{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2911-4NF11","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2911-4NF11","canonicalUrl":"https://aoctrl.com/siemens/3RH2911-4NF11","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2911-4NF11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch, 3RH2911-4NF11, 1 NO + 1 NC solid-state compatible, snap-on front mount for contactors S00/S0/S2/S3, ring terminal connection, 43.7 mm depth, 36 mm width, 37.5 mm height.","salesMarkdown":"The Siemens SIRIUS 3RH2911-4NF11 is a front-mounted auxiliary switch block designed specifically for the 3RT2 power contactor and 3RH2 contactor relay series. It snaps onto the front of contactors in sizes S00, S0, S2, and S3, adding one normally-open and one normally-closed instantaneous auxiliary contact to the assembly. The contacts are rated as solid-state compatible, meaning they are designed for reliable low-level switching — the spec calls out one incorrect switching operation per 100 million operations at 5 V and 1 mA. This makes the block suitable for directly driving PLC inputs or solid-state logic without intermediate relays. These values confirm it is rated for the same voltage class as the SIRIUS contactor line it mounts to — no derating needed when used on 400 V or 690 V distribution. The contacts are rated for 0.3 A at 24 V, 48 V, and 60 V. This is the continuous current rating for the auxiliary circuit — adequate for signaling and control loads, not for power switching. The block is a mirror contact per IEC 60947-4-1 when used with specific 3RT2 contactor variants. This means the NC contact mechanically mirrors the main contact position — critical for safety circuits where you need positive confirmation that the main contacts are open before allowing access. ## Physical Integration and Wiring The block measures 36 mm wide, 37.5 mm high, and 43.7 mm deep — it adds roughly 44 mm to the front projection of the contactor. It snaps onto the contactor front without tools and does not increase the DIN-rail footprint. Termination is via ring cable lug connection — the wire is crimped to a ring terminal and bolted to the contact screw. This is a vibration-resistant connection typical for panel builds where maintenance access is infrequent. The front protection class is IP00, so the block is intended for installation inside an enclosure — not for exposed or washdown environments. No adapter or wiring change is needed — it drops into the existing front slot.","metaTitle":"Siemens 3RH2911-4NF11 SIRIUS Auxiliary Switch, 1 NO + 1 NC,","metaDescription":"Siemens SIRIUS 3RH2911-4NF11 auxiliary switch, 1 NO + 1 NC solid-state compatible contacts, snap-on front mount for 3RT2/3RH2 contactors. Ring terminal connection, 690 V insulation","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"43.7 mm","Width":"36 mm","title":"3RH2911-4NF11","Height":"37.5 mm","at 24 V":"0.3 A","at 48 V":"0.3 A","at 60 V":"0.3 A","description":"auxiliary switch, solid-state compatible, on the front, 1 NO + 1 NC,.3/.4, --/--, --/--,.1/.2, current path: 1 NO (solid-state compatible), --, --, 1 NC (solid-state compatible), ring cable lug connection, for contactors 3RT2 and contactor relays 3RH2","During Storage":"-55 ... +80 °C","Leading Contact":"0","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","Fastening Method":"snap-on mounting","Product Category":"Auxiliary switch","Lagging Switching":"0","Size Of Contactor":"S00, S0, S2, S3","Product Brand Name":"SIRIUS","Product Designation":"auxiliary switch","Suitability For Use":"Contactor relay and power contactor","Design Of The Product":"for snapping onto the front","Instantaneous Contact":"1","Substance Prohibitance (Date)":"10/01/2009","protection class IP on the front":"IP00","Surge Voltage Resistance Rated Value":"6 kV","Contact Reliability Of Auxiliary Contacts":"one incorrect switching operation of 100 million switching operations (5 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes; with 3RT2.2/3/4","Mechanical Service Life (Operating Cycles) Typical":"5 000 000","Type Of Electrical Connection For Auxiliary And Control Circuit":"ring terminal lug connection","insulation voltage with degree of pollution 3 at AC rated value":"690 V","number of CO contacts of auxiliary contacts instantaneous contact":"0"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/372e8b50659f98a9ea72116ea13ed2a3.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=180437&mlfb=3RH2911-4NF11"},"ai":{"faq":[{"question":"What contactors does this auxiliary switch fit?","answer":"It fits Siemens SIRIUS 3RT2 power contactors and 3RH2 contactor relays in frame sizes S00, S0, S2, and S3. It snaps onto the front of the contactor."},{"question":"What does 'solid-state compatible' mean for this switch?","answer":"The contacts are rated for reliable switching at low voltage and current levels — one faulty operation per 100 million at 5 V, 1 mA. This means they can directly drive PLC inputs or solid-state logic without intermediate relays."},{"question":"What is the insulation voltage and surge rating?","answer":"The insulation voltage is 690 V at pollution degree 3, and the rated surge voltage resistance is 6 kV. This matches the voltage class of the SIRIUS contactor line."},{"question":"What termination type does the 3RH2911-4NF11 use?","answer":"It uses ring cable lug connection — wires are crimped to ring terminals and bolted to the contact screws. This provides a vibration-resistant connection."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2911-4NF11","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/3RH2911-4NF11 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}}