{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4424-3BC34","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4424-3BC34","canonicalUrl":"https://aoctrl.com/siemens/3RW4424-3BC34","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4424-3BC34","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RW4424-3BC34 soft starter, 81 A at 40 °C, 690 V insulation voltage, integrated bypass contact, inside-delta circuit, 115 V control voltage, screw fixing.","salesMarkdown":"The Siemens 3RW4424-3BC34 is a SIRIUS soft starter, a thyristor-based motor starting device that ramps voltage to limit inrush current during start-up. It's rated 81 A at 40 °C, 73 A at 50 °C, and 64 A at 60 °C, with an insulation voltage of 690 V and operating frequency of 50/60 Hz. The 115 V control voltage is the same at both 50 and 60 Hz. An integrated bypass contact system means the thyristors are shorted out once the motor reaches full speed, eliminating heat dissipation from the semiconductors during run. That's a key difference from open-loop soft starters that keep the SCRs in circuit and need derating for continuous duty. It supports inside-delta circuit wiring, which lets you connect the soft starter in the motor's delta loop rather than line-side. That reduces the current rating required for the soft starter to about 58% of the motor FLA — useful for squeezing a larger motor onto a given frame size. The 81 A rating at 40 °C is the headline number, but the derating curve matters: at 50 °C it's 73 A, at 60 °C it's 64 A. The derating temperature threshold is 40 °C, so above that you lose roughly 9 A per 10 °C rise. Minimum load is 8% of the rated current. That's low enough for most standard induction motors, but if you're starting a very small motor or a lightly loaded one, check the actual running current against that floor. Adjustable current limitation is built in, so you can set the start current anywhere from about 1.5x to 4x FLA depending on the load. Motor overload protection and intrinsic device protection (over-temperature, phase imbalance) are included — no separate overload relay needed for most installations. That's the standard for most control panels, not a special case. Clearance requirements: 100 mm above, 75 mm below, and just 5 mm at the sides. That side clearance is tight — you can pack these on a panel backplate with minimal air gap, but the vertical clearance is non-negotiable for heat rise. Dimensions are 192 mm high, 170 mm wide, 270 mm deep. The depth includes the heat sink and terminals, so account for that when laying out the gland plate or enclosure depth. Main circuit connections use box terminals accepting stranded 2x (4 to 50 mm²) or solid 2x (0.25 to 1.5 mm²). Auxiliary and control circuit connections are spring-loaded terminals. That's a mix: power wiring gets a screw clamp, control wiring gets a push-in spring cage. Keep your ferrule kit handy for the control side. Maximum motor cable length is 500 m — enough for most installations, but if you're running long feeders from a remote MCC, check that against your cable capacitance and the soft starter's dv/dt rating. For compliance documentation: the SIRIUS line typically carries CE, UL, CSA, and EAC markings, plus RoHS and REACH declarations. Specific certification numbers for this order code should be verified against the manufacturer's declaration of conformity, but the product class is broadly approved for industrial control panels worldwide. ## What's on the front panel A display for fault signals is included — shows error codes directly on the device, no need to wire up a separate HMI or PLC to read out the fault reason. External reset input is present, so you can wire a remote pushbutton to clear faults without opening the panel door. A motor brake output is built in — that's a relay output that energizes when the soft starter is in the 'stop' state, typically used to release a mechanical brake on the motor shaft. Saves an external interposing relay.","metaTitle":"Siemens 3RW4424-3BC34 SIRIUS Soft Starter, 81A at 40°C","metaDescription":"Siemens SIRIUS 3RW4424-3BC34 soft starter, 81A rated at 40°C, 690V insulation voltage, integrated bypass, inside-delta circuit, adjustable current limitation, motor overload protec","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Soft Starters"],"specifications":{"Depth":"270mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"170mm","title":"3RW4424-3BC34","Height":"192mm","Upwards":"100mm","Stranded":"2x (4 ... 50 mm²)","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 460 V, 50 °C standard: 42 A, 25 hp Inside-delta: 73 A, 50 hp 200-460 V AC, 115 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5524-3HA14<<","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":"115V","at 60 Hz rated value":"115V","at 40 °C rated value":"81A","at 50 °C rated value":"73A","at 60 °C rated value":"64A","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":"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","for AWG cables for auxiliary contacts":"2x (24 ... 16)","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":"22kW","at standard circuit at 50 °C rated value":"25hp","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":"45kW","at inside-delta circuit at 50 °C rated value":"50hp","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":"32W","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":"9A","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":"$1,869.00","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d84df8e5298ecb4ba35b19fe0f952145.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=253890&mlfb=3RW4424-3BC34"},"ai":{"faq":[{"question":"What clearance do I need around this soft starter in the panel?","answer":"100 mm above, 75 mm below, and just 5 mm at the sides. The side clearance is very tight — you can mount these side-by-side with almost no gap. The vertical clearance is the critical dimension for heat dissipation from the heat sink."},{"question":"What kind of terminals does it use?","answer":"Main circuit connections use box terminals (screw clamp) accepting stranded 2x (4 to 50 mm²) or solid 2x (0.25 to 1.5 mm²). Auxiliary and control circuits use spring-loaded terminals. Keep ferrules for the control wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4424-3BC34","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/3RW4424-3BC34 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}}