{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4026-2BB04","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4026-2BB04","canonicalUrl":"https://aoctrl.com/siemens/3RW4026-2BB04","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4026-2BB04","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4026-2BB04 soft starter, size S0, 25 A rated current at 40 °C, 600 V insulation voltage, integrated bypass contact system, spring-loaded terminals.","salesMarkdown":"## What the 25 A rating means on a hot mill floor The 3RW4026-2BB04: Derate to 23 A at 50 °C and 21 A at 60 °C. In a steel mill cabinet pulling radiant heat from the rolls, that 60 °C ceiling is where the part survives; the 21 A limit is the one to budget for the motor nameplate. Insulation voltage is rated 600 V, matching IEC 60947-4-2 pollution degree 3 — meaning it holds up in the conductive dust and humidity of a rolling mill electrical room without tracking. ## Integrated bypass and spring terminals — panel wiring reality The integrated bypass contact system pulls the thyristors out of the circuit after start, so the 25 A rating is for the start duty only — no continuous heat sink burden on the semiconductors. Motor overload protection is built in, with adjustable current limitation to dial in the start ramp. Main and auxiliary/control circuits both terminate on spring-loaded terminals — no screw torque to verify, no loosening under vibration. Frame size S0 — 45 mm wide, 150 mm tall, 155 mm deep. Screw and snap-on mounting to DIN rail; the 45 mm width leaves room for a contactor and overload alongside in a standard 600 mm enclosure. ## Active production — sourcing posture Lifecycle stage is current — Siemens still produces this order code. ## Mounting position and clearance for heat With the additional fan, the unit mounts on a vertical surface rotatable +/-90° and tiltable +/-22.5° front/back. Without the fan, rotation is limited to +/-10°. Clearance: 60 mm upward, 40 mm downward, 15 mm at the sides — respect these for natural convection cooling, especially at the 60 °C ambient limit.","metaTitle":"Siemens 3RW4026-2BB04 SIRIUS Soft Starter, 25 A, 600 V","metaDescription":"Siemens 3RW4026-2BB04 SIRIUS soft starter, 25 A at 40 °C, 600 V insulation, S0 frame. Active production, quoted to order. Integrated bypass, spring terminals.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Soft Starters"],"specifications":{"Depth":"155mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"45mm","title":"3RW4026-2BB04","Height":"150mm","Upwards":"60mm","Downwards":"40mm","Thyristors":"Yes","At The Side":"15mm","description":"SIRIUS soft starter S0 25 A, 11 kW/400 V, 40 °C 200-480 V AC, 24 V AC/DC spring-type terminals","During Storage":"-40 ... +80°C","External Reset":"Yes","lifecycle_stage":"current","During Operation":"-25 ... +60°C","Fastening Method":"screw and snap-on mounting","Minimum Load [%]":"20%","For Main Contacts":"16 ... 10, 1x 8","Mounting Position":"With additional fan: With vertical mounting surface +/-90° rotatable, with vertical mounting surface +/- 22.5° tiltable to the front and back Without additional fan: With vertical mounting surface +/-10° rotatable, with vertical mounting surface +/- 10° t","Product Brand Name":"SIRIUS","Degree Of Pollution":"3, acc. to IEC 60947-4-2","Product Designation":"Soft starter","Wire Length Maximum":"300m","Derating Temperature":"40°C","Inside-Delta Circuit":"No","at 50 Hz rated value":"24V","at 60 Hz rated value":"24V","at 40 °C rated value":"25A","at 50 °C rated value":"23A","at 60 °C rated value":"21A","For Auxiliary Contacts":"2x (24 ... 14)","For Main Current Circuit":"spring-loaded terminals","Motor Overload Protection":"Yes","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Size Of Engine Control Device":"S0","Insulation Voltage Rated Value":"600V","Using The Front Clamping Point":"1x 8, 2x (16 ... 10)","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"red","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"spring-loaded terminals","Product Component Motor Brake Output":"No","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":"No","at standard circuit at 40 °C rated value":"11kW","at standard circuit at 50 °C rated value":"15hp","control supply voltage 1 at DC rated value":"24V","number of CO contacts for auxiliary contacts":"1","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"2","Type Of Voltage Of The Control Supply Voltage":"AC/DC","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 ... 480V","contact rating of auxiliary contacts according to UL":"B300 / R300","Relative Negative Tolerance Of The Operating Frequency":"-10%","Relative Positive Tolerance Of The Operating Frequency":"10%","relative negative tolerance of the control supply voltage at DC":"-20%","relative positive tolerance of the control supply voltage at DC":"20%","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":"8W","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":"10A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/133f12bf5954753d06697cfb98237e99.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=378692&mlfb=3RW4026-2BB04"},"ai":{"faq":[{"question":"What is the maximum wire length for the 3RW4026-2BB04?","answer":"The maximum wire length to the motor is 300 m. For longer runs, factor in voltage drop and reflected wave effects on the thyristor stack."},{"question":"Does the 3RW4026-2BB04 have an integrated bypass?","answer":"Yes, the integrated bypass contact system is standard. After the start ramp completes, the bypass closes and the thyristors are shorted — no external bypass contactor needed, and no continuous heat dissipation from the semiconductors."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4026-2BB04","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/3RW4026-2BB04 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}