{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4457-2BC34","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4457-2BC34","canonicalUrl":"https://aoctrl.com/siemens/3RW4457-2BC34","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4457-2BC34","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4457-2BC34 soft starter, 1,524 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":"## Rated current and thermal derating — the real motor ceiling The 3RW4457-2BC34 is rated 1,524 A at 40 °C ambient — that's the full-load current it can start and run continuously when the panel ambient stays at or below 40 °C. At 50 °C the ceiling drops to 1,351 A, and at 60 °C it's 1,200 A. If your enclosure runs hot — say a non-ventilated cabinet next to a motor — the derating curve is the number that governs the real motor size, not the 40 °C headline. The integrated bypass contact system shunts the thyristors out of the circuit once the motor reaches full speed. That means the heat dissipation in run mode is just the bypass contact resistance, not the semiconductor forward drop — so the derating matters less for continuous running than for the start cycle. ## Inside-delta wiring and motor protection — what the terminals mean This soft starter supports inside-delta circuit wiring, which connects the soft starter in series with each motor winding rather than in the supply lines. That reduces the current the soft starter sees to 58% of the line current — a 1,524 A rated unit can start a motor with a line FLA up to roughly 2,630 A when wired inside-delta. Motor overload protection and intrinsic device protection are built in — no separate overload relay needed. The adjustable current limitation lets you set the start current anywhere from 8% minimum load up to the rated ceiling, so you can tune the ramp for a soft start on a conveyor or a pump. The main circuit terminals are busbar connection, accepting stranded cable 70–240 mm² or finely stranded 50–240 mm². Auxiliary and control wiring lands on spring-loaded terminals — no screwdriver torque check needed, which saves time on a panel with dozens of control wires. ## Mounting and integration into the panel Mounting is screw fixing — not DIN-rail snap-on. The envelope is 640 mm high, 510 mm wide, 290 mm deep. Plan for 100 mm clearance above and 75 mm below for ventilation and cable bending radius; side clearance is 5 mm. The mounting position allows a vertical surface with ±90° rotation and ±22.5° tilt forward/back. That gives flexibility in a tight cabinet — you can orient the display for readability without relocating the whole assembly. Operating temperature range is 60 °C max during operation; storage range is -25 to +80 °C.","metaTitle":"Siemens 3RW4457-2BC34 SIRIUS Soft Starter, 1,524 A, 690 V","metaDescription":"Siemens 3RW4457-2BC34 SIRIUS soft starter, rated 1,524 A at 40°C, 690 V insulation. Integrated bypass, inside-delta wiring, motor overload protection.","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":"3RW4457-2BC34","Height":"640mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 460 V, 50 °C standard: 780 A, 700 hp Inside-delta: 1351 A, 1200 hp 200-460 V AC, 115 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":"115V","at 60 Hz rated value":"115V","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":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/9ee85f3b85e3803bcf79b20a75af11b2.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=483431&mlfb=3RW4457-2BC34"},"ai":{"faq":[{"question":"What is the rated current of 3RW4457-2BC34 at different ambient temperatures?","answer":"At 40 °C ambient the rated current is 1,524 A. The 40 °C figure is the headline rating; the derated values govern the real motor size in a warm enclosure."},{"question":"What compliance documentation does Siemens provide for 3RW4457-2BC34?","answer":"The soft starter carries a pollution degree 3 rating per IEC 60947-4-2 and an insulation voltage of 690 V. Standard Siemens documentation includes the declaration of conformity and the product manual; specific RoHS/REACH/UL certificates are available from Siemens support or your distributor upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4457-2BC34","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/3RW4457-2BC34 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}}