{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-4NJ0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-4NJ0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-4NJ0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4NJ0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-4NJ0 thermal overload relay, CLASS 10, S0 frame, 690 V rated, contactor-mount, 85 x 45 x 85 mm.","salesMarkdown":"The relay mounts directly onto a contactor via the contactor-mounting fastening method, eliminating the need for separate panel wiring between the two devices. It is sized in the S0 frame, which determines the physical envelope and the range of contactors it mates with. At 400 V it is rated for 15 kW motor output; at 500 V for 18.5 kW; at 690 V for 22 kW. These are the values that govern real motor protection sizing, not the headline current alone. The auxiliary contact integrated into the relay is rated for switching at various control voltages: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These ratings cover the typical PLC input or contactor coil signal that the trip message drives. Mounts in any position, directly to the contactor — no DIN-rail bracket needed for the relay itself, though the contactor typically snaps onto a DIN rail. The main circuit connection uses ring cable lugs (M4 screw); the auxiliary circuit uses the integrated screw terminals with a Pozidriv PZ2 tip, 5–6 mm shaft diameter. Substance compliance per RoHS is indicated by a substance-prohibitance date of 10/01/2009, confirming the part meets the EU RoHS directive. No separate UL or CSA listing is recorded in the available data, but the SIRIUS family typically carries CE and UKCA for the European market.","metaTitle":"Siemens 3RU2126-4NJ0 SIRIUS thermal overload relay, CLASS 10","metaDescription":"Siemens 3RU2126-4NJ0 SIRIUS thermal overload relay, CLASS 10 trip, S0 frame, 690 V rated, contactor-mount. Current-production part, sourced to order via 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":"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":"Contactor mounting","For Main Contacts":"M4","Mounting Position":"any","Product Brand Name":"SIRIUS","Product Designation":"thermal overload relay","at 400 V rated value":"15 kW","at 480 V rated value":"28 A","at 500 V rated value":"18.5 kW","at 600 V rated value":"28 A","at 690 V rated value":"22 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":"28 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":"28 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":"9.6 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"23 ... 28 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=254778&mlfb=3RU2126-4NJ0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4NJ0/alternatives.json"},"ai":{"faq":[{"question":"What does the 'Note for message Tripped' mean?","answer":"The relay carries a note indicating that the auxiliary contact position signals a 'Tripped' state — this is the normally-open (or normally-closed) contact that changes state when the thermal overload releases, providing a feedback signal to a PLC or indicator lamp."},{"question":"What are the physical dimensions of the 3RU2126-4NJ0?","answer":"Depth 85 mm, width 45 mm, height 85 mm. It mounts directly to a contactor, so the overall panel footprint depends on the contactor it mates with."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-4NJ0","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/3RU2126-4NJ0 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}}