{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4444-2BC36","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4444-2BC36","canonicalUrl":"https://aoctrl.com/siemens/3RW4444-2BC36","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4444-2BC36","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4444-2BC36 soft starter, 433 A at 40 °C, 690 V insulation voltage, thyristor-based, inside-delta circuit capable, screw fixing.","salesMarkdown":"## 433 A at 40 °C — the operating ceiling for full-load motor starting The Siemens 3RW4444-2BC36 SIRIUS soft starter is rated 433 A at 40 °C ambient, which sets the maximum motor full-load current it can ramp up without exceeding its thermal limit. ## Thyristor switching and inside-delta wiring Built around thyristors for the main current path, this soft starter provides controlled voltage ramp starting to limit inrush current and mechanical shock to the driven load. The inside-delta circuit connection option reduces the current through the soft starter by a factor of √3 compared to standard in-line wiring — useful when the motor current exceeds the unit's rating but the soft starter can still handle the reduced phase current. Motor overload protection is integrated, so you can omit a separate overload relay in many installations. Adjustable current limitation lets you set the start current between 8% and the unit's full rating, matching the load's breakaway torque requirement. ## Panel mounting and clearance requirements Mounting is by screw fixing onto a vertical surface, with ±90° rotation and ±22.5° tilt allowance for panel layout flexibility. The footprint is 210 mm wide by 230 mm high, and the depth is 298 mm — that depth is the dimension to check for enclosure depth clearance, especially in shallow cabinets. Ventilation and safety spacing: 100 mm clearance required upwards, 75 mm downwards, and 5 mm at the sides. These gaps keep the heat from the thyristor stack from recirculating into the control electronics. ## Field wiring and termination Main circuit wiring accepts stranded conductors from 70 to 240 mm², finely stranded from 50 to 240 mm², and AWG/kcmil from 2/0 to 500 kcmil. For busbar connection, the main current circuit uses busbar connection points rather than cable lugs — a common preference in high-current switchgear where bus runs replace individual cables. Sourced through authorized distribution channels. The unit carries pollution degree 3 per IEC 60947-4-2, suitable for industrial environments with conductive pollution.","metaTitle":"Siemens 3RW4444-2BC36 Soft Starter, 433A, SIRIUS","metaDescription":"Siemens 3RW4444-2BC36 SIRIUS soft starter, rated 433A at 40°C, 690V insulation voltage, thyristor-based, active production. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"298mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"210mm","title":"3RW4444-2BC36","Height":"230mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 575 V, 50 °C standard: 215 A, 200 hp Inside-delta: 372 A, 350 hp 400-690 V AC, 115 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5544-2HA16<<","During Storage":"-25 ... +80°C","External Reset":"Yes","Finely Stranded":"50 ... 240 mm²","lifecycle_stage":"current","During Operation":"60°C","Fastening Method":"screw fixing","Minimum Load [%]":"8%","For Main Contacts":"2/0 ... 500 kcmil","Mounting Position":"with vertical mounting surface +/-90° rotatable, with vertical mounting surface +/- 22.5° tiltable to the front and back","Product Brand Name":"SIRIUS","Degree Of Pollution":"3, acc. to IEC 60947-4-2","Product Designation":"Soft starter","Wire Length Maximum":"500m","Derating Temperature":"40°C","Inside-Delta Circuit":"Yes","at 50 Hz rated value":"115V","at 60 Hz rated value":"115V","at 40 °C rated value":"433A","at 50 °C rated value":"372A","at 60 °C rated value":"320A","For Auxiliary Contacts":"2x (24 ... 16)","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","Using The Back Clamping Point":"250 ... 500 kcmil","Insulation Voltage Rated Value":"690V","Using The Front Clamping Point":"3/0 ... 600 kcmil","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"Display","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"spring-loaded terminals","Product Component Motor Brake Output":"Yes","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 (0.25 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Evaluation Of Thermistor Motor Protection":"Yes","at standard circuit at 40 °C rated value":"160kW","at standard circuit at 50 °C rated value":"200hp","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":"3","Type Of Voltage Of The Control Supply Voltage":"AC","at inside-delta circuit at 40 °C rated value":"315kW","at inside-delta circuit at 50 °C rated value":"350hp","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":"400 ... 690V","at 690 V at standard circuit at 40 °C rated value":"250kW","contact rating of auxiliary contacts according to UL":"B300 / R300","Operating Voltage At Inside-Delta Circuit Rated Value":"400 ... 600V","Relative Negative Tolerance Of The Operating Frequency":"-10%","Relative Positive Tolerance Of The Operating Frequency":"10%","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":"110W","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":"50A","Relative Negative Tolerance Of The Operating Voltage At Inside-Delta Circuit":"-15%","Relative Positive Tolerance Of The Operating Voltage At Inside-Delta Circuit":"10%"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e8d99ab0ddc9c5714f9ca28124d0a9c8.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=268123&mlfb=3RW4444-2BC36"},"ai":{"faq":[{"question":"What is the maximum motor cable length for 3RW4444-2BC36?","answer":"The maximum wire length from the soft starter to the motor is 500 m. Beyond that, voltage drop and cable capacitance can affect the thyristor commutation and the motor terminal voltage profile."},{"question":"Does 3RW4444-2BC36 support inside-delta wiring?","answer":"Yes, it is inside-delta circuit capable. This wiring topology places the soft starter in the delta legs of a delta-connected motor, reducing the current through each thyristor pair to 58% of the motor line current — a useful option when the motor FLA exceeds the unit's 433 A rating."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4444-2BC36","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/3RW4444-2BC36 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}