{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2126-4AC0-ZW97","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2126-4AC0-ZW97","canonicalUrl":"https://aoctrl.com/siemens/3RU2126-4AC0-ZW97","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2126-4AC0-ZW97","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU2126-4AC0-ZW97 thermal overload relay, size S0, CLASS 10, 690 V rated, spring-loaded terminals, integrated auxiliary switch with trip-signal contact.","salesMarkdown":"## Trip-signal variant — what the note means The 3RU2126-4AC0-ZW97 is a SIRIUS size S0 thermal overload relay with an integrated auxiliary contact wired to report a \"Tripped\" message. Unlike a standard 3RU2 relay where the auxiliary contacts are free for any control logic, this variant dedicates one set to the trip signal — so the PLC or HMI sees a discrete alarm the instant the relay opens on overload, without needing a separate sensing circuit. The trip signal is available at the relay terminals without additional wiring to the contactor auxiliary block. ## CLASS 10 trip curve and motor protection For higher-inertia loads like centrifuges or crushers, a CLASS 20 or CLASS 30 relay would be needed to avoid nuisance trips during start. The thermal bimetallic element compensates for ambient temperature from -40 to +60 °C, so trip accuracy holds in unconditioned enclosures or outdoor cabinets. ## Mounting and wiring — contactor snap-on Fastening method is contactor mounting — the relay snaps directly onto a SIRIUS 3RT2 contactor, eliminating DIN rail space. Dimensions are 84 mm deep × 45 mm wide × 102 mm high, the standard S0 envelope. The auxiliary screw terminals accept a 3.0 × 0.5 mm screwdriver tip. No torque tool needed on the main circuit, which speeds wiring on repetitive panel builds. Power dissipation per pole is 2.7 W — at full load the three poles dissipate about 8.1 W total. In a sealed enclosure with multiple relays ganged, this heat adds up; allow ventilation or derate if ambient exceeds 60 °C. MTTF at high demand rate is 2,280 years, supporting use in safety circuits up to SIL 2 per IEC 61508 when paired with a suitable contactor.","metaTitle":"Siemens 3RU2126-4AC0-ZW97 SIRIUS Overload Relay, CLASS 10","metaDescription":"Siemens 3RU2126-4AC0-ZW97 SIRIUS thermal overload relay, size S0, CLASS 10 trip class, with integrated auxiliary contact for trip signaling.","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","title":"3RU2126-4AC0-ZW97","Height":"102 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","Trip Class":"CLASS 10","Rated Value":"690 V","description":"Overload relay 11...16 A Thermal For motor protection Size S0, Class 10 Contactor mounting Auxiliary circuit: spring-type terminal Auxiliary circuit: spring-type terminal Manual-Automatic-Reset Multi-unit packaging Pack = 12 units","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":"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":"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":"16 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":"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":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/62dee42e89cc0c1029604cb3cf077524.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=773363&mlfb=3RU2126-4AC0-ZW97"},"ai":{"faq":[{"question":"What does the 'Tripped' message note mean on this overload relay?","answer":"The note indicates the integrated auxiliary contact is wired to signal a trip condition. When the relay opens on overload, the contact changes state — this can be wired directly to a PLC digital input or alarm panel to report the trip without additional sensing hardware."},{"question":"What is the closest alternative to 3RU2126-4AC0-ZW97 in the SIRIUS family?","answer":"The standard 3RU2126-4AC0 (without the -ZW97 suffix) is the same thermal overload relay but without the dedicated trip-signal auxiliary contact. The -ZW97 variant adds the pre-wired trip message contact; if your application does not require that dedicated signal, the base 3RU2126-4AC0 is functionally identical for motor protection."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2126-4AC0-ZW97","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/3RU2126-4AC0-ZW97 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}