{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4445-2BC44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4445-2BC44","canonicalUrl":"https://aoctrl.com/siemens/3RW4445-2BC44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4445-2BC44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4445-2BC44 soft starter, 542 A at 40 °C, 690 V insulation voltage, 50/60 Hz, inside-delta circuit, thyristor-based, display for fault signal.","salesMarkdown":"## 542 A at 40 °C — the rating that decides the motor The 3RW4445-2BC44: That derating curve means the panel ambient temperature sets the usable motor current — in a 50 °C enclosure you lose about 10 % of the headline figure. Insulation voltage is 690 V, so it sits comfortably on 400 V or 480 V systems with headroom to the rated impulse withstand. Operating frequency is 50/60 Hz — no derating needed for either. The inside-delta circuit topology reduces line current compared to a standard in-line connection — the motor windings see full voltage but the soft starter carries phase current, not line current. This matters when the cable or busbar run is already sized for a lower ampacity. ## Mounting and wiring — what fits in the panel Depth is 298 mm, width 210 mm, height 230 mm. That depth is the critical dimension for retrofit into existing enclosures — measure the back panel clearance before committing. Mounting position is flexible: vertical surface with ±90° rotation and ±22.5° tilt front/back. Screw fixing, not DIN rail — plan for drilled and tapped holes or a mounting plate. Main power connections accept stranded 70–240 mm² or busbar connection. For North American wire, the main contacts take 2/0–500 kcmil. The busbar option is preferred for high-current runs to avoid multiple parallel cables. ## Protection and diagnostics on board Motor overload protection is integrated — the soft starter models motor thermal state directly, no separate overload relay needed. Adjustable current limitation lets you set the starting current profile between 8 % and the rated current. Intrinsic device protection covers the thyristors against overtemperature and overcurrent. A display shows fault signals locally — no HMI or panel door cutout required for basic diagnostics. Clearance and creepage distances are designed for that level. ## Sourcing and lifecycle — active production, quoted per BOM Sourced through authorized distribution channels. The 542 A rating and inside-delta topology make it a direct fit for motor control centers where a VFD is overkill but a direct-on-line contactor is too harsh.","metaTitle":"Siemens 3RW4445-2BC44 SIRIUS Soft Starter, 542 A at 40 °C","metaDescription":"Siemens SIRIUS 3RW4445-2BC44 soft starter, 542 A at 40 °C, 690 V insulation, inside-delta circuit, motor overload protection. Active production.","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":"3RW4445-2BC44","Height":"230mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 400 V, 40 °C standard: 313 A, 160 kW Inside-delta: 542 A, 315 kW 200-460 V AC, 230 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5545-2HA14<<","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":"230V","at 60 Hz rated value":"230V","at 40 °C rated value":"542A","at 50 °C rated value":"485A","at 60 °C rated value":"433A","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":"400hp","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","Operating Voltage At Inside-Delta Circuit Rated Value":"200 ... 460V","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":"145W","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":"62A","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/873aea94376caedcadf5f87984c18476.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=439702&mlfb=3RW4445-2BC44"},"ai":{"faq":[{"question":"What is the 3RW4445-2BC44's current rating at different ambient temperatures?","answer":"542 A at 40 °C, 485 A at 50 °C, and 433 A at 60 °C. The derating is linear above 40 °C — budget the enclosure ambient temperature against the motor FLA."},{"question":"Does the 3RW4445-2BC44 include motor overload protection?","answer":"Yes — motor overload protection is integrated. The soft starter models the motor thermal state internally, so no separate overload relay is required in the circuit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4445-2BC44","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/3RW4445-2BC44 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}}