{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4027-1TB05","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4027-1TB05","canonicalUrl":"https://aoctrl.com/siemens/3RW4027-1TB05","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4027-1TB05","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4027-1TB05 soft starter, size S0, 32 A at 40 °C, 45 mm width, integrated bypass contact system, screw terminals.","salesMarkdown":"The 3RW4027-1TB05: It integrates a bypass contact system to remove the thyristors from the circuit after start, reducing heat dissipation during run. Mounting is screw or snap-on to DIN rail; the 45 mm width and 125 mm height fit a standard panel layout. The 155 mm depth leaves clearance for wiring at the side (15 mm) and above (60 mm). ## Current ratings and thermal derating The 32 A rating at 40 °C is the base figure for a 50/60 Hz motor load. Derate to 29 A at 50 °C and 26 A at 60 °C — the temperature rise inside the enclosure must stay below the 40 °C derating threshold or the available current drops. Pollution degree 3 per IEC 60947-4-2 means the unit tolerates conductive deposits in industrial atmospheres. The integrated bypass contact system carries the full motor current after start, so the thyristors only see the start transient. This extends the duty cycle for frequent starts and keeps the enclosure heat load lower than a non-bypassed soft starter.","metaTitle":"Siemens 3RW4027-1TB05 SIRIUS Soft Starter, 32 A, 40 °C","metaDescription":"Siemens 3RW4027-1TB05 SIRIUS soft starter, 32 A at 40 °C, size S0, 45 mm wide, integrated bypass. Active production, quoted to order. Request a quote.","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":"3RW4027-1TB05","Height":"125mm","Upwards":"60mm","Downwards":"40mm","Thyristors":"Yes","At The Side":"15mm","description":"SIRIUS soft starter S0 32 A, 18.5 k kW/500 V, 40 °C 400-600 V AC, 24 V AC/DC Screw terminals Thermistor motor protection","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 50 Hz rated value":"24V","at 60 Hz rated value":"24V","at 40 °C rated value":"32A","at 50 °C rated value":"29A","at 60 °C rated value":"26A","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)","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","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":"18.5kW","at standard circuit at 50 °C rated value":"25hp","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":"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":"-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":"13W","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":"17A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e32ea2f269d1aa3685ad0cf44c4669a7.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=284125&mlfb=3RW4027-1TB05"},"ai":{"faq":[{"question":"What are the key ratings for the 3RW4027-1TB05?","answer":"Rated 32 A at 40 °C, 29 A at 50 °C, 26 A at 60 °C. Insulation voltage 600 V, operating frequency 50/60 Hz. Size S0 frame, 45 mm wide. Integrated bypass contact system and motor overload protection are included."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4027-1TB05","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/3RW4027-1TB05 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}}