{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4075-2BB35","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4075-2BB35","canonicalUrl":"https://aoctrl.com/siemens/3RW4075-2BB35","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4075-2BB35","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4075-2BB35 soft starter, S12 frame, 356 A at 40 °C, 50/60 Hz, 600 V insulation, screw fixing.","salesMarkdown":"## Rated current and thermal derating — what the numbers mean for the motor circuit The 3RW4075-2BB35: That 40 °C derating temperature means the full 356 A is only available when the enclosure ambient stays at or below 40 °C — above that, the current must be reduced per the derating curve, not guessed. For a 315 A motor in a 50 °C panel, this unit still delivers the full motor FLA without oversizing. The S12 frame size and 600 V rated insulation voltage place it in the heavy end of the SIRIUS soft starter family, sized for large conveyors, pumps, and compressors where the starting current ramp matters more than a VFD's speed control. ## Connection and mounting — what fits in the panel Main circuit connection accepts busbar or cable: stranded 70–240 mm², finely stranded 50–240 mm², or AWG 2/0–500 kcmil using both clamping points. The back clamping point takes 250–500 kcmil, the front takes 3/0–600 kcmil — so you can land incoming and outgoing conductors on separate points without a splice bar. Screw fixing to the mounting surface, with dimensions 230 mm high by 160 mm wide by 278 mm deep. Clearance requirements: 100 mm upwards, 75 mm downwards, 5 mm at the sides — the side clearance is tight, so adjacent devices can sit close, but the vertical clearance above and below must be kept for airflow and cable bending radius. ## Protection and control — built-in overload and adjustable current limit Motor overload protection is integrated, and the device includes intrinsic device protection — so the soft starter monitors its own thyristor temperature and shuts down before damage. Adjustable current limitation lets you set the starting current between 20% and the rated current, which is useful for soft-starting high-inertia loads without tripping upstream protection. External reset input allows remote fault reset from a PLC or pushbutton, avoiding a trip to the panel. Pollution degree 3 per IEC 60947-4-2 means it's rated for industrial environments with conductive dust or occasional condensation — no need for a sealed enclosure in a typical motor control centre.","metaTitle":"Siemens 3RW4075-2BB35 SIRIUS Soft Starter, 356 A, S12","metaDescription":"Siemens 3RW4075-2BB35 SIRIUS soft starter, 356 A at 40 °C, 600 V insulation, S12 frame. Active production, sourced to order. Request a quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"278mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"160mm","title":"3RW4075-2BB35","Height":"230mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter S12 315 A, 300 hp/575 V, 50 °C 400-600 V AC, 115 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5075-2AB15<<","During Storage":"-40 ... +80°C","External Reset":"Yes","Finely Stranded":"50 ... 240 mm²","lifecycle_stage":"current","During Operation":"-25 ... +60°C","Fastening Method":"screw fixing","Minimum Load [%]":"20%","For Main Contacts":"2/0 ... 500 kcmil","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":"115V","at 60 Hz rated value":"115V","at 40 °C rated value":"356A","at 50 °C rated value":"315A","at 60 °C rated value":"280A","For Auxiliary Contacts":"2x (24 ... 16)","For Main Current Circuit":"busbar connection","Motor Overload Protection":"Yes","Using Both Clamping Points":"min. 2x 2/0, max. 2x 500 kcmil","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Size Of Engine Control Device":"S12","Using The Back Clamping Point":"250 ... 500 kcmil","Insulation Voltage Rated Value":"600V","Using The Front Clamping Point":"3/0 ... 600 kcmil","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"red","Integrated Bypass Contact System":"Yes","during storage acc. to IEC 60721":"1K6 (only occasional condensation), 1C2 (no salt mist), 1S2 (sand must not get inside the devices), 1M4","For Auxiliary And Control Circuit":"spring-loaded terminals","during operation acc. 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 acc. to IEC 60721":"2K2, 2C1, 2S1, 2M2 (max. fall height 0.3 m)","Product Component Motor Brake Output":"No","reference code acc. to DIN EN 61346-2":"Q","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":"250kW","at standard circuit at 50 °C rated value":"300hp","Finely Stranded Without Core End Processing":"min. 2x 50 mm², max. 2x 185 mm²","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","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","touch protection on the front acc. to IEC 60529":"finger-safe, for vertical contact from the front with cover","continuous operating current [% of Ie] at 40 °C":"115%","Operating Voltage At Standard Circuit Rated Value":"400 ... 600V","protection class IP on the front acc. to IEC 60529":"IP00; IP20 with cover","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 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":"125W","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":"131A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d6cd1b3b4231212a1e39b56c587abf4f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=372680&mlfb=3RW4075-2BB35"},"ai":{"faq":[{"question":"How do I get pricing and availability for 3RW4075-2BB35?","answer":"Pricing and stock are confirmed at quote time against your BOM quantity. Submit an RFQ through this listing; availability and lead time are provided in the quotation."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4075-2BB35","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/3RW4075-2BB35 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}}