{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH2911-4FA40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH2911-4FA40","canonicalUrl":"https://aoctrl.com/siemens/3RH2911-4FA40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH2911-4FA40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch, 3RH2911-4FA40, 4 N/O + 0 N/C, snap-on front mount for contactor sizes S00, S0, S2, S3, ring terminal lug connection.","salesMarkdown":"The Siemens 3RH2911-4FA40 is a SIRIUS auxiliary switch block that snaps onto the front of contactor relays and power contactors in sizes S00, S0, S2, and S3. It provides 4 normally-open instantaneous contacts and no normally-closed or lagging contacts, making it a straightforward add-on for signaling or interlock circuits on a contactor. The connection type is ring terminal lug, which is a secure, vibration-resistant termination common in panel builds where screw terminals are standard. Rated operational current at AC-15 at 24 V is 10 A, and at 230 V it carries 6 A — these are the contact ratings for inductive loads like contactor coils. The AC-12 maximum rating is also 10 A, covering resistive loads. For DC switching, the ratings drop with voltage: 6 A at 24 V, 2 A at 48/60 V, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220/250 V. This derating curve is typical for DC arcs — expect to size for the actual DC voltage in your circuit. The mirror contact feature per IEC 60947-4-1 is present when used with 3RT2 contactors, meaning the N/O contacts cannot weld closed if a power contactor welds — a critical safety function for fail-safe circuits. Because it snaps onto the front of S00 through S3 contactors, it is a direct spare for any panel using those frame sizes. No rewiring is needed if replacing a failed unit of the same type. Dimensions: 36 mm wide, 37.5 mm tall, 43.7 mm deep. The snap-on mounting means it clips directly onto the contactor front without DIN rail space. IP00 on the front — no water or dust ingress protection, so this switch lives inside a closed panel or enclosure, not on the machine exterior. RoHS compliance date is 2009-10-01, covering EU substance restrictions.","metaTitle":"Siemens 3RH2911-4FA40 SIRIUS Auxiliary Switch, snap-on front","metaDescription":"Siemens SIRIUS 3RH2911-4FA40 auxiliary switch for S00-S3 contactors. 4 N/O + 0 N/C, snap-on front mount, ring terminal connection. AC-15 rated 10 A at 24 V. Current lifecycle stage","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"43.7 mm","Width":"36 mm","Height":"37.5 mm","at 24 V":"6 A","at 48 V":"2 A","at 60 V":"2 A","at 110 V":"1 A","at 125 V":"0.9 A","at 220 V":"0.3 A","at 230 V":"6 A","at 250 V":"0.3 A","at 400 V":"3 A","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","at 24 V rated value":"10 A","at 60 V rated value":"4.7 A","at 110 V rated value":"3 A","at 220 V rated value":"1.2 A","at 440 V rated value":"0.5 A","at 600 V rated value":"0.26 A","Design Of The Product":"for snapping onto the front","Instantaneous Contact":"4","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":"1 faulty switching per 100 million (17 V, 1 mA)","mirror contact according to IEC 60947-4-1":"Yes; with 3RT2","operational current at AC-15 at 690 V rated value":"1 A","Mechanical Service Life (Operating Cycles) Typical":"10 000 000","operational current of auxiliary contacts at AC-12 maximum":"10 A","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,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/38c49ef333ba36f00c306c3eaace073f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=455354&mlfb=3RH2911-4FA40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH2911-4FA40/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for this auxiliary switch?","answer":"AC-15 rated 10 A at 24 V and 6 A at 230 V. DC ratings range from 6 A at 24 V down to 0.3 A at 250 V. Surge voltage resistance is 6 kV, and mechanical life is 10 million cycles."},{"question":"Which contactors does this auxiliary switch fit?","answer":"It snaps onto the front of SIRIUS contactor sizes S00, S0, S2, and S3, including both contactor relays and power contactors."},{"question":"Does it have mirror contact functionality?","answer":"Yes, the mirror contact per IEC 60947-4-1 is confirmed when used with 3RT2 contactors, providing a safety-related N/O contact that cannot weld closed."},{"question":"What type of connection does it use?","answer":"Ring terminal lug connection for the auxiliary and control circuits."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH2911-4FA40","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/3RH2911-4FA40 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}}