{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU1146-4FB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU1146-4FB0","canonicalUrl":"https://aoctrl.com/siemens/3RU1146-4FB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4FB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU1146-4FB0 thermal overload relay, S3 size, CLASS 10, screw-type terminals for main and control circuits, IP20 front, ATEX certified.","salesMarkdown":"This relay mounts directly onto a contactor (contactor mounting), so the kit is complete: no separate bracket or wiring between the relay and contactor main poles. The S3 frame size handles main circuit conductors up to 70 mm² stranded or 50 mm² fine-stranded, with screw-type terminals on both the main and auxiliary circuits. That means this relay can terminate motor leads up to about 1/0 AWG without needing adapter lugs — a solid fit for a 30–50 hp motor at 400 V. The auxiliary contacts are rated for 1 A at 24 V, 3 A at 120 V, and 2 A at 230 V, which covers most PLC input or contactor coil feedback circuits. Power dissipation is 4.5 W per pole, so in a multi-relay enclosure you need to account for 13.5 W total heat from the main poles — factor that into your panel cooling budget. This relay mounts directly onto a SIRIUS S3 contactor — no DIN rail required for the relay itself, though the contactor typically snaps onto a DIN rail. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards, with 6 mm to the side. That means you can pack relays side-by-side with no vertical gap, but leave 6 mm between adjacent units for heat dissipation. The front face is IP20, so finger-safe once the panel door is closed, but not washdown-rated — keep it inside the enclosure. It handles 100 % relative humidity (condensing), so it's fine in non-climate-controlled enclosures in humid plants. Shock resistance is 8g for 10 ms — adequate for most industrial machinery but not for high-shock applications like forging presses. Surge voltage resistance is 8 kV, which meets IEC 60947-1 overvoltage category III for 400 V systems.","metaTitle":"Siemens 3RU1146-4FB0 SIRIUS thermal overload relay, S3, CLAS","metaDescription":"Siemens SIRIUS 3RU1146-4FB0 thermal overload relay, S3 size, CLASS 10 trip, IP20 front, ATEX, screw terminals. Active production. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Depth":"140 mm","Solid":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Width":"70 mm","title":"3RU1146-4FB0","Height":"120 mm","Upwards":"0 mm","at 24 V":"1 A","Forwards":"0 mm","Per Pole":"4.5 W","Stranded":"2x (10 ... 50 mm²), 10 ... 70 mm²","at 110 V":"0.22 A","at 120 V":"3 A","at 125 V":"0.22 A","at 220 V":"0.11 A","at 230 V":"2 A","at 400 V":"1 A","Backwards":"0 mm","Downwards":"0 mm","Trip Class":"CLASS 10","At The Side":"6 mm","description":"Overload relay 28...40 A For motor protection Size S3, Class 10 Contactor mounting Main circuit: Screw terminal Auxiliary circuit: Screw terminal Manual-Automatic-Reset!!! Phased-out product!!! Successor is SIRIUS 3RU2 Preferred successor type is >>3RU2136-4FB0<<","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +70 °C","During Transport":"-55 ... +80 °C","Fastening Method":"Contactor mounting","Shock Resistance":"8g / 10 ms","Mounting Position":"with vertical mounting surface +/-135° rotatable, with vertical mounting surface +/- 45° tiltable to the front and back","Product Brand Name":"SIRIUS","Type Of Protection":"DMT 98 ATEX G 001","Product Designation":"thermal overload relay","Size Of Overload Relay":"S3","For Main Current Circuit":"screw-type terminals","Substance Prohibitance (Date)":"07/01/2006","protection class IP on the front":"IP20","For Auxiliary And Control Circuit":"screw-type terminals","Relative Humidity During Operation":"100 %","With Type Of Assignment 2 Required":"gG: 80 A","Surge Voltage Resistance Rated Value":"8 kV","With Type Of Coordination 1 Required":"gG: 160 A","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","reference code according to IEC 81346-2":"F","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Number Of Poles For Main Current Circuit":"3","Touch Protection Against Electrical Shock":"finger-safe","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","Size Of Contactor Can Be Combined Company-Specific":"S3","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 6 A, quick: 10 A","insulation voltage with degree of pollution 3 at AC rated value":"1 000 V","Product Component Removable Terminal For Auxiliary And Control Circuit":"No","power loss [W] for rated value of the current at AC in hot operating state":"13.5 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"28 ... 40 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/a3657ff710034d6cb571e5440d8b60d8.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=268166&mlfb=3RU1146-4FB0"},"ai":{"faq":[{"question":"What are the key dimensions and mounting clearances?","answer":"The relay measures 70 mm wide, 120 mm high, and 140 mm deep. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards, with 6 mm to the side. It mounts directly onto a SIRIUS S3 contactor."},{"question":"What conductor sizes does the 3RU1146-4FB0 accept?","answer":"The main circuit terminals accept stranded conductors from 10 to 70 mm² and fine-stranded from 10 to 50 mm². The auxiliary and control circuit terminals accept solid conductors 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²), or AWG 2x (20 to 16) and 2x (18 to 14). All terminals are screw-type."},{"question":"What compliance certifications does this relay carry?","answer":"It carries ATEX approval (DMT 98 ATEX G 001) for use in potentially explosive gas atmospheres. The front protection class is IP20. The substance prohibition date of 07/01/2006 indicates RoHS compliance. Surge voltage resistance is 8 kV per IEC 60947-1."},{"question":"What fuse coordination is required for this relay?","answer":"For type 2 coordination (no damage to the relay on short circuit), use gG 80 A fuses. For type 1 coordination (relay may need replacement), gG 160 A fuses are permitted."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU1146-4FB0","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/3RU1146-4FB0 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}}