{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4426-1BC44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4426-1BC44","canonicalUrl":"https://aoctrl.com/siemens/3RW4426-1BC44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4426-1BC44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4426-1BC44 soft starter, 133 A at 40 °C, 230 V AC, 50/60 Hz, 3-phase, integrated bypass, screw terminals, IP20.","salesMarkdown":"## Current derating and thermal budget The 3RW4426-1BC44: The derating temperature threshold is 40 °C; above that, the thyristor stack and integrated bypass contact system share the thermal load, but the bypass carries the steady-state current once the motor is up to speed. Minimum load is 8 % of the rated current — below that the soft starter may not reliably detect the motor current zero-cross for thyristor gating, so verify the no-load current of the driven motor stays above that floor. ## Wiring and termination Main power circuit uses box terminals accepting 2x (4 … 50 mm²) stranded or 2x (10 … 1/0 AWG) using both clamping points; the front and back clamping points each accept 10 … 2/0 AWG. Maximum motor cable length is 500 m — longer runs increase charging current and may cause nuisance overcurrent trips during start. ## Mounting and clearance Dimensions are 192 mm high, 170 mm wide, 270 mm deep. Fastening is screw fixing to the mounting surface. The mounting position allows vertical surface mounting with ±90° rotation and ±22.5° tilt front-to-back. Clearance requirements: 100 mm upwards, 75 mm downwards, 5 mm at the sides — the upward clearance is critical for convection cooling of the thyristor heatsink. ## Inside-delta and adjustable current limit Inside-delta circuit connection is supported — this reduces the soft starter current rating requirement to 58 % of the motor full-load current, allowing a smaller unit for delta-connected motors. Adjustable current limitation lets the user set the start current between the minimum load threshold and the device rated current, which is useful for limiting supply voltage dip during acceleration of high-inertia loads.","metaTitle":"Siemens 3RW4426-1BC44 SIRIUS Soft Starter, 133 A, 230 V","metaDescription":"Siemens 3RW4426-1BC44 SIRIUS soft starter, 133 A at 40 °C, 230 V, 50/60 Hz. Active production, available to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"270mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"170mm","title":"3RW4426-1BC44","Height":"192mm","Upwards":"100mm","Stranded":"2x (4 ... 50 mm²)","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 400 V, 40 °C standard: 77 A, 37 kW Inside-delta: 133 A, 75 kW 200-460 V AC, 230 V AC Screw terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5526-1HA14<<","During Storage":"-25 ... +80°C","External Reset":"Yes","lifecycle_stage":"current","During Operation":"60°C","Fastening Method":"screw fixing","Minimum Load [%]":"8%","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":"133A","at 50 °C rated value":"118A","at 60 °C rated value":"102A","For Main Current Circuit":"box terminal","Motor Overload Protection":"Yes","Using Both Clamping Points":"2x (10 ... 1/0)","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Using The Back Clamping Point":"10 ... 2/0","Insulation Voltage Rated Value":"690V","Using The Front Clamping Point":"10 ... 2/0","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"Display","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"screw-type 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","for AWG cables for auxiliary contacts":"2x (20 ... 14)","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":"Yes","at standard circuit at 40 °C rated value":"37kW","at standard circuit at 50 °C rated value":"50hp","Finely Stranded Without Core End Processing":"2x (4 ... 35 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":"75kW","at inside-delta circuit at 50 °C rated value":"75hp","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":"45W","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":"15A","Relative Negative Tolerance Of The Operating Voltage At Inside-Delta Circuit":"-15%","Relative Positive Tolerance Of The Operating Voltage At Inside-Delta Circuit":"10%","at AWG cables for auxiliary contacts finely stranded with core end processing":"2x (20 ... 16)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$3,249.60","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/dbbea93d3e574cebb2002b2070324a47.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=208305&mlfb=3RW4426-1BC44"},"ai":{"faq":[{"question":"Does the 3RW4426-1BC44 support inside-delta wiring?","answer":"Yes, inside-delta circuit connection is supported, which allows a smaller soft starter rating for delta-connected motors."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4426-1BC44","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/3RW4426-1BC44 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}}