{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RU2146-4KB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RU2146-4KB0","canonicalUrl":"https://aoctrl.com/siemens/3RU2146-4KB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RU2146-4KB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS thermal overload relay, 3RU2146-4KB0, Size S3, CLASS 10, 37 kW at 400 V, screw-type terminals, contactor mounting.","salesMarkdown":"If you are protecting a motor that starts hard (high-inertia load, long acceleration), CLASS 10 may be too fast — but for pumps, fans, and compressors on a typical 400 V line, this is the correct class. At 400 V it is rated for 37 kW motor load; at 500 V that climbs to 45 kW, and at 690 V to 55 kW. The corresponding current ratings are 65 A at 480 V and 62 A at 600 V — so the relay is sized for the motor full-load current, not the supply voltage alone. If your motor nameplate says 37 kW at 400 V, this relay covers it. The auxiliary contact ratings cover 2 A at 24 V and 230 V, 3 A at 120 V, and 0.75 A at 690 V — enough to signal a trip to the PLC or annunciator without an interposing relay. Mounts directly onto the contactor — no DIN rail required, no extra bracket. The fastening method is contactor mounting, using M8 bolts for the main circuit. The screwdriver drive is a 4 mm hexagon socket — keep that bit in your panel-building kit. Temperature compensation is active from -40 to +60 °C — so the trip curve stays accurate across the working range. RoHS compliance date is 03/01/2017, meaning it meets the substance restrictions in effect from that date.","metaTitle":"Siemens 3RU2146-4KB0 SIRIUS thermal overload relay, CLASS 10","metaDescription":"Siemens 3RU2146-4KB0 SIRIUS thermal overload relay, CLASS 10, 37 kW at 400 V. Size S3, screw terminals, contactor-mount. 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":"125 mm","Solid":"2x (2.5 ... 16 mm²)","Width":"70 mm","Height":"105 mm","at 24 V":"2 A","at 60 V":"0.3 A","Per Pole":"6.3 W","Stranded":"2x (6 ... 16 mm²), 2x (10 ... 50 mm²), 1x (10 ... 70 mm²)","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":"M8","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":"37 kW","at 480 V rated value":"65 A","at 500 V rated value":"45 kW","at 600 V rated value":"62 A","at 690 V rated value":"55 kW","Size Of Overload Relay":"S3","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-40 ... +60 °C","Design Of Screwdriver Shaft":"Hexagonal socket","Size Of The Screwdriver Tip":"4 mm hexagon socket","at AC-3e rated value maximum":"1 000 V","Substance Prohibitance (Date)":"03/01/2017","Design Of The Auxiliary Switch":"integrated","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"75 A","at AWG cables for main contacts":"2x (10 ... 1/0), 1x (10 ... 2/0)","For Auxiliary And Control Circuit":"screw-type terminals","Between Main And Auxiliary Circuit":"440 V","Relative Humidity During Operation":"10 ... 95 %","With Type Of Assignment 2 Required":"gG: 160 A","Display Version For Switching Status":"Slide switch","For Main Contacts For Ring Cable Lug":"4.5 ... 6 N·m","Surge Voltage Resistance Rated Value":"8 kV","With Type Of Coordination 1 Required":"gG: 250 A","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":"4.5 ... 6 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":"75 A","Size Of Contactor Can Be Combined Company-Specific":"S3","Outer Diameter Of The Usable Ring Cable Lug Maximum":"19 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":"1 000 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":"18.9 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"57 ... 75 A","Design Of The Miniature Circuit Breaker For Short-Circuit Protection Of The Auxiliary Switch Required":"6A (SCC less than equal to 0.5 kA; U less than equal to 260V)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$73.66","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/01db8b3c9f7e37317743fc122465bf09.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=630107&mlfb=3RU2146-4KB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RU2146-4KB0/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RU2146-4KB0?","answer":"We source and quote this part to order against an RFQ. Availability and current pricing are confirmed at quote time."},{"question":"What is the trip class of 3RU2146-4KB0?","answer":"It is CLASS 10, meaning it will trip within 10 seconds at 7.2× the set current — the standard match for across-the-line motor starting."},{"question":"Does 3RU2146-4KB0 mount on a DIN rail?","answer":"No, it mounts directly onto the contactor using M8 bolts — no DIN rail or bracket needed."},{"question":"What motor power does 3RU2146-4KB0 cover at 400 V?","answer":"It is rated for 37 kW at 400 V, 45 kW at 500 V, and 55 kW at 690 V."},{"question":"What compliance documentation does 3RU2146-4KB0 have?","answer":"RoHS compliance date is 03/01/2017. The relay operates from -40 to +70 °C and stores from -55 to +80 °C."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RU2146-4KB0","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/3RU2146-4KB0 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}}