{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4427-1BC45","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4427-1BC45","canonicalUrl":"https://aoctrl.com/siemens/3RW4427-1BC45","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4427-1BC45","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4427-1BC45 soft starter, 161 A at 40 °C, 690 V insulation voltage, 50/60 Hz, integrated bypass, screw terminals.","salesMarkdown":"## Panel fit and mounting — 192 x 170 x 270 mm The 3RW4427-1BC45 measures 192 mm high, 170 mm wide, and 270 mm deep. It mounts via screw fixing and accepts a vertical mounting surface with ±90° rotation and ±22.5° tilt front-to-back. Clearance for airflow: 100 mm above, 75 mm below, 5 mm at the sides. ## Termination and wiring — box terminals, dual conductors Main circuit connections use box terminals accepting 2x (4 … 50 mm²) stranded or 2x (10 … 1/0 AWG) using both clamping points. The front and back clamping points each accept 10 … 2/0 AWG. Maximum motor cable length is 500 m. ## Soft start topology — thyristor stack with integrated bypass The 3RW4427-1BC45 uses thyristors for the soft-start ramp and an integrated bypass contact system that closes once the motor is at full speed. This bypass eliminates thyristor conduction losses during run, keeping the enclosure cooler and improving efficiency. It supports inside-delta circuit wiring, which reduces the current through each soft starter phase to 58% of the line current — useful for retrofitting into existing delta-wound motor circuits without upsizing the starter. ## Protection and control — adjustable current limit, motor overload Adjustable current limitation lets you set the start current between 8% and 100% of the rated motor current. The unit provides motor overload protection and intrinsic device protection. Fault signals are shown on an integrated display. An external reset input allows remote clearing of trip conditions without opening the panel door. ## Environmental and electrical ratings Insulation voltage rated at 690 V, pollution degree 3 per IEC 60947-4-2. Storage temperature range -25 … +80 °C; maximum ambient during operation is 60 °C. The derating temperature threshold is 40 °C.","metaTitle":"Siemens 3RW4427-1BC45 Soft Starter, 161 A, SIRIUS","metaDescription":"Siemens 3RW4427-1BC45 SIRIUS soft starter, 161 A at 40 °C, 690 V insulation, integrated bypass. Active production, quoted to order. Request a quote.","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":"3RW4427-1BC45","Height":"192mm","Upwards":"100mm","Stranded":"2x (4 ... 50 mm²)","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 500 V, 40 °C standard: 93 A, 55 kW Inside-delta: 161 A, 110 kW 400-600 V AC, 230 V AC Screw terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5527-1HA16<<","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":"230V","at 60 Hz rated value":"230V","at 40 °C rated value":"161A","at 50 °C rated value":"142A","at 60 °C rated value":"125A","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":"55kW","at standard circuit at 50 °C rated value":"75hp","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":"110kW","at inside-delta circuit at 50 °C rated value":"125hp","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":"55W","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":"18A","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/1b5319614dff805dd28b9ae96a220409.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=299974&mlfb=3RW4427-1BC45"},"ai":{"faq":[{"question":"What is the 3RW4427-1BC45 rated current at different temperatures?","answer":"At 40 °C the continuous rating is 161 A, derating to 142 A at 50 °C and 125 A at 60 °C."},{"question":"Does the 3RW4427-1BC45 have an integrated bypass?","answer":"Yes, it includes an integrated bypass contact system that closes after the start ramp, removing the thyristors from the circuit during run."},{"question":"What wire sizes does the 3RW4427-1BC45 accept?","answer":"Main circuit box terminals accept 2x (4 … 50 mm²) stranded or 2x (10 … 1/0 AWG) using both clamping points."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4427-1BC45","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/3RW4427-1BC45 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}}