{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-1FJ0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-1FJ0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-1FJ0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1FJ0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS thermal overload relay, 3RU2126-1FJ0, Size S0, Trip Class 10, rated 690 V, 50-60 Hz, contactor-mount, with integrated auxiliary switch.","salesMarkdown":"Rated for 690 V and 50-60 Hz operation, it mounts directly onto a contactor (fastening method: contactor mounting), saving panel space versus a standalone enclosure. The thermal release design compensates for ambient temperature between -40 and +60 °C, so the trip point stays accurate across the enclosure's internal heat rise. Motor power ratings it can protect: 1.5 kW at 400 V, 2.2 kW at 500 V, and 4 kW at 690 V. The auxiliary switch is integrated — no add-on block needed for the trip-indication signal. Size S0 means it fits the standard S0 contactor footprint — direct snap-on or screw-clamp mounting to the contactor, no additional DIN-rail bracket needed. The ring-cable-lug connection for the main circuit handles M4 ring terminals. Mounting position is any, so horizontal or vertical panel layouts work without derating the trip curve. Dimensions: 45 mm wide × 85 mm high × 85 mm deep — fits within a standard 45 mm module slot. The auxiliary switch uses a Pozidriv PZ2 screwdriver tip with a 5-6 mm shaft diameter. ## Auxiliary contact ratings and the 'Tripped' message The integrated auxiliary switch carries the trip-indication signal. Its contact ratings vary by voltage: 2 A at 24 V AC, 3 A at 120 V AC, 2 A at 230 V AC, 1 A at 400 V AC, and 0.22 A at 125 V DC. The Note for message 'Tripped' on the component line refers to the state when the relay has operated — the auxiliary contact changes state to signal a trip condition to the PLC or annunciator. Operating temperature range: -40 to +70 °C. Storage and transport: -55 to +80 °C. Temperature compensation active from -40 to +60 °C. The substance prohibition date of 10/01/2009 aligns with RoHS compliance (lead-free and other restricted substances). MTTF with high demand rate: 2,280 years.","metaTitle":"Siemens 3RU2126-1FJ0 SIRIUS Thermal Overload Relay, Class 10","metaDescription":"Siemens 3RU2126-1FJ0 SIRIUS thermal overload relay, Size S0, Trip Class 10, 690 V rated, contactor-mount. Current lifecycle: active. Quoted to order.","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":"1.5 kW","at 480 V rated value":"5 A","at 500 V rated value":"2.2 kW","at 600 V rated value":"5 A","at 690 V rated value":"4 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":"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":"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":"3.5 ... 5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/ca98f45927e74a8faa814c8f4da8b71a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=187567&mlfb=3RU2126-1FJ0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1FJ0/alternatives.json"},"ai":{"faq":[{"question":"What is the 3RU2126-1FJ0's 'Note for message Tripped'?","answer":"The note indicates the state when the thermal overload relay has operated — the integrated auxiliary switch changes state to signal a trip condition."},{"question":"What are the motor power ratings for the 3RU2126-1FJ0?","answer":"It protects motors rated 1.5 kW at 400 V, 2.2 kW at 500 V, and 4 kW at 690 V, all at 50-60 Hz."},{"question":"How does the 3RU2126-1FJ0 compare to the 3RU2116-1FC1?","answer":"Both are SIRIUS S0-frame thermal overload relays with Class 10 trip curves. The 3RU2126-1FJ0 is the higher-current variant in the same physical footprint — it drops into the same contactor mounting and panel cutout without rewiring, but the current setting range differs. Verify the motor FLA falls within the 3RU2126-1FJ0's adjustment range before substituting."},{"question":"Where can I buy the 3RU2126-1FJ0 and get current pricing?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm quote."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-1FJ0","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/3RU2126-1FJ0 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}}