{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-4EB1","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-4EB1","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-4EB1","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4EB1","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-4EB1 thermal overload relay, CLASS 10, size S0, 690 V rated, 15 kW at 400 V, screw terminals.","salesMarkdown":"It protects motors against overload and phase failure by monitoring the current draw and tripping the associated contactor when the thermal model reaches the trip threshold. Rated insulation voltage is 690 V, with power ratings of 15 kW at 400 V, 18.5 kW at 500 V, and 30 kW at 690 V. The AC-3e maximum voltage is also 690 V, so it's suited for 400 V and 690 V motor circuits common in European and export panels. The auxiliary switch is integrated, saving a separate aux block on the contactor. The thermal overload release is ambient-compensated from -40 to +60 °C, so the trip curve stays stable across the panel's internal temperature range. Terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, with M4 main contact screws. The screwdriver spec is Pozidriv PZ2 with a 5 to 6 mm shaft diameter — standard for panel builders. ## Deployment context The S0 frame size is a common footprint across the SIRIUS family, so panel cutouts and wiring layouts for the contactor side are standard. The integrated auxiliary switch eliminates one wiring step during panel assembly.","metaTitle":"Siemens 3RU2126-4EB1 SIRIUS Thermal Overload Relay, CLASS 10","metaDescription":"Siemens 3RU2126-4EB1 SIRIUS thermal overload relay, CLASS 10, S0 size, 690 V rated, 15 kW at 400 V. Current production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Overload Relays"],"specifications":{"Note":"for message \"Tripped\"","Depth":"95 mm","Width":"45 mm","Height":"97 mm","at 24 V":"2 A","at 60 V":"0.3 A","Per Pole":"3.2 W","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","Trip Class":"CLASS 10","Rated Value":"690 V","During Storage":"-55 ... +80 °C","lifecycle_stage":"current","During Operation":"-40 ... +70 °C","During Transport":"-55 ... +80 °C","Fastening Method":"stand-alone installation","For Main Contacts":"M4","Mounting Position":"any","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"thermal overload relay","at 400 V rated value":"15 kW","at 480 V rated value":"32 A","at 500 V rated value":"18.5 kW","at 600 V rated value":"32 A","at 690 V rated value":"30 kW","Size Of Overload Relay":"S0","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-40 ... +60 °C","MTTF with high demand rate":"2 280 y","Design Of Screwdriver Shaft":"Diameter 5 ... 6 mm","Size Of The Screwdriver Tip":"Pozidriv PZ 2","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","Design Of The Auxiliary Switch":"integrated","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"32 A","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","For Auxiliary And Control Circuit":"screw-type terminals","Between Main And Auxiliary Circuit":"440 V","Relative Humidity During Operation":"10 ... 95 %","Display Version For Switching Status":"Slide switch","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","Of The Auxiliary And Control Contacts":"M3","Between Auxiliary And Auxiliary Circuit":"440 V","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","For Main Contacts With Screw-Type Terminals":"2 ... 2.5 N·m","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","shock resistance according to IEC 60068-2-27":"8g / 11 ms","For Auxiliary Contacts With Screw-Type Terminals":"0.8 ... 1.2 N·m","operational current at AC-3e at 400 V rated value":"32 A","Size Of Contactor Can Be Combined Company-Specific":"S0","contact rating of auxiliary contacts according to UL":"B600 / R300","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Arrangement Of Electrical Connectors For Main Current Circuit":"Top and bottom","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gG: 6 A, quick: 10 A","insulation voltage with degree of pollution 3 at AC rated value":"690 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":"9.6 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"27 ... 32 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b96b9f04fab73d4445a195462a3eb810.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=473243&mlfb=3RU2126-4EB1","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4EB1/alternatives.json"},"ai":{"faq":[{"question":"What does the note 'for message Tripped' mean on this relay?","answer":"The note indicates that the auxiliary contact position labeled 'Tripped' is used to signal a trip condition to a PLC or indicator lamp. It is a standard auxiliary contact on the integrated switch."},{"question":"What is the depth of the 3RU2126-4EB1?","answer":"The depth is 95 mm, with a width of 45 mm and height of 97 mm."},{"question":"Where can I buy the 3RU2126-4EB1 and how is it quoted?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — no stock count or price is listed here."},{"question":"Will the 3RU2126-4EB1 drop into a panel designed for a 3RV1011-1HA10?","answer":"No — the 3RV1011-1HA10 is a circuit breaker, not a thermal overload relay. The 3RU2126-4EB1 is a separate overload relay that mounts to a contactor, so the panel layout and wiring differ. They are not drop-in interchangeable."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-4EB1","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/3RU2126-4EB1 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}}