{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4425-1BC35","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4425-1BC35","canonicalUrl":"https://aoctrl.com/siemens/3RW4425-1BC35","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4425-1BC35","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4425-1BC35 soft starter, 99 A at 40 °C, 690 V insulation voltage, 50/60 Hz, integrated bypass, screw terminals, IP20.","salesMarkdown":"## 99 A at 40 °C — the real operating limit The 3RW4425-1BC35: That 40 °C figure is the baseline — if your panel ambient runs hotter, the continuous current drops accordingly. Plan the enclosure ventilation around the 60 °C ceiling if the soft starter shares space with drives or transformers. The integrated bypass contact system means the thyristors only handle the start ramp; once at full speed, the bypass contactor carries the load current. This cuts the heat dissipation in the cabinet during run and extends the thyristor life — the bypass takes the thermal stress off the semiconductors. ## Mounting and clearance — fits standard panels Dimensions are 170 mm wide, 192 mm high, 270 mm deep. Screw fixing to the mounting surface. The mounting position allows vertical surface orientation with ±90° rotation and ±22.5° tilt front-to-back — useful when the panel layout forces an angled install. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides. The 100 mm top gap is the critical one — that's the hot air exhaust path. Skimping on the top clearance derates the unit faster than the bottom gap. ## Wiring and protection — what the terminals accept Main current circuit uses box terminals accepting 2x (4... 50 mm²) stranded or 2x (10... 1/0 AWG) using both clamping points. That's a standard industrial terminal set — no special crimp tooling needed. Built-in motor overload protection and intrinsic device protection mean you don't need a separate overload relay in most installations. The adjustable current limitation lets you set the start current between 8% and the full rated current — useful for gentle starts on conveyors or pumps. ## Inside-delta wiring and cable length The 3RW4425-1BC35 supports inside-delta circuit wiring, which reduces the current through the soft starter to 58% of the motor FLA — effectively letting a 99 A unit control a motor drawing up to about 170 A line current. That's a common trick for larger motors where the soft starter cost scales with current rating. Maximum motor cable length is 500 m. Beyond that, the cable capacitance can cause nuisance tripping from leakage currents during the thyristor firing. For long cable runs, keep the total below 500 m or add an output reactor. Pollution degree 3 per IEC 60947-4-2 — suitable for industrial environments with conductive dust or condensation.","metaTitle":"Siemens 3RW4425-1BC35 SIRIUS Soft Starter, 99 A at 40 °C","metaDescription":"Siemens 3RW4425-1BC35 SIRIUS soft starter, 99 A at 40 °C, 690 V insulation voltage, integrated bypass. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"270mm","Solid":"2x (0.5 ... 2.5 mm²)","Width":"170mm","title":"3RW4425-1BC35","Height":"192mm","Upwards":"100mm","Stranded":"2x (4 ... 50 mm²)","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 575 V, 50 °C standard: 51 A, 40 hp Inside-delta: 88 A, 75 hp 400-600 V AC, 115 V AC Screw terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5525-1HA16<<","During Storage":"-25 ... +80°C","External Reset":"Yes","lifecycle_stage":"current","During Operation":"60°C","Fastening Method":"screw fixing","Minimum Load [%]":"8%","Mounting Position":"with vertical mounting surface +/-90° rotatable, with vertical mounting surface +/- 22.5° 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":"500m","Derating Temperature":"40°C","Inside-Delta Circuit":"Yes","at 50 Hz rated value":"115V","at 60 Hz rated value":"115V","at 40 °C rated value":"99A","at 50 °C rated value":"88A","at 60 °C rated value":"78A","For Auxiliary Contacts":"2x (20 ... 14)","For Main Current Circuit":"box terminal","Motor Overload Protection":"Yes","Using Both Clamping Points":"2x (10 ... 1/0)","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Using The Back Clamping Point":"10 ... 2/0","Insulation Voltage Rated Value":"690V","Using The Front Clamping Point":"10 ... 2/0","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"Display","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"screw-type terminals","Product Component Motor Brake Output":"Yes","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":"37kW","at standard circuit at 50 °C rated value":"40hp","Finely Stranded Without Core End Processing":"2x (4 ... 35 mm²)","number of CO contacts for auxiliary contacts":"1","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"3","Type Of Voltage Of The Control Supply Voltage":"AC","at inside-delta circuit at 40 °C rated value":"55kW","at inside-delta circuit at 50 °C rated value":"75hp","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","Operating Voltage At Inside-Delta Circuit Rated Value":"400 ... 600V","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 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":"36W","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":"11A","Relative Negative Tolerance Of The Operating Voltage At Inside-Delta Circuit":"-15%","Relative Positive Tolerance Of The Operating Voltage At Inside-Delta Circuit":"10%"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/b9fa7a23ead9a3d618602ca37a19dfee.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=343638&mlfb=3RW4425-1BC35"},"ai":{"faq":[{"question":"What is the 3RW4425-1BC35 rated current at different temperatures?","answer":"The soft starter is rated 99 A at 40 °C, derating to 88 A at 50 °C and 78 A at 60 °C. The 40 °C figure is the baseline — if your panel ambient runs hotter, the continuous current drops accordingly."},{"question":"What clearance is needed around the 3RW4425-1BC35 for ventilation?","answer":"Minimum clearances are 100 mm above, 75 mm below, and 5 mm at the sides. The 100 mm top gap is the critical one for hot air exhaust — skimping on it derates the unit faster than the bottom gap."},{"question":"How can I order the 3RW4425-1BC35 and get a quote?","answer":"Submit an RFQ for current pricing and availability confirmation."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4425-1BC35","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/3RW4425-1BC35 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}}