{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW3028-2BB14","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW3028-2BB14","canonicalUrl":"https://aoctrl.com/siemens/3RW3028-2BB14","factsUrl":"https://aoctrl.com/api/mcp/products/3RW3028-2BB14","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW3028-2BB14 soft starter, Size S0, 38 A at 40 °C, 45 mm width, spring-loaded terminals, integrated bypass, screw and snap-on mounting.","salesMarkdown":"## 38 A at 40 °C — the derating curve sets the real limit The 3RW3028-2BB14: The 40 °C figure is the baseline for sizing against the motor FLA; above that, the continuous current drops by roughly 10% per 10 °C rise. The integrated bypass contact system carries the motor current after start-up, shifting the heat load off the thyristors. This means the derating curve matters most during the start cycle — once bypassed, the thermal limit is the bypass contactor's rating, not the silicon junction. ## Spring-loaded terminals and mounting — what ships in the box Both the main current circuit and the auxiliary/control circuit use spring-loaded terminals. The main terminals accept 16-8 AWG solid or stranded; the auxiliary terminals take 24-14 AWG. No screw torque check needed — the spring cage holds the conductor and signals a seated termination with a tactile click. Mounting is dual-mode: screw-fix or snap-on onto a DIN rail. The 45 mm width fits a standard S0 frame slot. The mounting position allows ±10° rotation and ±10° tilt forward/backward from vertical — useful when the panel layout forces an angled rail. ## Clearance, cable length, and pollution class Keep 60 mm clearance above and 40 mm below the unit, plus 15 mm at the sides, for airflow and wiring access. The maximum motor cable length is 300 m — beyond that, capacitive charging current may cause nuisance tripping on the soft starter's internal protection. The 600 V rated insulation voltage supports 480 V and 575 V line supplies with margin.","metaTitle":"Siemens 3RW3028-2BB14 SIRIUS Soft Starter, 38A, Size S0","metaDescription":"Siemens 3RW3028-2BB14 SIRIUS soft starter, 38A rated at 40°C, size S0 frame, 45mm wide. Spring-loaded terminals, integrated bypass. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Soft Starters"],"specifications":{"Depth":"150mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"45mm","title":"3RW3028-2BB14","Height":"150mm","Upwards":"60mm","Downwards":"40mm","Thyristors":"Yes","At The Side":"15mm","description":"SIRIUS soft starter S0 38 A, 18.5 kW/400 V, 40 °C 200-480 V AC, 110-230 V AC/DC spring-type terminals","During Storage":"-40 ... +80°C","External Reset":"No","lifecycle_stage":"current","During Operation":"-25 ... +60°C","Fastening Method":"screw and snap-on mounting","Minimum Load [%]":"10%","For Main Contacts":"16 ... 8","Mounting Position":"With vertical mounting surface +/-10° rotatable, with vertical mounting surface +/- 10° 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":"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 (24 ... 14)","For Main Current Circuit":"spring-loaded terminals","Motor Overload Protection":"No","Intrinsic Device Protection":"No","Adjustable Current Limitation":"No","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":"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","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 (0.25 ... 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":"18.5kW","at standard circuit at 50 °C rated value":"25hp","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"1","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":"-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%"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/61919f50f4b2cf962cacd44b1390d983.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=195995&mlfb=3RW3028-2BB14"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW3028-2BB14","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/3RW3028-2BB14 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}}