{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU1146-4LD1","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU1146-4LD1","canonicalUrl":"https://aoctrl.com/siemens/3RU1146-4LD1","factsUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4LD1","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU1146-4LD1 thermal overload relay, size S3, Class 10 trip, screw-type main terminals, IP20 front, ATEX certified.","salesMarkdown":"The relay dissipates 7 W per pole under load, so the enclosure's internal temperature rise needs to account for that heat — especially when grouping multiple relays in a compact panel. Auxiliary contact ratings are given for multiple control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the switching capacities for the built-in N/C and N/O contacts that signal the contactor coil or PLC input. The 400 V / 1 A rating confirms it can switch a 400 VAC control circuit directly. Surge voltage resistance is rated at 8 kV, which aligns with IEC 60947-1 overvoltage category III for industrial environments — meaning it withstands switching transients on a 400 V supply without flashover. The relay itself is not intended for washdown areas; it lives inside a panel. Mounting is stand-alone, not DIN-rail snap-on. Clearance distances are specified: 0 mm upwards, forwards, backwards, and downwards, but 6 mm to the side — so side-by-side mounting is possible with a 6 mm gap. Dimensions are 120 mm high, 70 mm wide, and 140 mm deep. That depth includes the screw-type main terminals and the cage-clamp auxiliary terminals. The main circuit accepts solid or stranded conductors: 2× (0.5…2.5 mm²) for the auxiliary circuit, and 2× (10…50 mm²) or single 10…70 mm² for the main circuit. AWG equivalents for the auxiliary contacts are 2× (20…14). ## Coordination and fusing For Type 1 coordination (no damage to the relay under fault, but may need replacement), a gG fuse of 250 A is required upstream. For Type 2 coordination (relay remains functional after a fault), the fuse drops to 160 A gG. These values guide the upstream protection selection in the motor branch circuit. ## Environmental limits Relative humidity tolerance is 100%, so condensation inside a non-condensing enclosure is acceptable. Shock resistance is 8g for 10 ms, typical for industrial panel-mounted gear.","metaTitle":"Siemens 3RU1146-4LD1 SIRIUS Thermal Overload Relay, Class 10","metaDescription":"Siemens 3RU1146-4LD1 SIRIUS thermal overload relay, size S3, Class 10 trip. IP20 front, ATEX certified, screw-type main terminals. Current 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 ... 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":"stand-alone installation","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":"Cage Clamp terminals","Relative Humidity During Operation":"100 %","With Type Of Assignment 2 Required":"gG: 160 A","Surge Voltage Resistance Rated Value":"8 kV","With Type Of Coordination 1 Required":"gG: 250 A","for 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":"70 ... 90 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=143795&mlfb=3RU1146-4LD1","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4LD1/alternatives.json"},"ai":{"faq":[{"question":"What compliance documentation does this relay carry?","answer":"It is RoHS compliant with a substance prohibitance date of 07/01/2006, and it holds ATEX certification DMT 98 ATEX G 001 for use in explosive atmospheres. The reference code per IEC 81346-2 is F (protective device)."},{"question":"What are the key ratings for the auxiliary contacts?","answer":"The auxiliary contacts are rated 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the switching capacities for the built-in N/C and N/O signaling contacts."},{"question":"What is the trip class and what does it mean?","answer":"It is Class 10, meaning the relay will trip within 10 seconds at 7.2× the current setting. This matches the thermal protection curve for standard AC induction motors during a locked-rotor condition."},{"question":"What are the mounting clearances?","answer":"Clearances are 0 mm upwards, forwards, backwards, and downwards, with 6 mm required to the side. The relay can be mounted on a vertical surface and rotated ±135° or tilted ±45°."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU1146-4LD1","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/3RU1146-4LD1 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}}