{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"5TT5840-8","brand":"Siemens","brandSlug":"siemens","productSlug":"5TT5840-8","canonicalUrl":"https://aoctrl.com/siemens/5TT5840-8","factsUrl":"https://aoctrl.com/api/mcp/products/5TT5840-8","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON Insta contactor, 5TT5840-8, 4 NO contacts, 24 V AC coil, rated 400 V 40 A, 3 modular width units, IP20.","salesMarkdown":"The Siemens SENTRON 5TT5840-8 is an Insta contactor with 4 normally open contacts, designed for switching loads on 400 V AC circuits up to 40 A, with a 24 V AC control coil. The 24 V AC coil is standard for control transformers or PLC relay outputs; verify your control voltage is AC, not DC, because the coil is AC-rated only. Switching capacity for incandescent lamp loads is listed at 4 000 W, which is the figure to use when sizing for lighting circuits — the 40 A general rating is for resistive or motor loads, and lamp inrush current requires this derated power limit. The 4 NO contact configuration (zero NC) means this contactor is a make-only device — it closes all four poles when the coil is energized. If your circuit needs a normally closed auxiliary for status feedback or interlocking, you will need an add-on auxiliary contact block; the product extension slot supports supplementary devices. ## Installation and panel integration IP20 protection class means it is suitable for dry indoor panels only — no washdown, no outdoor exposure without an additional enclosure. Power loss is 4 W per pole in hot operating state at rated AC current. In a multi-contactor panel, sum these losses to check your enclosure thermal budget; four contactors at full load add 64 W of heat.","metaTitle":"Siemens 5TT5840-8 SENTRON Insta Contactor, 4 NO, 24 VAC, 400","metaDescription":"Siemens SENTRON 5TT5840-8 Insta contactor with 4 NO contacts, 24 VAC coil, rated 400V 40A. Active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"Depth":"71 mm","Width":"54 mm","title":"5TT5840-8","Height":"90 mm","Maximum":"440 V","Minimum":"440 V","Rated Value":"24 V","description":"INSTA contactor 0/1-automatic with 4 NO contacts Contact for 230 V AC, 400V 40A Control 24 V AC","lifecycle_stage":"current","Installation Depth":"0 mm","Product Brand Name":"SENTRON","Product Designation":"Insta contactor","Rated Value Maximum":"24 V","protection class IP":"IP20","Design Of The Product":"4 NO contacts","number of NC contacts":"0","number of NO contacts":"4","Installation Or Assembly Note":"provision must be made for spacers to ensure heat dissipation","Number Of Modular Width Units":"3","Type Of Voltage Of The Operating Voltage":"AC","Product Extension Installable Supplementary Devices":"Yes","Type Of Voltage Of The Operating Voltage For Actuation":"AC","Switching Capacity Active Power With Incandescent Lamp Load":"4 000 W","power loss [W] for rated value of the current at AC in hot operating state per pole":"4 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/954c8e346fa6f0955fbf08abef4fe7a8.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=507977&mlfb=5TT5840-8"},"ai":{"faq":[{"question":"What are the key ratings of 5TT5840-8?","answer":"The contactor is rated 400 V 40 A on the main contacts, with a 24 V AC coil. It has 4 normally open contacts and a switching capacity of 4 000 W for incandescent lamp loads."},{"question":"Where can I buy 5TT5840-8 and what is the price?","answer":"This part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"What compliance documentation does Siemens provide for 5TT5840-8?","answer":"The evidence does not list specific compliance certifications (RoHS, REACH, UL, IEC) for this order code. Standard Siemens SENTRON products typically carry CE marking and are designed to IEC/EN 60947 series standards, but confirm documentation requirements at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/5TT5840-8","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/5TT5840-8 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}}