{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU6126-4NB1","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU6126-4NB1","canonicalUrl":"https://aoctrl.com/siemens/3RU6126-4NB1","factsUrl":"https://aoctrl.com/api/mcp/products/3RU6126-4NB1","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU6126-4NB1 thermal overload relay, 23-28 A adjustable, Class 10, size S0, screw-type terminals, stand-alone installation.","salesMarkdown":"## Integrator note — SIRIUS 3RU6126-4NB1 The Siemens 3RU6126-4NB1 is a SIRIUS thermal overload relay sized for motor protection in the 23-28 A adjustable range, Class 10 trip curve. It mounts stand-alone on the panel or directly onto an S0-frame contactor. Screw terminals on both main and auxiliary circuits accept 2x (0.5-1.5 mm²) solid or stranded, or 2x (0.75-2.5 mm²) with ferrules. The adjustable current range of 23-28 A sets the motor full-load current (FLC) the relay protects. ## Deployment context Mounts in any position in the control panel. The stand-alone installation method means it can be DIN-rail mounted or screw-fixed directly to a backplate. The manual/automatic reset selector gives the commissioning engineer flexibility for remote restart or local intervention after a trip.","metaTitle":"Siemens 3RU6126-4NB1 SIRIUS Overload Relay, 23-28 A, Class 1","metaDescription":"Siemens SIRIUS 3RU6126-4NB1 thermal overload relay, 23-28 A adjustable, Class 10 trip, S0 size, 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":"95 mm","Width":"45 mm","title":"3RU6126-4NB1","Height":"97 mm","at 24 V":"2 A","Per Pole":"3.2 W","at 110 V":"0.22 A","at 230 V":"2 A","Trip Class":"CLASS 10","description":"Overload relay 23...28 A size S0, class 10, for motor protection stand-alone installation main circuit: screw terminal AUX. circuit: screw terminal manual automatic reset","lifecycle_stage":"current","During Operation":"-40 ... +70 °C","During Transport":"-55 ... +80 °C","Fastening Method":"stand-alone installation","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","For Main Current Circuit":"screw-type terminals","power loss [W] total typical":"7.1 W","Operating Voltage Rated Value":"690 V","Substance Prohibitance (Date)":"05/01/2012","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"28 A","for AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","For Auxiliary And Control Circuit":"screw-type terminals","Relative Humidity During Operation":"0 ... 90 %","Surge Voltage Resistance Rated Value":"6 kV","for AWG cables for auxiliary contacts":"2x (20 ... 16), 2x (18 ... 14)","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","shock resistance according to IEC 60068-2-27":"8g / 11 ms","Required Spacing For Grounded Parts At The Side":"6 mm","Size Of Contactor Can Be Combined Company-Specific":"S0","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Arrangement Of Electrical Connectors For Main Current Circuit":"Top and bottom","Tightening Torque For Main Contacts With Screw-Type Terminals":"2 ... 2.5 N·m","insulation voltage with degree of pollution 3 at AC rated value":"690 V","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":"23 ... 28 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/0b72f7cef92404f4b36b925b1709d282.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=621552&mlfb=3RU6126-4NB1"},"ai":{"faq":[{"question":"What contactor frame does this relay combine with?","answer":"It is designed to combine with S0-frame contactors from the SIRIUS family, such as the 3RT102 or 3RT602 series."},{"question":"What are the key ratings for fit verification?","answer":"Adjustable current range 23-28 A, Class 10 trip, rated operating voltage 690 V, 50/60 Hz, 3 poles. Screw terminals for main and auxiliary circuits."},{"question":"What compliance documentation is available?","answer":"The part carries a substance prohibitance date of 05/01/2012, indicating RoHS/REACH compliance. The SIRIUS series typically provides UL, CSA, and CE certifications; verify specific approvals with the order code."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU6126-4NB1","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/3RU6126-4NB1 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}}