{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4076-6BB44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4076-6BB44","canonicalUrl":"https://aoctrl.com/siemens/3RW4076-6BB44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4076-6BB44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS soft starter, size S12, 3RW4076-6BB44, rated 432 A at 40 °C, 385 A at 50 °C, 335 A at 60 °C, 50/60 Hz, screw fixing, busbar connection.","salesMarkdown":"The Siemens 3RW4076-6BB44 is a SIRIUS soft starter in size S12, designed to ramp up and protect three-phase induction motors in industrial control panels. It delivers 432 A at 40 °C, derating to 385 A at 50 °C and 335 A at 60 °C — the 40 °C figure is the one to size against for most enclosed panels. It includes motor overload protection and adjustable current limitation, so you can set the start current to match the load without an external overload relay. ## Mounting and wiring in the panel Mounts via screw fixing — no DIN-rail clip, so plan for direct panel mounting with the vertical surface orientation. The mounting position allows +/-10° rotation (without fan) or +/-90° with an additional fan, which matters for tight enclosures where airflow dictates orientation. Main circuit connection is busbar, accepting stranded 70–240 mm² or finely stranded 50–240 mm². Auxiliary contacts take 2x (0.5–2.5 mm²) solid. Clearance: 100 mm above, 75 mm below, 5 mm at the sides — the side gap is tight, so keep cable ducts and other devices out of that zone. The 432 A rating at 40 °C is the headline number, but the derated values at 50 °C (385 A) and 60 °C (335 A) are what govern in a warm enclosure or near other heat sources. The 20% minimum load means it needs at least 20% of the rated current to operate correctly — fine for most motors, but check if you are soft-starting a very small motor on a large unit. The operating frequency covers 50–60 Hz, common for global motor bases.","metaTitle":"Siemens 3RW4076-6BB44 SIRIUS Soft Starter, 432A at 40°C","metaDescription":"Siemens 3RW4076-6BB44 SIRIUS soft starter, size S12, rated 432A at 40°C. Active production. Screw fixing, busbar connection. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"278mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"160mm","title":"3RW4076-6BB44","Height":"230mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter S12 432 A, 250 kW/400 V, 40 °C 200-460 V AC, 230 V AC Screw terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5076-6AB14<<","During Storage":"-40 ... +80°C","External Reset":"Yes","Finely Stranded":"50 ... 240 mm²","lifecycle_stage":"current","During Operation":"-25 ... +60°C","Fastening Method":"screw fixing","Minimum Load [%]":"20%","For Main Contacts":"2/0 ... 500 kcmil","Mounting Position":"With additional fan: With vertical mounting surface +/-90° rotatable, with vertical mounting surface +/- 22.5° tiltable to the front and back Without additional fan: With vertical mounting surface +/-10° rotatable, with vertical mounting surface +/- 10° t","Product Brand Name":"SIRIUS","Degree Of Pollution":"3, acc. to IEC 60947-4-2","Product Designation":"Soft starter","Wire Length Maximum":"300m","Derating Temperature":"40°C","Inside-Delta Circuit":"No","at 50 Hz rated value":"230V","at 60 Hz rated value":"230V","at 40 °C rated value":"432A","at 50 °C rated value":"385A","at 60 °C rated value":"335A","For Auxiliary Contacts":"2x (20 ... 14)","For Main Current Circuit":"busbar connection","Motor Overload Protection":"Yes","Using Both Clamping Points":"min. 2x 2/0, max. 2x 500 kcmil","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Size Of Engine Control Device":"S12","Using The Back Clamping Point":"250 ... 500 kcmil","Insulation Voltage Rated Value":"600V","Using The Front Clamping Point":"3/0 ... 600 kcmil","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"red","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"screw-type terminals","Product Component Motor Brake Output":"No","during storage according to IEC 60721":"1K6 (only occasional condensation), 1C2 (no salt mist), 1S2 (sand must not get inside the devices), 1M4","reference code according to EN 61346-2":"Q","during operation according to IEC 60721":"3K6 (no formation of ice, no condensation), 3C3 (no salt mist), 3S2 (sand must not get into the devices), 3M6","during transport according to IEC 60721":"2K2, 2C1, 2S1, 2M2 (max. fall height 0.3 m)","Finely Stranded With Core End Processing":"2x (0.5 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Evaluation Of Thermistor Motor Protection":"No","at standard circuit at 40 °C rated value":"250kW","at standard circuit at 50 °C rated value":"300hp","Finely Stranded Without Core End Processing":"min. 2x 50 mm², max. 2x 185 mm²","number of CO contacts for auxiliary contacts":"1","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"2","Type Of Voltage Of The Control Supply Voltage":"AC","Control Supply Voltage Frequency 1 Rated Value":"50Hz","Control Supply Voltage Frequency 2 Rated Value":"60Hz","Installation Altitude At Height Above Sea Level":"5 000m","continuous operating current [% of Ie] at 40 °C":"115%","Operating Voltage At Standard Circuit Rated Value":"200 ... 460V","contact rating of auxiliary contacts according to UL":"B300 / R300","Relative Negative Tolerance Of The Operating Frequency":"-10%","Relative Positive Tolerance Of The Operating Frequency":"10%","For Auxiliary Contacts Finely Stranded With Core End Processing":"2x (20 ... 16)","Relative Negative Tolerance Of The Control Supply Voltage Frequency":"-10%","Relative Positive Tolerance Of The Control Supply Voltage Frequency":"10%","Relative Negative Tolerance Of The Operating Voltage At Standard Circuit":"-15%","Relative Positive Tolerance Of The Operating Voltage At Standard Circuit":"10%","power loss [W] at operational current at 40 °C during operation typical":"165W","relative negative tolerance of the control supply voltage at AC at 50 Hz":"-15%","relative negative tolerance of the control supply voltage at AC at 60 Hz":"-15%","relative positive tolerance of the control supply voltage at AC at 50 Hz":"10%","relative positive tolerance of the control supply voltage at AC at 60 Hz":"10%","Adjustable Motor Current For Motor Overload Protection Minimum Rated Value":"207A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$3,034.00 – $4,263.39","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/cc1f531e856fca6c4f73d407bafee574.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=283903&mlfb=3RW4076-6BB44"},"ai":{"faq":[{"question":"What are the key current ratings for this soft starter?","answer":"Rated 432 A at 40 °C, 385 A at 50 °C, and 335 A at 60 °C. The 40 °C figure is the base rating; use the derated values for warm enclosure environments."},{"question":"What mounting method does this soft starter use?","answer":"Screw fixing — it does not snap onto a DIN rail. Mount on a vertical surface with the orientation limits described: +/-10° rotation without fan, +/-90° with an additional fan."},{"question":"What wire sizes does the main circuit accept?","answer":"The main circuit uses busbar connection. It accepts stranded 70–240 mm² or finely stranded 50–240 mm². For auxiliary contacts, use solid 2x (0.5–2.5 mm²)."},{"question":"Does this soft starter include motor overload protection?","answer":"Yes, it has integrated motor overload protection and adjustable current limitation, so you can set the start current without an external overload relay."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4076-6BB44","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/3RW4076-6BB44 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}