{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4038-1BB05","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4038-1BB05","canonicalUrl":"https://aoctrl.com/siemens/3RW4038-1BB05","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4038-1BB05","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4038-1BB05 soft starter, size S2, 72 A at 40 °C, 24 V AC/DC control voltage, screw-type terminals, integrated bypass contact system.","salesMarkdown":"## Soft starter for motor starting — 72 A, size S2 The 3RW4038-1BB05: Integrated bypass contact system means the thyristors are shorted out once the motor is at speed — no continuous heat sink load, and the bypass contact carries the full running current. ## Mounting and wiring — screw terminals, size S2 Size S2 frame: 160 mm high, 55 mm wide, 170 mm deep. Screw-and-snap-on mounting to DIN rail. Clearance: 60 mm above, 40 mm below, 30 mm at the side. The mounting position is restricted without an additional fan — vertical surface only, ±10° rotatable and ±10° tilt. ## Protection and control features Motor overload protection is built in, and the current limitation is adjustable — set the start current between 20 % and the device's rated maximum to match the load's acceleration torque. Intrinsic device protection covers the soft starter itself against overtemperature and phase imbalance. Pollution degree 3 per IEC 60947-4-2 — suitable for industrial environments with conductive dust. Insulation voltage rated 600 V, operating frequency 50... 60 Hz. Ambient range during operation -25... +60 °C, storage -40... +80 °C. Sourced through authorized distribution; volume pricing and lead time confirmed at RFQ against the BOM quantity. The part is not stocked on the shelf here — each order is quoted individually.","metaTitle":"Siemens 3RW4038-1BB05 SIRIUS Soft Starter, 72 A, 24 V AC/DC","metaDescription":"Siemens 3RW4038-1BB05 SIRIUS soft starter, 72 A at 40 °C, 24 V control, size S2. Active production, screw terminals, integrated bypass. Quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Soft Starters"],"specifications":{"Depth":"170mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"55mm","title":"3RW4038-1BB05","Height":"160mm","Upwards":"60mm","Stranded":"2x (1.5 ... 25 mm²)","Downwards":"40mm","Thyristors":"Yes","At The Side":"30mm","description":"SIRIUS soft starter S2 72 A, 45 kW/500 V, 40 °C 400-600 V AC, 24 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 50 Hz rated value":"24V","at 60 Hz rated value":"24V","at 40 °C rated value":"72A","at 50 °C rated value":"62A","at 60 °C rated value":"60A","For Auxiliary Contacts":"2x (20 ... 14)","For Main Current Circuit":"screw-type terminals","Motor Overload Protection":"Yes","Using Both Clamping Points":"2x (16 ... 2)","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Size Of Engine Control Device":"S2","Using The Back Clamping Point":"16 ... 2","Insulation Voltage Rated Value":"600V","Using The Front Clamping Point":"18 ... 2","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":"No","at standard circuit at 40 °C rated value":"45kW","at standard circuit at 50 °C rated value":"60hp","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":"15W","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":"35A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/e2126a59570d90077e4c160c1c4aa94c.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=255260&mlfb=3RW4038-1BB05"},"ai":{"faq":[{"question":"What is the maximum motor current for 3RW4038-1BB05 at 40 °C?","answer":"72 A at 40 °C. Derate to 62 A at 50 °C and 60 A at 60 °C. The 40 °C figure is the standard rating; the 60 °C ceiling applies when the panel ambient is at the upper limit."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4038-1BB05","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/3RW4038-1BB05 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}}