{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-1EJ0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-1EJ0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-1EJ0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1EJ0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-1EJ0 thermal overload relay, size S0, Class 10 trip, 85 mm depth, contactor-mount, 1.5 kW at 400 V.","salesMarkdown":"## SIRIUS 3RU2126-1EJ0 — thermal overload relay, size S0, Class 10 The Siemens 3RU2126-1EJ0 is a SIRIUS thermal overload relay in the size S0 frame, designed for direct mounting onto a contactor (fastening method: contactor mounting). It uses a thermal bimetallic release to protect motors against overload and phase-loss conditions. This matches the majority of pump, fan, and conveyor applications in industrial panels. ## Panel fit and mounting — size S0, 85 mm deep The size S0 frame is the most common overload relay footprint in the SIRIUS family, fitting directly onto S0 contactors without additional adapter brackets. The main circuit connection uses ring cable lugs with M4 screws. The auxiliary switch is integrated, so no separate add-on block is needed for the trip/alarm signal. ## Motor power ratings and auxiliary contact capacity At 400 V AC-3e duty the relay is rated for 1.5 kW motor power; at 500 V it handles 2.2 kW; at 690 V it covers 3 kW. The maximum operating voltage is 690 V. These ratings let you match the relay to the motor nameplate without oversizing. These ratings cover the PLC input or alarm circuit draw in most control panels. ## Compliance and substance restrictions The 3RU2126-1EJ0 carries a substance prohibition date of 10/01/2009, which aligns with RoHS and REACH compliance milestones. The relay operates at 50/60 Hz and uses a Pozidriv PZ2 screwdriver tip for the terminal screws.","metaTitle":"Siemens 3RU2126-1EJ0 SIRIUS Thermal Overload Relay, Size S0","metaDescription":"Siemens 3RU2126-1EJ0 SIRIUS thermal overload relay, size S0, Class 10 trip. 85 mm depth, contactor-mount. Rated 1.5 kW at 400 V.","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","title":"3RU2126-1EJ0","Height":"85 mm","at 24 V":"2 A","at 60 V":"0.3 A","Per Pole":"1.9 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","description":"Overload relay 2.8...4.0 A Thermal For motor protection Size S0, Class 10 Contactor mounting Main circuit: Ring cable lug Auxiliary circuit: ring cable lug Manual-Automatic-Reset","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":"1.5 kW","at 480 V rated value":"4 A","at 500 V rated value":"2.2 kW","at 600 V rated value":"4 A","at 690 V rated value":"3 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":"4 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":"4 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":"5.7 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"2.8 ... 4 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/0c5b23df1811cec7a95514c591326278.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=229334&mlfb=3RU2126-1EJ0"},"ai":{"faq":[{"question":"What does the 'for message Tripped' note mean on the 3RU2126-1EJ0?","answer":"The note indicates that the integrated auxiliary switch provides a signal output when the relay trips from an overload or phase-loss condition. This N/C contact changes state to indicate the 'Tripped' status to a PLC or indicator lamp."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-1EJ0","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/3RU2126-1EJ0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}