{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-1GJ0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-1GJ0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-1GJ0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1GJ0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-1GJ0, thermal overload relay, Class 10, size S0, rated 690 V, for contactor mounting.","salesMarkdown":"Rated for 690 V, this relay mounts directly onto a contactor (contactor mounting per), so it integrates into the motor starter stack without extra wiring or a separate enclosure. The auxiliary switch is integrated, saving a slot in the panel for a separate aux block. The Trip Class 10 is the headline spec here — it defines how fast the relay opens on a locked-rotor event. For a motor driving a pump or conveyor, Class 10 gives enough time to ride through normal starting inrush without nuisance trips, but still protects the winding from overheating during a stall. If your application needs faster protection (like on a high-inertia fan), you'd step up to Class 5 or 10A, but Class 10 covers the vast majority of standard motor starts. The auxiliary contact ratings span the common control voltages you'll find in a panel: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. At 690 V the aux contact is rated 0.75 A, so if you're switching a 690 V control circuit, keep the load under that. Power dissipation per pole is 2.2 W. In a densely packed panel with several overload relays side by side, that heat adds up — factor it into your enclosure ventilation calculation, especially if ambient hits 40 °C or higher. Size S0 is the mid-frame in the SIRIUS overload relay family — it mates with S0 contactors like the 3RT102 or 3RT103 series. Mounting position is any, which helps when you're retrofitting into a cramped enclosure and can't guarantee vertical orientation. Main circuit connections use ring cable lugs with M4 screws. The screwdriver spec is Pozidriv PZ2 with a 5–6 mm shaft diameter — if your kit only has Phillips, grab a PZ2 bit before you start; Pozidriv cam-out is different and you'll strip the head with a Phillips driver.","metaTitle":"Siemens 3RU2126-1GJ0 SIRIUS Thermal Overload Relay, Class 10","metaDescription":"Siemens 3RU2126-1GJ0 SIRIUS thermal overload relay, Class 10 trip, S0 size, 690 V rated, current production. 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":"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","at 690 V":"0.75 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":"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":"Ring cable lug connection","Temperature Compensation":"-40 ... +60 °C","MTTF with high demand rate":"2 280 a","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":"6.3 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":"6.3 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":"4.5 ... 6.3 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=144269&mlfb=3RU2126-1GJ0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2126-1GJ0/alternatives.json"},"ai":{"faq":[{"question":"What does the Trip Class 10 rating mean for my motor?","answer":"Class 10 means the relay will trip within 10 seconds at 7.2× the set current. That's fast enough to protect standard induction motors during a locked-rotor event while allowing normal inrush during starting."},{"question":"What are the auxiliary contact ratings?","answer":"The integrated auxiliary switch is rated 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, and 0.75 A at 690 V."},{"question":"What size contactor does this relay mount to?","answer":"It is size S0 and mounts directly onto S0 contactors such as the 3RT102 or 3RT103 series."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-1GJ0","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/3RU2126-1GJ0 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}}