{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4458-2BC45","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4458-2BC45","canonicalUrl":"https://aoctrl.com/siemens/3RW4458-2BC45","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4458-2BC45","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS soft starter 3RW4458-2BC45, 1680 A at 40 °C, 230 V at 50/60 Hz, with integrated bypass, inside-delta circuit, and display for fault signal.","salesMarkdown":"## Soft starter for heavy motor loads The Siemens 3RW4458-2BC45 is a SIRIUS soft starter rated 1680 A at 40 °C, dropping to 1472 A at 50 °C and 1316 A at 60 °C — so it handles a 1680 A motor start at a 40 °C ambient, but you need to derate if the panel runs hotter. Insulation voltage is 690 V, operating frequency 50 to 60 Hz, with a minimum load of 8% of the rated current, meaning it won't soft-start a motor that's too small for its range. ## Inside-delta wiring and bypass This unit supports inside-delta circuit connection, which lets you wire the soft starter in the delta leg of a six-lead motor — that reduces the current the soft starter sees to 58% of the line current, so you can size the unit smaller for a given motor. It also has an integrated bypass contact system, so after the motor reaches full speed, the bypass contacts close and the thyristors are taken out of circuit — no heat dissipation from the power semiconductors during run, which keeps the enclosure cooler and extends thyristor life. The main current circuit uses busbar connection; the auxiliary and control circuit uses spring-loaded terminals, which is faster to wire than screw clamps and doesn't loosen under vibration. Clearances: 100 mm upwards, 75 mm downwards, 5 mm at the side. Dimensions are 510 mm wide by 640 mm high by 290 mm deep — it's a large unit, so check the backpanel space before cutting the gland plate. Stranded cable goes 70 to 240 mm²; finely stranded 50 to 240 mm²; for main contacts it also accepts 2/0 to 500 kcmil. Solid wire is 2x (0.25 to 1.5 mm²) for the auxiliary contacts only. ## Protection and control features Motor overload protection is built in, along with intrinsic device protection — it monitors the thyristor junction temperature and shuts down before the semiconductors overheat. Adjustable current limitation lets you set the start current between 8% and the full rated current, which is useful for limiting inrush on weak lines or soft-load conveyors. External reset is supported, so you can wire a remote reset button to clear a fault without opening the panel door. A display shows the fault signal, which speeds up diagnostics on the floor. There's also a motor brake output component, so it can control a DC injection brake if the motor is equipped. This is a current-production part in the SIRIUS family — no obsolescence notice on record. For volume or BOM-freeze purchases, submit an RFQ and we'll pull the latest factory lead time and price.","metaTitle":"Siemens 3RW4458-2BC45 SIRIUS Soft Starter, 1680 A at 40 °C","metaDescription":"Siemens 3RW4458-2BC45 SIRIUS soft starter, rated 1680 A at 40 °C. Current-production part with inside-delta capability and integrated bypass.","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":"3RW4458-2BC45","Height":"640mm","Upwards":"100mm","Stranded":"70 ... 240 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 500 V, 40 °C standard: 970 A, 710 kW Inside-delta: 1680 A, 1200 kW 400-600 V AC, 230 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5556-2HA16<<","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":"230V","at 60 Hz rated value":"230V","at 40 °C rated value":"1 680A","at 50 °C rated value":"1 472A","at 60 °C rated value":"1 316A","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":"710kW","at standard circuit at 50 °C rated value":"950hp","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":"1 200kW","at inside-delta circuit at 50 °C rated value":"1 650hp","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":"270W","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":"194A","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/85e68ad161dae7b8766165210746730e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=273781&mlfb=3RW4458-2BC45"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4458-2BC45","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/3RW4458-2BC45 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}}