{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU1146-4LB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU1146-4LB0","canonicalUrl":"https://aoctrl.com/siemens/3RU1146-4LB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU1146-4LB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU1146-4LB0 thermal overload relay, size S3, CLASS 10, screw terminals, 140 mm depth, IP20 front, ATEX approved.","salesMarkdown":"The Siemens 3RU1146-4LB0 is a SIRIUS thermal overload relay, size S3, designed for motor protection in a control panel. The IP20 front protection means it is safe for finger contact inside an enclosure but not for washdown environments. The 140 mm depth and 70 mm width are the critical panel-space numbers — this relay occupies a standard S3 footprint, so verify your DIN-rail clearance against the 120 mm height and the 140 mm projection. The screw-type terminals on both the main and auxiliary circuits accept stranded conductors up to 70 mm² on the main circuit and 2.5 mm² on the auxiliary side, which covers most motor branch circuits up to 160 A gG fuse coordination. The auxiliary contact ratings span 24 V to 400 V AC/DC (, –), so the N/C trip alarm can drive a PLC input or a panel lamp at the same voltage as the control circuit. ## Deployment context and approvals This relay carries ATEX approval (DMT 98 ATEX G 001,), so it is suitable for use in potentially explosive atmospheres when paired with an appropriate contactor and enclosure. The surge voltage resistance of 8 kV gives it solid margin for industrial mains transients. The mounting position is flexible — vertical surface with ±135° rotation and ±45° tilt — which helps when panel layout is tight. Per-pole power dissipation of 7 W means the relay contributes about 21 W total heat in a three-phase circuit; factor that into your enclosure thermal calculation. Shock resistance is 8g for 10 ms. ## Coordination and selectivity notes For type 1 coordination (starter may be damaged but no hazard to personnel), the limit is 250 A gG. These figures matter when you are sizing the branch circuit protection upstream of this relay and its contactor.","metaTitle":"Siemens 3RU1146-4LB0 SIRIUS Thermal Overload Relay, S3, Clas","metaDescription":"Siemens 3RU1146-4LB0 SIRIUS thermal overload relay, size S3, CLASS 10 trip, 140 mm depth, IP20 front, ATEX approved. Current production. Quoted to order against RFQ.","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":"3RU1146-4LB0","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","description":"Overload relay 70...90 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 >>3RU2146-4LB0<<","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: 160 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 ... 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":"21 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"70 ... 90 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$83.12","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/5eab8c3e43fe4945c901897223e2adbc.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=22188&mlfb=3RU1146-4LB0"},"ai":{"faq":[{"question":"What is the closest functional alternative to 3RU1146-4LB0?","answer":"The 3RT5046-1AM00 is a contactor in the same SIRIUS S3 frame size and can be paired with this overload relay, but it is not a direct functional substitute — the 3RU1146-4LB0 is the overload relay, not the contactor. For a true second-source overload relay in the same S3 size and CLASS 10 trip class, the Siemens 3RU1146-4LB0 is the current production part; no alternate manufacturer is on the approved list without a customer deviation."},{"question":"What is the depth of 3RU1146-4LB0?","answer":"The depth is 140 mm. This is the dimension from the mounting surface to the furthest projection, critical for enclosure depth clearance."},{"question":"What wire sizes does 3RU1146-4LB0 accept on the auxiliary terminals?","answer":"The auxiliary screw terminals accept solid conductors: 2x (0.5 to 1.5 mm²) and 2x (0.75 to 2.5 mm²). For AWG, the auxiliary contacts accept 2x (20 to 16) and 2x (18 to 14)."},{"question":"Will 3RU1146-4LB0 drop into a panel specified around 3RT5046-1AM00?","answer":"Yes, because the 3RU1146-4LB0 is designed for contactor mounting and shares the same SIRIUS S3 frame size as the 3RT5046-1AM00 contactor. It mounts directly onto that contactor without rewiring the main power circuit, provided the existing panel has the S3 footprint clearance."},{"question":"What compliance documentation does Siemens provide for 3RU1146-4LB0?","answer":"The relay carries ATEX approval DMT 98 ATEX G 001 and has a substance prohibition date of 07/01/2006, which aligns with RoHS compliance. Standard Siemens documentation includes the declaration of conformity for the ATEX directive and the CE marking. For specific UL or IEC certificates, request them with the RFQ."},{"question":"Where can I buy 3RU1146-4LB0 and what is the lead time?","answer":"This part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm lead time and price."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU1146-4LB0","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/3RU1146-4LB0 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}}