{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RW4436-2BC44","brand":"Siemens","brandSlug":"siemens","productSlug":"3RW4436-2BC44","canonicalUrl":"https://aoctrl.com/siemens/3RW4436-2BC44","factsUrl":"https://aoctrl.com/api/mcp/products/3RW4436-2BC44","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS soft starter, 3RW4436-2BC44, 281 A rated at 40 °C, 690 V insulation voltage, 50/60 Hz, thyristor-based motor overload protection.","salesMarkdown":"## What this 281 A soft starter does on the line The Siemens 3RW4436-2BC44 is a SIRIUS soft starter rated 281 A at 40 °C, 251 A at 50 °C, and 217 A at 60 °C, with an insulation voltage of 690 V and operating frequency of 50 to 60 Hz. Above that, you derate: at 50 °C you lose about 11% of the rated current, at 60 °C about 23%. If the panel runs hot — common in a crowded MCC or near a dryer section — size the motor FLA against the derated number, not the headline 281 A. The unit measures 200 mm high by 170 mm wide by 270 mm deep and uses screw fixing to a vertical mounting surface. It can be rotated ±90° or tilted ±22.5° front-to-back, so it fits in a swing-frame or a tight backpanel without forcing a custom bracket. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides — the side gap is tight enough that adjacent devices can sit nearly flush, but the vertical gap matters for convection cooling of the thyristor stack. Main circuit connection is via busbar; the terminal range accepts 25 to 120 mm² stranded or 4 to 250 kcmil. For auxiliary contacts, the terminals take 2x (0.25 to 1.5 mm²) solid or 2x (24 to 16 AWG). The maximum wire length from the soft starter to the motor is 500 m — beyond that, capacitive charging current can interfere with the thyristor firing and the internal bypass. ## Protection and control features The soft starter includes motor overload protection and intrinsic device protection — meaning it can protect both the motor and its own thyristors from overcurrent and overtemperature without an external overload relay. The adjustable current limitation lets you set the starting current between 8% and 100% of the rated current, which is useful for soft-starting pumps or conveyors where you need to limit inrush to avoid tripping upstream breakers or mechanical shock to the load. An external reset input is provided, so the starter can be reset remotely from a PLC or control room — no need to walk to the panel after a fault. The display version shows fault signals on the unit itself, which helps a technician on the floor identify the reason for a trip without a laptop. It supports inside-delta circuit wiring, which reduces the current through the thyristors to 58% of the line current — useful for derating the unit on a high-inertia load where the motor FLA exceeds the soft starter's rating. ## Environmental and pollution rating Storage temperature range is -25 to +80 °C; during operation the ambient limit is 60 °C. The derating temperature threshold is 40 °C, above which you must reduce the rated current as shown in the spec table.","metaTitle":"Siemens 3RW4436-2BC44 SIRIUS Soft Starter, 281A","metaDescription":"Siemens SIRIUS 3RW4436-2BC44 soft starter, 281A at 40°C, 690V insulation voltage. Thyristor-based motor overload protection. Active lifecycle.","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":"3RW4436-2BC44","Height":"200mm","Upwards":"100mm","Stranded":"25 ... 120 mm²","Downwards":"75mm","Thyristors":"Yes","At The Side":"5mm","description":"SIRIUS soft starter Values at 400 V, 40 °C standard: 162 A, 90 kW Inside-delta: 281 A, 160 kW 200-460 V AC, 230 V AC spring-type terminals!!! Phased-out product!!! Successor is SIRIUS 3RW5, Preferred successor type is >>3RW5536-2HA14<<","During Storage":"-25 ... +80°C","External Reset":"Yes","Finely Stranded":"16 ... 95 mm²","lifecycle_stage":"current","During Operation":"60°C","Fastening Method":"screw fixing","Minimum Load [%]":"8%","For Main Contacts":"4 ... 250 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":"281A","at 50 °C rated value":"251A","at 60 °C rated value":"217A","For Auxiliary Contacts":"2x (24 ... 16)","For Main Current Circuit":"busbar connection","Motor Overload Protection":"Yes","Using Both Clamping Points":"max. 2x 1/0","Intrinsic Device Protection":"Yes","Adjustable Current Limitation":"Yes","Using The Back Clamping Point":"6 ... 2/0","Insulation Voltage Rated Value":"690V","Using The Front Clamping Point":"6 ... 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","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":"90kW","at standard circuit at 50 °C rated value":"100hp","Finely Stranded Without Core End Processing":"max. 1x 50 mm², 1x 70 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":"160kW","at inside-delta circuit at 50 °C rated value":"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":"95W","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":"32A","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/a4bae83cf377a369a39c35f1985e179a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=53083&mlfb=3RW4436-2BC44"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RW4436-2BC44","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/3RW4436-2BC44 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}}