{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4426-1BC34","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4426-1BC34","canonicalUrl":"https://aoctrl.com/siemens/3RW4426-1BC34","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4426-1BC34","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4426-1BC34 soft starter, 133 A at 40 °C, 690 V insulation voltage, 50/60 Hz, integrated bypass, inside-delta circuit, screw-type terminals.","salesMarkdown":"The 3RW4426-1BC34: That 40 °C figure is the baseline — if your panel ambient runs hotter, the continuous current ceiling drops by about 11 % per 10 °C rise. For a motor with a 125 A FLA, this starter has headroom at 40 °C but gets tight at 50 °C unless the load is intermittent. The operating frequency is 50/60 Hz, so it works on either line frequency without adjustment. ## Integrated bypass and inside-delta wiring This soft starter includes an integrated bypass contact system, meaning the thyristors are shorted out once the motor is up to speed. That eliminates continuous heat dissipation in the power semiconductors during run — the bypass carries the full load current, not the SCRs. It supports inside-delta circuit configuration, which lets you connect the soft starter in the delta leg of a six-lead motor. Inside-delta wiring reduces the current through the starter to 58 % of the line current, effectively extending the current range of the unit for a given motor FLA. ## Protection and control features Motor overload protection is built in, along with intrinsic device protection that guards the thyristors against overtemperature and phase imbalance. Adjustable current limitation lets you set the starting current between 0 and the rated value — useful for limiting inrush on weak supply lines or for gentle starts on conveyors. The minimum load threshold is 8 % of the rated current, so it can start lightly loaded motors without dropping out. External reset input is provided for remote fault recovery, and the display shows fault codes directly on the unit. ## Mounting and panel integration Dimensions are 170 mm wide, 192 mm high, and 270 mm deep. Mounting position allows vertical surface with +/-90° rotation and +/-22.5° tilt front-to-back, giving flexibility in tight cabinets. Clearance requirements: 100 mm above, 75 mm below, and 5 mm at the sides. The side clearance is minimal, but the vertical clearance is substantial — plan for it in the cabinet layout to maintain airflow for the derating curve. Main circuit terminals are box terminals accepting 2x (4... 50 mm²) stranded or 2x (10... 1/0) AWG using both clamping points. Maximum wire length to the motor is 500 m — beyond that, voltage drop and cable capacitance may affect operation. ## Environmental and compliance ratings Pollution degree 3 per IEC 60947-4-2, meaning it's rated for conductive pollution environments typical in industrial panels. Operating temperature range is up to 60 °C ambient; storage range is -25 to +80 °C.","metaTitle":"Siemens 3RW4426-1BC34 SIRIUS Soft Starter, 133 A, 690 V","metaDescription":"Siemens 3RW4426-1BC34 SIRIUS soft starter, 133 A at 40 °C, 690 V insulation voltage. Integrated bypass, inside-delta capable, active production.","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":"3RW4426-1BC34","Height":"192mm","Upwards":"100mm","Stranded":"2x (4 ... 50 mm²)","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 460 V, 50 °C standard: 68 A, 50 hp Inside-delta: 118 A, 75 hp 200-460 V AC, 115 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":"115V","at 60 Hz rated value":"115V","at 40 °C rated value":"133A","at 50 °C rated value":"118A","at 60 °C rated value":"102A","For Auxiliary Contacts":"2x (20 ... 14)","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","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%","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":"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":"$3,554.73","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/12749d66e5fa274bbaf777a5561128ce.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=243240&mlfb=3RW4426-1BC34"},"ai":{"faq":[{"question":"What is the maximum motor cable length for the 3RW4426-1BC34?","answer":"The maximum wire length to the motor is 500 m. Beyond that, voltage drop and cable charging current may interfere with the soft starter's operation."},{"question":"Does the 3RW4426-1BC34 include a bypass contactor?","answer":"Yes, it has an integrated bypass contact system. Once the motor reaches full speed, the thyristors are bypassed, eliminating continuous heat dissipation in the semiconductors."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4426-1BC34","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/3RW4426-1BC34 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}}