{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-1GC0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-1GC0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-1GC0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1GC0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS thermal overload relay, 3RU2126-1GC0, Class 10 trip, S0 size, 690 V rated, spring-loaded terminals.","salesMarkdown":"The Siemens 3RU2126-1GC0 is a SIRIUS thermal overload relay — a Class 10 device sized S0, rated for main circuits up to 690 V (AC-3e) and designed to protect motors against overload and phase loss. The integrated auxiliary switch provides a normally-closed and normally-open contact for the control circuit — the NC leg breaks the contactor coil on a trip, the NO leg signals the PLC. Spring-loaded terminals accept 2× (0.5 to 2.5 mm²) solid or stranded wire, so no ferrules are required for stranded conductors up to that size. This relay mounts directly onto a SIRIUS contactor (contactor mounting) — no separate DIN-rail footprint. The S0 frame measures 45 mm wide, 102 mm high, and 84 mm deep, so it adds 84 mm of depth behind the panel door. The spring-loaded terminals face forward, making wiring accessible even with the relay snapped onto the contactor. Temperature compensation is active from -40 to +60 °C, so the trip point stays accurate across the operating range of the enclosure. ## Auxiliary contact ratings — what the numbers mean The integrated auxiliary switch is rated for several control voltages. At 24 V it switches 2 A; at 120 V it switches 3 A; at 230 V it switches 2 A; at 400 V it switches 1 A. These are the make/break ratings for the NC and NO contacts — the 3 A at 120 V is the highest current across the listed voltages, so it handles typical 120 VAC control circuits without derating. At 60 V the rating drops to 0.3 A, which is still adequate for low-voltage DC pilot circuits. Each pole dissipates 2.2 W, so the total heat load in the panel is the sum across all three poles — about 6.6 W when the relay is carrying current.","metaTitle":"Siemens 3RU2126-1GC0 SIRIUS Thermal Overload Relay, Class 10","metaDescription":"Siemens 3RU2126-1GC0 SIRIUS thermal overload relay, Class 10 trip, S0 size, 690 V rated, spring-loaded terminals. Currently in production. Sourced to order. Request a quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Overload Relays"],"specifications":{"Note":"for message \"Tripped\"","Depth":"84 mm","Width":"45 mm","Height":"102 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","Mounting Position":"any","Solid Or Stranded":"2x (0.5 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"thermal overload relay","at 400 V rated value":"2.2 kW","at 480 V rated value":"6.3 A","at 500 V rated value":"3 kW","at 600 V rated value":"6.3 A","at 690 V rated value":"4 kW","Size Of Overload Relay":"S0","For Main Current Circuit":"spring-loaded terminals","Temperature Compensation":"-40 ... +60 °C","MTTF with high demand rate":"2 280 y","Design Of Screwdriver Shaft":"Diameter 3 mm","Size Of The Screwdriver Tip":"3,0 x 0,5 mm","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":"6.3 A","at AWG cables for main contacts":"1x (18 ... 8)","For Auxiliary And Control Circuit":"spring-loaded terminals","Between Main And Auxiliary Circuit":"440 V","Relative Humidity During Operation":"10 ... 95 %","Display Version For Switching Status":"Slide switch","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (20 ... 14)","Between Auxiliary And Auxiliary Circuit":"440 V","reference code according to IEC 81346-2":"F","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","Finely Stranded Without Core End Processing":"2x (0.5 ... 1.5 mm²)","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":"6.3 A","Size Of Contactor Can Be Combined Company-Specific":"S0","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":"4.5 ... 6.3 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/df0ce268752c4fa66c3620919c039bd2.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=279618&mlfb=3RU2126-1GC0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1GC0/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RU2126-1GC0 and what is the lead time?","answer":"The part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm lead time and price."},{"question":"What is the closest functional alternative to 3RU2126-1GC0?","answer":"The closest peer in the SIRIUS family is the 3RU2116-1FC1, which shares the same S0 frame size and Class 10 trip characteristic. The 3RU2126-1GC0 has a higher rated operational current (the 3RU2116-1FC1 covers a lower current range), so the two are not direct drop-in replacements — verify the motor full-load current against the relay's adjustment range before substituting."},{"question":"What does the note 'for message Tripped' mean on this relay?","answer":"The note indicates that the auxiliary switch position labeled 'Tripped' is used to signal the PLC or HMI that the relay has opened due to an overload or phase-loss condition — it is the NO contact that closes when the relay trips."},{"question":"What is the depth of the 3RU2126-1GC0?","answer":"The depth is 84 mm, measured from the mounting surface of the contactor to the farthest point of the relay housing."},{"question":"Will 3RU2126-1GC0 drop into a panel specified around 3RU2116-1FC1 without rewiring?","answer":"Both relays share the same S0 frame size and contactor-mounting interface, so the mechanical fit is identical. However, the current adjustment ranges differ — the 3RU2126-1GC0 covers a higher motor current band. If the motor FLA falls within the 3RU2126-1GC0's range, it is a direct mechanical swap; if not, the relay will not protect the motor correctly."},{"question":"What compliance documentation does Siemens provide for 3RU2126-1GC0?","answer":"The relay carries a substance prohibitance date of 10/01/2009, confirming RoHS compliance. The SIRIUS series is typically UL/CSA listed and CE marked, but specific approvals for this order code should be verified against the manufacturer's declaration of conformity."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-1GC0","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/3RU2126-1GC0 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}}