{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4457-2BC44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4457-2BC44","canonicalUrl":"https://aoctrl.com/siemens/3RW4457-2BC44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4457-2BC44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4457-2BC44 soft starter, 1524 A at 40 °C, 690 V insulation voltage, 50/60 Hz, integrated bypass contact system, inside-delta circuit, screw fixing, 640 x 510 x 290 mm.","salesMarkdown":"## 1524 A at 40 °C — the derating curve sets the real limit The 3RW4457-2BC44: That figure drops to 1351 A at 50 °C and 1200 A at 60 °C — the derating is linear with temperature, so the panel ambient inside the enclosure, not the motor room temperature, governs the continuous current you can pass through the thyristors. Operating frequency is 50/60 Hz, control voltage 230 V at both line frequencies. ## Integrated bypass and inside-delta wiring An integrated bypass contact system closes after the start ramp, shunting the thyristors and eliminating semiconductor conduction losses during run. This means the 1524 A rating applies to the bypass path, not just the SCRs — the thermal load on the enclosure drops once the motor is at speed. Inside-delta circuit wiring is supported, which reduces the line-side current to 58% of the motor full-load current in a delta-connected motor. For a 1524 A motor FLC, the soft starter sees roughly 884 A per phase on the line side — a significant saving on upstream cable and contactor sizing. ## Mounting, clearances, and conductor terminations Screw fixing to a vertical mounting surface, with ±90° rotation and ±22.5° tilt forward/backward allowed. Dimensions: 640 mm height, 510 mm width, 290 mm depth — plan the enclosure backplate accordingly. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides. These are the minimum air gaps for natural convection cooling and arc-flash containment per the installation guide. Main current circuit connection is via busbar (not cable lugs). Auxiliary and control circuits use spring-loaded terminals — no screw torque check needed on those. ## Protection and control features Motor overload protection is built in — no separate overload relay required. Adjustable current limitation lets you set the start current between 100% and the rated current ceiling, matching the motor inrush to the supply capacity. Minimum load detection threshold is 8% of the rated current — below that the soft starter may not detect the motor is connected. External reset input allows remote fault recovery without opening the panel door. A local display shows fault codes. Intrinsic device protection covers the thyristors against over-temperature and over-current. The pollution degree is 3 per IEC 60947-4-2 — suitable for industrial environments with conductive dust or occasional condensation.","metaTitle":"Siemens 3RW4457-2BC44 SIRIUS Soft Starter, 1524 A at 40°C","metaDescription":"Siemens 3RW4457-2BC44 SIRIUS soft starter, rated 1524 A at 40°C, 690 V insulation. Active production, quoted to order.","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":"3RW4457-2BC44","Height":"640mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 400 V, 40 °C standard: 880 A, 500 kW Inside-delta: 1524 A, 900 kW 200-460 V AC, 230 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5556-2HA14<<","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":"230V","at 60 Hz rated value":"230V","at 40 °C rated value":"1 524A","at 50 °C rated value":"1 351A","at 60 °C rated value":"1 200A","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":"900kW","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":"200 ... 460V","contact rating of auxiliary contacts according to UL":"B300 / R300","Operating Voltage At Inside-Delta Circuit Rated Value":"200 ... 460V","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":"250W","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":"176A","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":45,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/62c681b32fa2eda139ba7bae0044d92e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=447935&mlfb=3RW4457-2BC44"},"ai":{"faq":[{"question":"What is the maximum motor cable length for the 3RW4457-2BC44?","answer":"The maximum wire length from the soft starter to the motor is 500 m. This is the total cable run per phase, not the sum of all three phases — longer runs increase capacitive charging current and may cause nuisance trips on the thyristor gate drive."},{"question":"Does the 3RW4457-2BC44 include a motor brake output?","answer":"Yes, a motor brake output is integrated as a product component. This allows direct control of a DC injection brake or mechanical brake coil without a separate contactor, simplifying the control wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4457-2BC44","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/3RW4457-2BC44 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}}