ComPacT NSX TM-D Trip Unit, 125 A, 4P 3D","metaDescription":"C166TM125C thermal-magnetic trip unit for ComPacT NSX160/250. 125 A at 50 °C, EN/IEC 60947-2, LI protection. Active production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Miniature Circuit Breakers (MCB)"],"specifications":{"Range":"ComPacT","title":"C166TM125C","Standards":"EN/IEC 60947-2","description":"Trip unit TM125D, ComPacT NSX160/250, thermal magnetic, rating 125A, 50 degrees C, 4 poles 3D","Network type":"AC DC","Trip unit name":"TM-D","Protection type":"L : for overload protection (thermal) I : for short-circuit protection (magnetic)","lifecycle_stage":"current","Neutral position":"Left","Pollution degree":"3 conforming to IEC 60947-1","Range of product":"ComPacT NSX100...250","Trip unit rating":"125 A at 50 °C","Network frequency":"50/60 Hz","Poles description":"4P","Device application":"Distribution","Trip unit technology":"Thermal-magnetic","IP degree of protection":"IP40 conforming to IEC 60529","Earth-leakage protection":"Without","Product or component type":"Trip unit","Neutral protection settings":"No protection (3D)","Protected poles description":"3D","Circuit breaker mounting mode":"Fixed","Trip unit protection functions":"LI","[Ue] rated operational voltage":"690 V AC 50/60 Hz 750 V DC","Electrical shock protection class":"Class II","Ambient air temperature for storage":"-50...85 °C","Ambient air temperature for operation":"-25...70 °C","Long-time protection delay adjustment type tr":"Fixed","[Tr] Long-Time Protection Delay Adjustment Range":"120...400 s at 1.5 x In 15 s at 6 x Ir","[Ir] long-time protection pick-up adjustment range":"0.7...1 x In","Instantaneous protection pick-up adjustment type Ii":"Fixed","[Ii] instantaneous protection pick-up adjustment range":"1250 A","Long-time pick-up adjustment type Ir (thermal protection)":"Adjustable"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/17f707f468070da20b8c1fbf0ab35b62.pdf","sourceUrl":"https://www.se.com/vn/en/product/C166TM125C/trip-unit-tm125d-compact-nsx160-250-thermal-magnetic-rating-125a-50-degrees-c-4-poles-3d/"},"ai":{"faq":[{"question":"What is C166TM125C's listed range and standards?","answer":"It belongs to the Schneider Electric ComPacT NSX100...250 range and complies with EN/IEC 60947-2, the standard for low-voltage switchgear and controlgear."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/C166TM125C","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/schneider/C166TM125C when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}