{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4455-2BC35","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4455-2BC35","canonicalUrl":"https://aoctrl.com/siemens/3RW4455-2BC35","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4455-2BC35","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4455-2BC35 soft starter, 1200 A at 40 °C, 690 V insulation voltage, 50/60 Hz, integrated bypass contact system, screw fixing.","salesMarkdown":"## Rated current and thermal derating The 3RW4455-2BC35 delivers 1200 A at 40 °C ambient — this is the base rating for sizing the motor branch circuit. The derating temperature threshold is 40 °C; above that the thyristor junction temperature limits the output. For a pump or conveyor pulling 1000 A FLA in a 50 °C panel, this unit still has headroom — but at 60 °C the margin narrows to 46 A below the 1000 A mark. ## Integrated bypass and inside-delta wiring The integrated bypass contact system shorts the thyristors after the motor reaches full speed, eliminating SCR conduction losses during run. This means the heat sink sees only the start transient, not the full-load continuous dissipation — a meaningful advantage for panel fill factor and ventilation design. Inside-delta circuit capability allows the soft starter to be wired in the motor delta loop rather than the supply line, reducing the current through each SCR leg by roughly 42% compared to standard in-line connection. This is the wiring topology to use when the motor is delta-connected and the starter is sized for the phase current, not the line current. ## Mounting dimensions and panel layout Mounting position allows a vertical surface with +/-90° rotation and +/-22.5° tilt forward/back. Clearance requirements: 100 mm upward, 75 mm downward, 5 mm at the sides — the side gap is tight, so adjacent components must not block airflow across the heatsink fins. ## Termination and wiring Main current circuit termination is busbar connection — expect flat copper bars, not cable lugs, for the 1200 A path. The stranded wire range for the main circuit is 70–240 mm², finely stranded 50–240 mm², and AWG/kcmil 2/0–500. ## Protection and control features Motor overload protection and intrinsic device protection are built in — no separate overload relay needed in the motor branch circuit. Adjustable current limitation lets the starting current be set between 8% and 100% of the rated current, with a minimum load threshold of 8% below which the starter may not reliably detect the motor. A display for fault signals and external reset capability simplify troubleshooting on the line. The unit also includes a motor brake output component for applications requiring DC injection braking at stop. ## Lifecycle and sourcing For volume commitments or scheduled builds, confirm lead time and MOQ at quote.","metaTitle":"Siemens 3RW4455-2BC35 SIRIUS Soft Starter, 1200A at 40°C","metaDescription":"Siemens 3RW4455-2BC35 SIRIUS soft starter, 1200A rated at 40°C, 690V insulation, integrated bypass. Active production, quoted to order against BOM quantities.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"290mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"510mm","title":"3RW4455-2BC35","Height":"640mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 575 V, 50 °C standard: 615 A, 700 hp Inside-delta: 1065 A, 1200 hp 400-600 V AC, 115 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5553-2HA16<<","During Storage":"-25 ... +80°C","External Reset":"Yes","Finely Stranded":"50 ... 240 mm²","lifecycle_stage":"current","During Operation":"60°C","Fastening Method":"screw fixing","Minimum Load [%]":"8%","For Main Contacts":"2/0 ... 500 kcmil","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":"1 200A","at 50 °C rated value":"1 065A","at 60 °C rated value":"954A","For Auxiliary Contacts":"2x (24 ... 16)","For Main Current Circuit":"busbar connection","Motor Overload Protection":"Yes","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Insulation Voltage Rated Value":"690V","Operating Frequency Rated Value":"50 ... 60Hz","Display Version For Fault Signal":"Display","Integrated Bypass Contact System":"Yes","For Auxiliary And Control Circuit":"spring-loaded 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 (0.25 ... 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":"500kW","at standard circuit at 50 °C rated value":"700hp","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":"800kW","at inside-delta circuit at 50 °C rated value":"1 200hp","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%","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":"220W","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":"138A","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/7366d004b94430dbddf6824f2e61475b.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=472536&mlfb=3RW4455-2BC35"},"ai":{"faq":[{"question":"What is the rated current of the 3RW4455-2BC35 at different temperatures?","answer":"At 40 °C the continuous rating is 1200 A. The derating temperature threshold is 40 °C."},{"question":"How is the 3RW4455-2BC35 terminated for main power?","answer":"The main current circuit uses busbar connection. Stranded wire range is 70–240 mm², finely stranded 50–240 mm², and AWG/kcmil 2/0–500. Auxiliary and control circuits use spring-loaded terminals."},{"question":"Does the 3RW4455-2BC35 include an integrated bypass?","answer":"Yes, it has an integrated bypass contact system that shorts the thyristors after the motor reaches full speed, eliminating SCR conduction losses during run. It also supports inside-delta circuit wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4455-2BC35","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/3RW4455-2BC35 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}