{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2131-2KV40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2131-2KV40","canonicalUrl":"https://aoctrl.com/siemens/3RH2131-2KV40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2131-2KV40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RH2 coupling contactor relay, 3 NO + 1 NC, 36 V DC coil with integrated suppressor diode, spring-loaded terminal, frame size S00.","salesMarkdown":"The Siemens 3RH2131-2KV40 is a coupling contactor relay in the SIRIUS 3RH2 family, designed to bridge PLC outputs to higher-current contactor coils or other loads in a control panel. It carries 3 normally-open and 1 normally-closed contact set, with a 36 V DC coil rated for 0.7 to 1.25 times the rated control supply voltage. The integrated suppressor diode clips the inductive kickback when the coil de-energizes, which means you don't need an external flyback diode across the coil terminals — a common point of failure on panels where that diode gets omitted or reversed. Frame size S00 keeps the footprint compact for DIN-rail mounting inside a standard control cabinet. RoHS compliance dates from October 2009, so it meets the EU restriction on hazardous substances for current builds. The 36 V DC coil with a 0.7–1.25× Us operating range means the relay pulls in reliably between about 25 V and 45 V DC. That tolerance covers a sagging 24 V bus (common on long cable runs to remote I/O) and still holds in during a moderate overvoltage. The 3 NO + 1 NC contact arrangement is the standard coupling relay complement: three poles to switch a three-phase contactor coil, one NC for feedback or status interlock. The integrated suppressor diode absorbs the inductive flyback spike internally, protecting the PLC output. Frame size S00 and the not-expandable-with-auxiliary-switch note mean this relay is a fixed-contact-count device. If you need additional auxiliary contacts beyond the 3 NO + 1 NC, you must select a different 3RH2 variant or add an external auxiliary contact block. For a simple PLC-to-contactor coupling where four contacts are enough, this is the cleanest option — no extra parts to spec.","metaTitle":"Siemens 3RH2131-2KV40 Coupling Contactor Relay, 36 V DC, Spr","metaDescription":"Siemens 3RH2131-2KV40 coupling contactor relay, 3 NO + 1 NC, 36 V DC coil with integrated suppressor diode, spring-loaded terminal, frame size S00. Active production. RoHS complian","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Contactors"],"specifications":{"title":"3RH2131-2KV40","Group Code":"R711","description":"coupling contactor relay, 3 NO + 1 NC, 36 V DC, 0.7-1.25*Us, with integrated suppressor diode, spring-loaded terminal, frame size S00, suitable for PLC outputs, not expandable with auxiliary switch","Product Group":"5331","Product class":"A: Standard product which is a stock item could be returned within the returns guidelines/period.","Quantity Unit":"1 Piece","Product Family":"Ordering Data Overview","lifecycle_stage":"current","Packaging Quantity":"1","Export Control Regulations":"AL : N / ECCN : N","Packaging dimensions (L x W x H)":"80.00 x 75.00 x 50.00 mm","Compliance with the substance restrictions according to RoHS directive":"Since: 01-10-09","REACH Art. 33 Duty to inform according to the current list of candidates":"Lead CAS-No. 7439-92-1 > 0,1 % (w / w)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/3613a0d35ed9640b81bdc5c6aa32c922.pdf","sourceUrl":"https://sieportal.siemens.com/en-ae/products-services/detail/3RH2131-2KV40?tree=CatalogTree"},"ai":{"faq":[{"question":"Does the integrated suppressor diode eliminate the need for an external flyback diode?","answer":"Yes. The coil includes a built-in suppressor diode that clips the inductive kickback when the relay de-energizes. You do not need to add an external diode across the coil terminals, which simplifies wiring and eliminates a common assembly error."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2131-2KV40","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/3RH2131-2KV40 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}}