{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4426-3BC44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4426-3BC44","canonicalUrl":"https://aoctrl.com/siemens/3RW4426-3BC44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4426-3BC44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4426-3BC44 soft starter, 133 A at 40 °C, 230 V AC, 50/60 Hz, integrated bypass, adjustable current limitation, screw fixing, 170 x 192 x 270 mm.","salesMarkdown":"## Current ratings and thermal derating profile The 3RW4426-3BC44: This derating curve sets the real-world continuous current capacity inside a warm panel — the 133 A figure applies only at the 40 °C reference point, and the actual motor FLA must fall within the derated value at the enclosure's internal ambient. The insulation voltage rating of 690 V provides headroom above the 230 V operating level, while the operating frequency range of 50 to 60 Hz covers global line supplies without derating. ## Integrated bypass and adjustable current limit An integrated bypass contact system switches the thyristors out of the circuit once the motor reaches full speed, eliminating SCR conduction losses during continuous run. This directly reduces heat dissipation inside the panel and improves overall system efficiency compared to soft starters that keep the thyristors in circuit. Adjustable current limitation allows tuning the starting current peak between the minimum load threshold of 8% and the full rated current. For applications with light initial loads or conveyors that must not jolt, this parameter sets the acceleration torque profile. ## Mounting envelope and panel integration The 3RW4426-3BC44 measures 170 mm wide by 192 mm high by 270 mm deep, with screw-fixing mounting. Minimum clearance requirements are 100 mm upward, 75 mm downward, and 5 mm at the sides for airflow and cable bending radius. The mounting position allows vertical surface orientation with ±90° rotation and ±22.5° tilt front-to-back, giving flexibility in tight panel layouts while maintaining the derating and cooling assumptions. ## Wiring terminals and cable sizing Main current circuit connections use box terminals accepting stranded cable sizes 2x (4 to 50 mm²) or AWG 10 to 1/0 using both clamping points. The back and front clamping points each accept AWG 10 to 2/0, providing options for parallel feeds or larger single conductors. Auxiliary and control circuits terminate via spring-loaded terminals accepting solid wire 2x (0.25 to 1.5 mm²) or AWG 24 to 16. Maximum motor cable length is 500 m, which governs installation in distributed motor centres where the soft starter is remote from the load. ## Environmental and protection features Operating temperature range is up to 60 °C during operation, with storage from -25 to +80 °C. Built-in motor overload protection and intrinsic device protection are standard, with an external reset input and a display for fault signal indication. The inside-delta circuit configuration is supported for motors wired in delta during start.","metaTitle":"Siemens 3RW4426-3BC44 SIRIUS Soft Starter, 133 A, 230 V","metaDescription":"Siemens 3RW4426-3BC44 SIRIUS soft starter, active production. Rated 133 A at 40 °C, 230 V, 50/60 Hz. Integrated bypass, adjustable current limit.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"270mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"170mm","title":"3RW4426-3BC44","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 spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5526-3HA14<<","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 Auxiliary Contacts":"2x (24 ... 16)","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":"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":"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%"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/22bfaab08bd64259d6984fce500465bd.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=136989&mlfb=3RW4426-3BC44"},"ai":{"faq":[{"question":"What is the continuous current rating of 3RW4426-3BC44 at typical panel ambient?","answer":"Rated 133 A at 40 °C, but derates to 118 A at 50 °C and 102 A at 60 °C. For a panel running at 50 °C internal ambient, the motor FLA must not exceed 118 A continuous."},{"question":"Does 3RW4426-3BC44 include an internal bypass contactor?","answer":"Yes, it has an integrated bypass contact system that removes the thyristors from the circuit after start, reducing continuous power dissipation and heat in the enclosure."},{"question":"What wiring terminals does 3RW4426-3BC44 use for main and control circuits?","answer":"Main circuit connections use box terminals accepting stranded 4 to 50 mm² or AWG 10 to 1/0. Auxiliary and control circuits use spring-loaded terminals for solid 0.25 to 1.5 mm² or AWG 24 to 16."},{"question":"What clearance is needed around 3RW4426-3BC44 in a panel?","answer":"Minimum clearances are 100 mm above, 75 mm below, and 5 mm at the sides for ventilation and cable access."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4426-3BC44","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/3RW4426-3BC44 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}}