{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA1145-4JB44-1BB4","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA1145-4JB44-1BB4","canonicalUrl":"https://aoctrl.com/siemens/3RA1145-4JB44-1BB4","factsUrl":"https://aoctrl.com/api/mcp/products/3RA1145-4JB44-1BB4","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS non-fused motor starter, Size S3, direct starter, 24 VDC control, 63 A at 480 V AC-3, Trip Class 10, snap-on 35 mm DIN rail.","salesMarkdown":"The Siemens 3RA1145-4JB44-1BB4 is a SIRIUS non-fused motor starter, Size S3, configured as a direct starter. It combines a contactor and a thermal bimetallic overload relay in a single assembly, ready to snap onto a 35 mm standard DIN rail in a vertical mounting position. Rated for AC-3 duty up to 690 V, it delivers 63 A at 480 V — enough to handle a 50 hp motor at 460/480 V or a 30 000 W load at 400 V. The control coil is 24 V, so it integrates directly into a 24 VDC control circuit without an extra power supply step-down. That is the standard for standard-duty motor starting — it protects the motor during a stall or locked-rotor condition without nuisance-tripping on a normal start. The 63 A at 480 V AC-3 rating is the headline number for motor switching. AC-3 is the duty cycle for starting and disconnecting squirrel-cage motors under load. The same part carries 61.5 A at 600 V and 37 000 W at 500 V, so it covers the common North American and European motor voltages in one package. The supplied contactor is the 3RT1044-1BB40, and the link module is 3RA1941-1BA00 — these are the internal subassemblies that make up the starter. If you are replacing only the contactor or overload block on an existing SIRIUS S3 feeder, those are the order codes to cross-reference. Wire range for the main contacts is 2.5 to 70 mm² stranded, or 2× (10 to 50 mm²) — that is a heavy lug range, sized for the 63 A feed. The enclosure clearances are specified: 90 mm upward, 10 mm forward, 10 mm downward, 12 mm at the side, and 0 mm backward, so panel layout must respect those ventilation and arc-flash gaps. For a BOM line that calls out the 3RA1145-4JB44-1BB4, the fit is confirmed: Size S3 footprint, 24 V control, Trip Class 10, and the full AC-3 current range up to 63 A at 480 V.","metaTitle":"Siemens 3RA1145-4JB44-1BB4 SIRIUS Non-Fused Motor Starter","metaDescription":"Siemens 3RA1145-4JB44-1BB4 SIRIUS non-fused motor starter, Size S3, 63 A at 480 V, 24 VDC control, Trip Class 10. Current production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"220 mm","Width":"70 mm","Height":"330 mm","Upwards":"90 mm","Forwards":"10 mm","Backwards":"0 mm","Downwards":"10 mm","Trip Class":"CLASS 10","At The Side":"12 mm","Rated Value":"24 V","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-55 ... +80 °C","Fastening Method":"snap-on fastening on 35 mm standard rail","Mounting Position":"vertical","Product Brand Name":"SIRIUS","Type Of Assignment":"2","Degree Of Pollution":"3","Product Designation":"non-fused motor starter","Size Of Load Feeder":"S3","at 230 V rated value":"15 hp","at 400 V rated value":"30 000 W","at 480 V rated value":"63 A","at 500 V rated value":"37 000 W","at 600 V rated value":"61.5 A","Design Of The Product":"direct starter","at 110/120 V rated value":"5 hp","at 200/208 V rated value":"20 hp","at 220/230 V rated value":"25 hp","at 460/480 V rated value":"50 hp","at 575/600 V rated value":"60 hp","Of The Supplied Contactor":"3RT1044-1BB40","For Main Contacts Stranded":"2.5 ... 70 mm², 2x (10 ... 50 mm²)","Of The Supplied Link Module":"3RA1941-1BA00","Size Of The Circuit-Breaker":"S3","at AC-3 rated value maximum":"690 V","Substance Prohibitance (Date)":"03/01/2017","Design Of The Overload Release":"thermal (bimetallic)","Design Of The Switching Contact":"electromechanical","Operating Frequency Rated Value":"50 ... 60 Hz","at AWG cables for main contacts":"1x (10 ... 2/0), 2x (10 ... 1/0)","Design Of The Short-Circuit Trip":"magnetic","Of The Supplied Circuit-Breakers":"3RV1041-4JA15","Product Extension Auxiliary Switch":"Yes","holding power of magnet coil at DC":"15 W","Surge Voltage Resistance Rated Value":"6 kV","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","shock resistance according to IEC 60068-2-27":"6g / 11 ms","Of The Supplied Standard Mounting Rail Adapter":"3RA1942-1AA00","at 400 V according to IEC 60947-4-1 rated value":"50 000 A","at 500 V according to IEC 60947-4-1 rated value":"50 000 A","operational current at AC-3 at 400 V rated value":"55 A","Type Of Electrical Connection For Main Current Circuit":"screw-type terminals","Mechanical Service Life (Switching Cycles) Of Contactor Typical":"10 000 000","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"819 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"45 ... 63 A","Connectable Conductor Cross-Section For Main Contacts Finely Stranded With Core End Processing":"2.5 ... 50 mm²"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$876.30","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=291109&mlfb=3RA1145-4JB44-1BB4","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RA1145-4JB44-1BB4/alternatives.json"},"ai":{"faq":[{"question":"Can 3RA1145-4JB44-1BB4 be used for reversing applications?","answer":"No. The product design is a direct starter, not a reversing starter. For reversing, you would need two contactors and a mechanical interlock — this single assembly does not include that configuration."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA1145-4JB44-1BB4","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/3RA1145-4JB44-1BB4 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}}