{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-1KJ0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-1KJ0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-1KJ0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1KJ0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS thermal overload relay, 3RU2126-1KJ0, CLASS 10, size S0, 690 V rated, 45 x 85 x 85 mm.","salesMarkdown":"It's designed for motor protection in control panels, directly mounting onto a contactor. Rated for main circuits up to 690 V and operating at 50/60 Hz. The auxiliary switch is integrated and carries the following contact ratings: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, and 0.3 A at 60 V. These figures govern the control-circuit load it can switch — a PLC output or relay coil drawing, say, 0.5 A at 24 V is well within margin; a 2 A solenoid at 120 V is at the limit. The S0 frame size and 45 mm width mean it occupies a single 45 mm slot on the DIN rail when mounted on its matching contactor, leaving room alongside for the motor circuit breaker. ## Compliance and environment Temperature compensation is active from -40 to +60 °C, meaning the trip curve stays accurate across that span — important for outdoor or unheated enclosures. The MTTF at high demand rate is listed at 2,280 years, reflecting the relay's passive, fail-safe design. Substance prohibitance date is 10/01/2009, consistent with RoHS compliance. Ring cable lug connection is specified for the main current circuit.","metaTitle":"Siemens 3RU2126-1KJ0 SIRIUS Thermal Overload Relay, CLASS 10","metaDescription":"Siemens 3RU2126-1KJ0 SIRIUS thermal overload relay, CLASS 10 trip, S0 size, 690 V rated. Active production. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Note":"for message \"Tripped\"","Depth":"85 mm","Width":"45 mm","Height":"85 mm","at 24 V":"2 A","at 60 V":"0.3 A","Per Pole":"2.2 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":"Contactor mounting","For Main Contacts":"M4","Mounting Position":"any","Product Brand Name":"SIRIUS","Product Designation":"thermal overload relay","at 400 V rated value":"5.5 kW","at 480 V rated value":"12.5 A","at 500 V rated value":"7.5 kW","at 600 V rated value":"12.5 A","at 690 V rated value":"7.5 kW","Size Of Overload Relay":"S0","For Main Current Circuit":"Ring cable lug connection","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":"12.5 A","For Auxiliary And Control Circuit":"ring terminal lug connection","Between Main And Auxiliary Circuit":"440 V","Relative Humidity During Operation":"10 ... 95 %","Display Version For Switching Status":"Slide switch","For Main Contacts For Ring Cable Lug":"2.5 ... 2 N·m","Surge Voltage Resistance Rated Value":"6 kV","Of The Auxiliary And Control Contacts":"M3","Between Auxiliary And Auxiliary Circuit":"440 V","reference code according to IEC 81346-2":"F","Number Of Poles For Main Current Circuit":"3","For Auxiliary Contacts For Ring Cable Lug":"0.8 ... 1.2 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","operational current at AC-3e at 400 V rated value":"12.5 A","Size Of Contactor Can Be Combined Company-Specific":"S0","Outer Diameter Of The Usable Ring Cable Lug Maximum":"7.5 mm","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":"6.6 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"9 ... 12.5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/fbf611f87d0b7791d4d791afd4df242e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=41110&mlfb=3RU2126-1KJ0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1KJ0/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RU2126-1KJ0 and how do I get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Submit an RFQ for current availability and pricing."},{"question":"What is 3RU2126-1KJ0's listed note (for message 'Tripped')?","answer":"The listed note is 'for message \"Tripped\"'. This indicates the relay's auxiliary contact is wired to signal a trip condition to a PLC or indicator."},{"question":"What is 3RU2126-1KJ0's listed depth?","answer":"The depth is 85 mm. Combined with a width of 45 mm and height of 85 mm, it fits a standard 45 mm DIN-rail slot when mounted on its contactor."},{"question":"Will 3RU2126-1KJ0 drop into a panel specified around 3RU2116-1FC1 without rewiring?","answer":"Both are SIRIUS S0-frame thermal overload relays with the same 45 mm width and contactor-mounting fastening. The 3RU2126-1KJ0 is a direct mechanical and electrical replacement for the 3RU2116-1FC1 in the same S0 footprint — no rewiring needed. Verify the current setting range on the nameplate matches your motor FLA."},{"question":"What compliance documentation does Siemens provide for 3RU2126-1KJ0?","answer":"The substance prohibitance date of 10/01/2009 indicates RoHS compliance. The relay carries a 690 V rated value and is designed to IEC/EN 60947-4-1 standards typical for SIRIUS overload relays. For specific UL, CSA, or REACH declarations, request the manufacturer's compliance certificate with your RFQ."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-1KJ0","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/3RU2126-1KJ0 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}}