{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"C2544B250","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"C2544B250","canonicalUrl":"https://aoctrl.com/schneider/C2544B250","factsUrl":"https://aoctrl.com/api/mcp/products/C2544B250","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric ComPacT NSX250, MicroLogic 4.2 AB electronic trip unit, 250 A at 40 °C, 4P, LSoIR + earth-leakage protection.","salesMarkdown":"The Schneider Electric C2544B250 is a MicroLogic 4.2 AB electronic trip unit for the ComPacT NSX100...250 range of molded-case circuit breakers. It is the programmable brain that sits inside the breaker frame, measuring current and deciding when to trip based on the protection curves you set. This is a 4-pole unit (4P) rated at 250 A at 40 °C, designed for AC networks at 50/60 Hz with a rated operational voltage of 440 V AC. The trip unit provides LSoIR protection: L for long-time overload, So for short-time short-circuit with a fixed delay, I for instantaneous short-circuit, and R for earth-leakage. The earth-leakage protection is integrated and Class A, with adjustable sensitivity (IΔn) and time delay (Δt). This makes the unit suitable for special applications requiring both overcurrent and ground-fault protection in a single device. The long-time pick-up (Ir) is adjustable from 140 to 240 A, so you can fine-tune the overload threshold to match the downstream load without swapping the trip unit. The short-time pick-up (Isd) adjusts from 1.5 to 10 times Ir, giving you selectivity coordination with downstream breakers — a key parameter for panel builders designing a coordinated distribution system per IEC 60947-2. The instantaneous pick-up is fixed at 2880 A — that is the magnetic-only trip level for bolted faults. This matters for motor-starting applications where repeated starts can overheat the circuit. This trip unit mounts into a ComPacT NSX250 fixed-mount breaker frame. The neutral position is left, and the protected poles can be configured as 3D + N/2, 4D, or 3D — meaning you can set the neutral protection to half the phase current, full current, or none, depending on the system grounding. The local signaling includes a flashing green LED for ready, red LED at 105% Ir for overload, orange at 90% Ir for pre-alarm, and a yellow indicator for residual current. These are visible through the breaker's transparent cover for quick status checks without opening the panel.","metaTitle":"Schneider C2544B250 MicroLogic 4.2 AB Trip Unit, 250 A, 4P","metaDescription":"Schneider Electric C2544B250 MicroLogic 4.2 AB electronic trip unit for ComPacT NSX250. 250 A at 40 °C, 4P, LSoIR protection with integrated earth-leakage. EN/IEC 60947-2. Current","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Residual Current Breakers (RCCB/RCBO)"],"specifications":{"Range":"ComPacT","Standards":"EN/IEC 60947-2","Network type":"AC","Thermal memory":"20 minutes before and after tripping","Trip unit name":"MicroLogic 4.2 AB","Protection type":"L : for overload protection (long time) So : for short time short-circuit protection with fixed delay I : for instantaneous short-circuit protection R : for earth-leakage protection","lifecycle_stage":"current","Local signalling":"Flashing LED (green) for ready to operate LED 105 % Ir (red) for overload LED 90 % Ir (orange) for overload Color indicator (yellow) for residual current","Neutral position":"Left","Pollution degree":"3 conforming to IEC 60947-1","Range of product":"ComPacT NSX100...250","Trip unit rating":"250 A at 40 °C","Network frequency":"50/60 Hz","Poles description":"4P","Device application":"Special application","Trip unit technology":"Electronic","IP degree of protection":"IP40 conforming to IEC 60529","Earth-leakage protection":"Integrated","Product or component type":"Trip unit","Neutral protection settings":"0.5 x Ir (3D + N/2) 1 x Ir (4D) No protection (3D)","Protected poles description":"3D + N/2 4D 3D","Circuit breaker mounting mode":"Fixed","Earth-leakage protection class":"Class A","Trip unit protection functions":"LSoIR","[Ue] rated operational voltage":"440 V AC 50/60 Hz","Zone selective interlocking ZSI":"Without","Electrical shock protection class":"Class II","Ambient air temperature for storage":"-40...85 °C","Ambient air temperature for operation":"-25...70 °C","Earth-leakage protection specific mode":"OFF using the IΔn rotary switch","Long-time protection delay adjustment type tr":"Fixed","Short-time protection delay adjustment type tsd":"Fixed","[Tr] Long-Time Protection Delay Adjustment Range":"0.35 s at 7.2 x Ir 0.5 s at 6 x Ir 15 s at 1.5 x Ir","Short-time protection pick-up adjustment type Isd":"Adjustable","[Ir] long-time protection pick-up adjustment range":"140...240 A","Instantaneous protection pick-up adjustment type Ii":"Fixed","[Isd] Short-time protection pick-up adjustment range":"1.5...10 x Ir","[Ii] instantaneous protection pick-up adjustment range":"2880 A","Earth-leakage protection sensitity adjustment type IΔn":"Adjustable","Earth-leakage protection time delay adjustement type Δt":"Adjustable","Long-time pick-up adjustment type Ir (thermal protection)":"Adjustable","[Δt] Earth-leakage protection time delay adjustment range":"0 ms 60 ms 150 ms 500 ms 1 s","[IΔn] earth-leakage protection sensitivity adjustment range":"0.03 A 0.1 A 0.3 A 0.5 A 1 A 3 A 5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d083ad2e7b2ee3e123fb9baa8b4e4e7f.pdf","sourceUrl":"https://www.se.com/hk/en/product/C2544B250/trip-unit-micrologic-vigi-4-2ab-compact-nsx250-4p-basic-and-earth-leakage-protections-special-applications-240a/","alternativesUrl":"https://aoctrl.com/api/mcp/products/C2544B250/alternatives.json"},"ai":{"faq":[{"question":"How do I get current pricing and availability for C2544B250?","answer":"The C2544B250 is sourced and quoted to order against an RFQ through independent distribution. Current pricing and availability are confirmed at quote time."},{"question":"What are the key protection settings on the C2544B250?","answer":"The MicroLogic 4.2 AB provides LSoIR protection: long-time overload (Ir adjustable 140-240 A), short-time short-circuit (Isd adjustable 1.5-10 x Ir with fixed delay), instantaneous short-circuit (Ii fixed at 2880 A), and integrated earth-leakage (Class A, adjustable sensitivity and time delay)."},{"question":"What standards does the C2544B250 comply with?","answer":"The C2544B250 complies with EN/IEC 60947-2, the standard for low-voltage switchgear and controlgear circuit-breakers. It also carries pollution degree 3 per IEC 60947-1 and IP40 per IEC 60529."},{"question":"What is the C2544B250's operating temperature range?","answer":"The operating ambient temperature range is -25 to 70 °C, with storage from -40 to 85 °C. The 250 A rating is at 40 °C; derating may apply at higher ambients."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/C2544B250","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/C2544B250 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}