{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-4AB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-4AB0","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-4AB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4AB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-4AB0 thermal overload relay, size S0, CLASS 10 trip class, 690 V rated, screw-type terminals, contactor mounting.","salesMarkdown":"## What the CLASS 10 trip means for your motor The 3RU2126-4AB0: That's the right speed for standard induction motor starts where the inrush doesn't linger; if you're starting high-inertia loads that need a longer acceleration ramp, you'd want a CLASS 20 or 30 relay instead. ## Mounting and wiring — what fits where This is a size S0 relay that mounts directly onto the contactor — no DIN rail bracket needed. The fastening method is contactor mounting, so it clicks onto the matching SIRIUS contactor and shares the same busbar connection. Screwdriver tip is Pozidriv PZ2, shaft diameter 5 to 6 mm. If you're replacing a 3RV6021-4DA10 in an existing panel, check the contactor interface — the 3RU2126-4AB0 is a size S0 relay that mounts on SIRIUS contactors, while the 3RV6021 series uses a different mounting interface. Physical swap without rewiring depends on the contactor model already in the panel.","metaTitle":"Siemens 3RU2126-4AB0 SIRIUS Overload Relay, CLASS 10, 690 V","metaDescription":"Siemens 3RU2126-4AB0 SIRIUS thermal overload relay, CLASS 10 trip, 690 V rated, size S0. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Overload Relays"],"specifications":{"Note":"for message \"Tripped\"","Depth":"85 mm","Width":"45 mm","title":"3RU2126-4AB0","Height":"85 mm","at 24 V":"2 A","at 60 V":"0.3 A","Per Pole":"2.7 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","description":"Overload relay 11...16 A Thermal For motor protection Size S0, Class 10 Contactor mounting Main circuit: Screw Auxiliary circuit: Screw 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","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"thermal overload relay","at 400 V rated value":"7.5 kW","at 480 V rated value":"16 A","at 500 V rated value":"7.5 kW","at 600 V rated value":"16 A","at 690 V rated value":"11 kW","Size Of Overload Relay":"S0","For Main Current Circuit":"screw-type terminals","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":"16 A","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","For Auxiliary And Control Circuit":"screw-type 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 ... 16), 2x (18 ... 14)","Of The Auxiliary And Control Contacts":"M3","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","For Main Contacts With Screw-Type Terminals":"2 ... 2.5 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","For Auxiliary Contacts With Screw-Type Terminals":"0.8 ... 1.2 N·m","operational current at AC-3e at 400 V rated value":"16 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":"8.1 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"11 ... 16 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$28.61","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/28994259765b6eb21e85f81ec3b530b7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=26875&mlfb=3RU2126-4AB0"},"ai":{"faq":[{"question":"What does the note 'for message Tripped' mean on this relay?","answer":"The note indicates that the auxiliary contact position changes to signal a tripped state — it's the relay's way of communicating an overload condition back to the control system, typically through a PLC input or indicator light."},{"question":"Can I order 3RU2126-4AB0 and what's the lead time?","answer":"This relay is quoted to order against your BOM quantity."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-4AB0","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/3RU2126-4AB0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}