{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4028-1BB15","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4028-1BB15","canonicalUrl":"https://aoctrl.com/siemens/3RW4028-1BB15","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4028-1BB15","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4028-1BB15 soft starter, Size S0, 38 A at 40 °C, 600 V insulation voltage, screw-type terminals, integrated bypass contact system, 110-230 V DC control supply.","salesMarkdown":"## Active production — what it means for your BOM line The 3RW4028-1BB15: No stock-holding claim is made here — the supply posture is quoted to order. ## Rated current and thermal derating — the real operating envelope The continuous rated current is 38 A at 40 °C ambient. The derating temperature threshold is 40 °C, so any panel ambient above that must be factored into the motor full-load current match. The minimum load requirement is 20% of the rated current — below that the soft starter may not trigger the thyristors reliably. This matters when the connected motor is oversized for the actual load. Insulation voltage is rated at 600 V, with a pollution degree of 3 per IEC 60947-4-2. The operating frequency range is 50 to 60 Hz, covering standard industrial mains worldwide. ## Mounting, clearances, and panel integration Size S0 footprint: 45 mm wide, 125 mm high, 155 mm deep. Fastening is by screw and snap-on mounting onto a DIN rail — the snap-on feature speeds panel assembly without tools. Clearance requirements: 60 mm upwards, 40 mm downwards, 15 mm at the sides. These are the minimum free-air gaps for natural convection cooling; crowding the enclosure beyond these limits forces derating. Mounting position restrictions depend on whether an additional fan is fitted. With the fan, the unit can be rotated +/-90° on a vertical surface and tilted +/-22.5° front-to-back. Without the fan, rotation is limited to +/-10° and tilt to +/-10°. ## Control supply and wiring The control supply voltage accepts 110 to 230 V DC — a wide-range input that simplifies panel wiring across different control voltages without a separate transformer tap. Auxiliary and control circuit terminals are also screw-type, sized for 20 to 14 AWG. The front clamping point accepts one 8 AWG or two conductors from 16 to 10 AWG. Maximum motor wire length is 300 m — beyond that, voltage drop and reflected wave effects on the thyristor stack may cause nuisance tripping or premature failure. ## Integrated bypass and protection features An integrated bypass contact system is built in — once the motor reaches full speed, the bypass contacts close to short-circuit the thyristors, eliminating heat dissipation in the power semiconductors during steady-state running. This means the soft starter runs cool and the enclosure heat load is lower than a non-bypassed design. Motor overload protection and intrinsic device protection are both included. The adjustable current limitation allows setting the start current between 20% and 100% of the rated current, matching the application's torque requirements. External reset capability is provided — the fault signal is indicated by a red display. There is no motor brake output on this variant. ## Environmental ratings and storage conditions Storage temperature range is -40 to +80 °C. During storage, the unit meets IEC 60721 classifications 1K6 (occasional condensation), 1C2 (no salt mist), 1S2 (sand must not enter the device), and 1M4 (mechanical vibration). The reference code per EN 61346-2 is Q, designating a power switching device in the functional classification system.","metaTitle":"Siemens 3RW4028-1BB15 SIRIUS Soft Starter, 38A, 600V","metaDescription":"Siemens 3RW4028-1BB15 SIRIUS soft starter, 38A at 40°C, 600V insulation voltage, Size S0, screw terminals, integrated bypass.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Soft Starters"],"specifications":{"Depth":"155mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"45mm","title":"3RW4028-1BB15","Height":"125mm","Upwards":"60mm","Downwards":"40mm","Thyristors":"Yes","At The Side":"15mm","description":"SIRIUS soft starter S0 38 A, 22 kW/500 V, 40 °C 400-600 V AC, 110-230 V AC/DC Screw 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%","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 40 °C rated value":"38A","at 50 °C rated value":"34A","at 60 °C rated value":"31A","For Auxiliary Contacts":"2x (20 ... 14)","For Main Current Circuit":"screw-type 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)","control supply voltage 1 at DC":"110 ... 230V","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"red","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"screw-type 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","control supply voltage 1 at AC at 50 Hz":"110 ... 230V","control supply voltage 1 at AC at 60 Hz":"110 ... 230V","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":"No","at standard circuit at 40 °C rated value":"22kW","at standard circuit at 50 °C rated value":"30hp","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":"400 ... 600V","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%","For Auxiliary Contacts Finely Stranded With Core End Processing":"2x (20 ... 16)","relative negative tolerance of the control supply voltage at DC":"-15%","relative positive tolerance of the control supply voltage at DC":"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":"19W","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":"23A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b5249e352b21f3b0ebf1c081f1b125a4.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=510447&mlfb=3RW4028-1BB15"},"ai":{"faq":[{"question":"What are the key ratings of the 3RW4028-1BB15?","answer":"Rated 38 A at 40 °C, 600 V insulation voltage, Size S0 form factor (45x125x155 mm). Control supply is 110-230 V DC. Integrated bypass contact system, screw-type terminals, adjustable current limitation, and motor overload protection are all included."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4028-1BB15","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/3RW4028-1BB15 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}}