{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU7146-4MB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU7146-4MB0","canonicalUrl":"https://aoctrl.com/siemens/3RU7146-4MB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU7146-4MB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RU7146-4MB0, Size S3 thermal overload relay, 100 A rated operational current, Class 10 trip class, screw terminals, contactor mounting.","salesMarkdown":"The thermal bimetallic design responds to motor heating, not just instantaneous current, so it tracks the actual thermal state of the windings. The relay mounts directly onto a SIRIUS S3 contactor (the same frame size), forming a compact motor starter package on the DIN rail. The front panel carries an IP20 rating — safe for finger contact in an open panel — while the terminal area is IP00, meaning the wiring zone expects enclosure protection. Screw-type terminals on both the main and auxiliary circuits accept 2× (0.5…1.5 mm²) solid or 2× (0.75…2.5 mm²) stranded, torqued to 4…6 N·m on the mains and 0.8…1.2 N·m on the auxiliaries. ## Deployment context The auxiliary contact set includes a normally-open and normally-closed pair; the DC-13 rating of 1 A at 24 V means those contacts can switch PLC inputs or relay coils in a 24 VDC control loop without derating. Mounting position is flexible: the relay can be rotated ±135° on a vertical surface or tilted ±45° front-to-back, which helps when fitting into tight enclosures or angled subpanels. A 6 mm air gap to grounded parts at the side is required — standard for 1 000 V rated insulation. The 21 W typical power loss at rated current means the enclosure's thermal budget must account for that heat, especially when multiple starters are ganged.","metaTitle":"Siemens 3RU7146-4MB0 SIRIUS Thermal Overload Relay, 100 A, C","metaDescription":"Siemens SIRIUS 3RU7146-4MB0 thermal overload relay, 100 A rated current, Class 10 trip, S3 size for contactor mounting. Active production. Sourced to order via RFQ.","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":"7 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":"21 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":"100 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":"21 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"80 ... 100 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/1d32e402878e5a2e83be0a2a988cb852.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1542630&mlfb=3RU7146-4MB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU7146-4MB0/alternatives.json"},"ai":{"faq":[{"question":"What does the Class 10 trip class mean for motor protection?","answer":"Class 10 means the relay will trip within 10 seconds at 7.2 times the current setting. This is fast enough to protect standard induction motors during a locked-rotor condition while allowing normal starting inrush — a common choice for general-purpose motor starters."},{"question":"What contactor does this relay mount to?","answer":"It mounts directly onto a SIRIUS Size S3 contactor (same frame size designation) using the contactor mounting method. No separate DIN-rail adapter is needed — the relay clips onto the contactor and connects the main circuit through the contactor's load-side terminals."},{"question":"What are the terminal specifications for wiring?","answer":"The main circuit terminals accept 2× (0.5…1.5 mm²) solid or 2× (0.75…2.5 mm²) stranded wire, torqued to 4…6 N·m. Auxiliary terminals take the same wire sizes but torque to 0.8…1.2 N·m. All terminals are screw-type."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU7146-4MB0","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/3RU7146-4MB0 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}}