{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU1146-4MD0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU1146-4MD0","canonicalUrl":"https://aoctrl.com/siemens/3RU1146-4MD0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4MD0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU1146-4MD0 thermal overload relay, Class 10, size S3, screw-type main terminals, Cage Clamp auxiliary terminals, IP20 front, ATEX certified.","salesMarkdown":"The Siemens 3RU1146-4MD0 is a SIRIUS thermal overload relay — size S3 — used to protect three-phase motors against overload and phase failure by monitoring motor current and tripping the contactor when the thermal model exceeds the Class 10 curve. It mounts directly to a contactor (contactor mounting), so the whole assembly slides onto a DIN rail or screws to a backplate as a single unit — no separate bracket or wiring between the relay and contactor coil. The relay accepts screw-type terminals for the main circuit — solid wire 2x (0.5 … 2.5 mm²) or stranded 2x (10 … 50 mm²) and up to 10 … 70 mm² — so it handles motor leads from fractional-horsepower up to about 30 kW at 400 V without needing adapters. Auxiliary and control circuits use Cage Clamp terminals (2x 20 … 14 AWG), which is a spring-cage connection — no screw tightening needed, just push the stripped wire in. That saves time on a multi-relay panel. Shock resistance rated at 8g / 10 ms, so it holds calibration on a machine tool or a conveyor line with moderate vibration. Surge voltage resistance of 8 kV (impulse) means it can handle switching transients from contactor coils and nearby VFDs without false tripping. The relay is 70 mm wide, 120 mm tall, 140 mm deep — the S3 footprint. It mounts with a vertical mounting surface and can be rotated ±135° or tilted ±45° front-to-back, so you can fit it into tight corners without special brackets. Clearances: 0 mm upwards, forwards, backwards, and downwards — so it can butt against other components or the cabinet wall with no air gap needed for cooling (the relay is self-heating, but the contactor handles the main heat). Side clearance is 6 mm. Power dissipation per pole is 7 W — total 21 W at full load. That's modest, but if you pack several relays in a small enclosure, you'll want to account for it in the thermal design. This lets you size the upstream protection to match your selectivity scheme. The relay carries ATEX approval (DMT 98 ATEX G 001), so it's suitable for use in potentially explosive atmospheres — gas groups — when paired with an appropriate contactor and enclosure. Relative humidity during operation: 100 % — no derating needed for condensing environments, as long as the enclosure is rated for it.","metaTitle":"Siemens 3RU1146-4MD0 SIRIUS Thermal Overload Relay, Class 10","metaDescription":"Siemens 3RU1146-4MD0 SIRIUS thermal overload relay, Class 10 trip, S3 size, 70x120x140 mm, IP20 front, ATEX, screw main/Cage Clamp aux terminals. Active production, sourced to orde","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Depth":"140 mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"70 mm","Height":"120 mm","Upwards":"0 mm","at 24 V":"1 A","Forwards":"0 mm","Per Pole":"7 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","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","at AWG cables for main contacts":"2x (10 ... 1/0), 1x (10 ... 2/0)","protection class IP on the front":"IP20","For Auxiliary And Control Circuit":"Cage Clamp terminals","Relative Humidity During Operation":"100 %","With Type Of Assignment 2 Required":"gG: 200 A","Surge Voltage Resistance Rated Value":"8 kV","With Type Of Coordination 1 Required":"gG: 250 A","at AWG cables for auxiliary contacts":"2x (20 ... 14)","reference code according to IEC 81346-2":"F","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Touch Protection Against Electrical Shock":"finger-safe","Finely Stranded Without Core End Processing":"2x (0.5 ... 1.5 mm²)","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":"21 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"80 ... 100 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=101023&mlfb=3RU1146-4MD0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4MD0/alternatives.json"},"ai":{"faq":[{"question":"What compliance documentation does the 3RU1146-4MD0 carry?","answer":"It carries ATEX approval (DMT 98 ATEX G 001) for gas groups, and the substance prohibitance date is 07/01/2006 (RoHS-style). The front is IP20 rated."},{"question":"What are the key dimensions and clearances for this relay?","answer":"Width 70 mm, height 120 mm, depth 140 mm. Clearances: 0 mm upwards, forwards, backwards, downwards; 6 mm at the side."},{"question":"What wire sizes does the 3RU1146-4MD0 accept?","answer":"Main circuit screw terminals: solid 2x (0.5 … 2.5 mm²) or stranded 2x (10 … 50 mm²) and 10 … 70 mm². Auxiliary Cage Clamp terminals: 2x (20 … 14 AWG)."},{"question":"What backup fuse is required for Type 2 coordination?","answer":"For Type 2 coordination (no damage to the relay), a gG 200 A fuse is required. For Type 1 coordination (relay may be damaged), gG 250 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU1146-4MD0","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/3RU1146-4MD0 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}}