{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU7146-4KB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU7146-4KB0","canonicalUrl":"https://aoctrl.com/siemens/3RU7146-4KB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU7146-4KB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU7146-4KB0 thermal overload relay, S3 size, 75 A rated operational current, Class 10 trip class, screw terminals, IP20 front / IP00 terminal area.","salesMarkdown":"## What the 75 A and Class 10 mean for motor protection The 3RU7146-4KB0 is a SIRIUS thermal overload relay rated 75 A operational current — that's the full-load motor current it's sized to protect, not a switching rating. It mounts directly onto a S3-size contactor via the contactor mounting fastening method, saving DIN rail space and keeping the power loop short. The relay is rated for AC/DC main circuits up to 1000 V at 50/60 Hz. Main terminal torque is 4 to 6 N·m; auxiliary terminals are 0.8 to 1.2 N·m — over-torquing strips the threads on the smaller auxiliary screws. Side clearance to grounded parts is 6 mm minimum. The relay is IP20 on the front face but IP00 at the terminal area — the terminals are live-touch accessible, so the panel door or a terminal cover must provide the touch protection.","metaTitle":"Siemens 3RU7146-4KB0 SIRIUS thermal overload relay, 75 A","metaDescription":"Siemens 3RU7146-4KB0 SIRIUS thermal overload relay, 75 A rated current, Class 10 trip, S3 size, IP20 front. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Depth":"140 mm","Width":"70 mm","Height":"120 mm","at 24 V":"3 A","Per Pole":"6.3 W","at 230 V":"2 A","Trip Class":"CLASS 10","On The Front":"IP20","Of The Terminal":"IP00","lifecycle_stage":"current","During Operation":"-20 ... +55 °C","During Transport":"-25 ... +70 °C","Fastening Method":"Contactor mounting","Mounting Position":"with vertical mounting surface +/-135° rotatable, with vertical mounting surface +/- 45° tiltable to the front and back","Solid Or Stranded":"2x (0.5 ... 1.5 mm²), 2x (0.75 ... 2.5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Thermal overload relay","Size Of Overload Relay":"S3","For Main Current Circuit":"screw-type terminals","power loss [W] total typical":"18.9 W","Operating Voltage Rated Value":"1 000 V","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"75 A","For Auxiliary And Control Circuit":"screw-type terminals","Relative Humidity During Operation":"0 ... 90 %","Surge Voltage Resistance Rated Value":"8 kV","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","Type Of Voltage For Main Current Circuit":"AC/DC","For Main Contacts With Screw-Type Terminals":"4 ... 6 N·m","shock resistance according to IEC 60068-2-27":"8g / 10 ms","Required Spacing For Grounded Parts At The Side":"6 mm","For Auxiliary Contacts With Screw-Type Terminals":"0.8 ... 1.2 N·m","Size Of Contactor Can Be Combined Company-Specific":"S3","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","operational current of auxiliary contacts at DC-13 at 24 V":"1 A","Arrangement Of Electrical Connectors For Main Current Circuit":"Top and bottom","insulation voltage with degree of pollution 3 at AC rated value":"1 000 V","power loss [W] for rated value of the current at AC in hot operating state":"18.9 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"57 ... 75 A","Design Of The Fuse Link For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 6 A, quick: 10 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/727d00a22c29d5fd2bf84b6879f2a997.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1542628&mlfb=3RU7146-4KB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU7146-4KB0/alternatives.json"},"ai":{"faq":[{"question":"What contactor does the 3RU7146-4KB0 mount on?","answer":"It mounts on S3-size SIRIUS contactors via the contactor mounting fastening method. The S3 size designation matches the company-specific contactor frame, so the relay clips directly onto the contactor without a separate base."},{"question":"What is the IP rating on the 3RU7146-4KB0?","answer":"IP20 on the front face, IP00 at the terminals. The terminal area is not touch-protected — the panel door or a terminal shroud must provide the safety barrier."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU7146-4KB0","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/3RU7146-4KB0 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}}